Builtin Functions

Numeric Functions

abs

Syntax:
```
abs(numeric_value)
```
Computes the absolute value of the argument.
Arguments:
- numeric_value: a tinyint/smallint/integer/bigint/float/double value.
Return Value:
- The absolute value of the argument with the same type as the input argument,
- missing if the argument is a missing value,
- null if the argument is a null value,
- any other non-numeric input value will cause a type error.

Example:

{ "v1": abs(2013), "v2": abs(-4036), "v3": abs(0), "v4": abs(float("-2013.5")), "v5": abs(double("-2013.593823748327284")) };

The expected result is:

{ "v1": 2013, "v2": 4036, "v3": 0, "v4": 2013.5, "v5": 2013.5938237483274 }

acos

Syntax:
```
acos(numeric_value)
```
Computes the arc cosine value of the argument.
Arguments:
- numeric_value: a tinyint/smallint/integer/bigint/float/double value.
Return Value:
- the double arc cosine in radians for the argument, if the argument is in the range of -1 (inclusive) to 1 (inclusive),
- missing if the argument is a missing value,
- null if the argument is a null value,
- any other non-numeric input value will cause a type error,
- "NaN" for other legitimate numeric values.

Example:

{ "v1": acos(1), "v2": acos(2), "v3": acos(0), "v4": acos(float("0.5")), "v5": acos(double("-0.5")) };

The expected result is:

{ "v1": 0.0, "v2": "NaN", "v3": 1.5707963267948966, "v4": 1.0471975511965979, "v5": 2.0943951023931957 }

asin

Syntax:
```
asin(numeric_value)
```
Computes the arc sine value of the argument.
Arguments:
- numeric_value: a tinyint/smallint/integer/bigint/float/double value.
Return Value:
- the double arc sin in radians for the argument, if the argument is in the range of -1 (inclusive) to 1 (inclusive),
- missing if the argument is a missing value,
- null if the argument is a null value,
- any other non-numeric input value will cause a type error,
- "NaN" for other legitimate numeric values.

Example:

{ "v1": asin(1), "v2": asin(2), "v3": asin(0), "v4": asin(float("0.5")), "v5": asin(double("-0.5")) };

The expected result is:

{ "v1": 1.5707963267948966, "v2": "NaN", "v3": 0.0, "v4": 0.5235987755982989, "v5": -0.5235987755982989 }

atan

Syntax:
```
atan(numeric_value)
```
Computes the arc tangent value of the argument.
Arguments:
- numeric_value: a tinyint/smallint/integer/bigint/float/double value.
Return Value:
- the double arc tangent in radians for the argument,
- missing if the argument is a missing value,
- null if the argument is a null value,
- any other non-numeric input value will cause a type error.

Example:

{ "v1": atan(1), "v2": atan(2), "v3": atan(0), "v4": atan(float("0.5")), "v5": atan(double("1000")) };

The expected result is:

{ "v1": 0.7853981633974483, "v2": 1.1071487177940904, "v3": 0.0, "v4": 0.4636476090008061, "v5": 1.5697963271282298 }

atan2

Syntax:
```
atan2(numeric_value1, numeric_value2)
```
Computes the arc tangent value of numeric_value2/numeric_value1.
Arguments:
- numeric_value1: a tinyint/smallint/integer/bigint/float/double value,
- numeric_value2: a tinyint/smallint/integer/bigint/float/double value.
Return Value:
- the double arc tangent in radians for numeric_value1 and numeric_value2,
- missing if any argument is a missing value,
- null if any argument is a null value but no argument is a missing value,
- any other non-numeric input value will cause a type error.

Example:

{ "v1": atan2(1, 2), "v2": atan2(0, 4), "v3": atan2(float("0.5"), double("-0.5")) };

The expected result is:

{ "v1": 0.4636476090008061, "v2": 0.0, "v3": 2.356194490192345 }

ceil

Syntax:
```
ceil(numeric_value)
```
Computes the smallest (closest to negative infinity) number with no fractional part that is not less than the value of the argument. If the argument is already equal to mathematical integer, then the result is the same as the argument.
Arguments:
- numeric_value: a tinyint/smallint/integer/bigint/float/double value.
Return Value:
- The ceiling value for the given number in the same type as the input argument,
- missing if the argument is a missing value,
- null if the argument is a null value,
- any other non-numeric input value will cause a type error.

Example:

{
  "v1": ceil(2013),
  "v2": ceil(-4036),
  "v3": ceil(0.3),
  "v4": ceil(float("-2013.2")),
  "v5": ceil(double("-2013.893823748327284"))
};

The expected result is:

{ "v1": 2013, "v2": -4036, "v3": 1.0, "v4": -2013.0, "v5": -2013.0 }

cos

Syntax:
```
cos(numeric_value)
```
Computes the cosine value of the argument.
Arguments:
- numeric_value: a tinyint/smallint/integer/bigint/float/double value.
Return Value:
- the double cosine value for the argument,
- missing if the argument is a missing value,
- null if the argument is a null value,
- any other non-numeric input value will cause a type error.

Example:

{ "v1": cos(1), "v2": cos(2), "v3": cos(0), "v4": cos(float("0.5")), "v5": cos(double("1000")) };

The expected result is:

{ "v1": 0.5403023058681398, "v2": -0.4161468365471424, "v3": 1.0, "v4": 0.8775825618903728, "v5": 0.562379076290703 }

degrees

Syntax:
```
degrees(numeric_value)
```
Converts radians to degrees
Arguments:
- numeric_value: a tinyint/smallint/integer/bigint/float/double value.
Return Value:
- The degrees value for the given radians value. The returned value has type double,
- missing if the argument is a missing value,
- null if the argument is a null value,
- any other non-numeric input value will cause a type error.
Example:
```
{ "v1": degrees(pi()) };
```
The expected result is:
```
{ "v1": 180.0 }
```

e

Syntax:
```
e()
```
Return Value:
- e (base of the natural logarithm)
Example:
```
{ "v1": e() };
```
The expected result is:
```
{ "v1": 2.718281828459045 }
```

exp

Syntax:
```
exp(numeric_value)
```
Computes e^{numeric_value}.
Arguments:
- numeric_value: a tinyint/smallint/integer/bigint/float/double value.
Return Value:
- e^{numeric_value},
- missing if the argument is a missing value,
- null if the argument is a null value,
- any other non-numeric input value will cause a type error.

Example:

{ "v1": exp(1), "v2": exp(2), "v3": exp(0), "v4": exp(float("0.5")), "v5": exp(double("1000")) };

The expected result is:

{ "v1": 2.718281828459045, "v2": 7.38905609893065, "v3": 1.0, "v4": 1.6487212707001282, "v5": "Infinity" }

floor

Syntax:
```
floor(numeric_value)
```
Computes the largest (closest to positive infinity) number with no fractional part that is not greater than the value. If the argument is already equal to mathematical integer, then the result is the same as the argument.
Arguments:
- numeric_value: a tinyint/smallint/integer/bigint/float/double value.
Return Value:
- The floor value for the given number in the same type as the input argument,
- missing if the argument is a missing value,
- null if the argument is a null value,
- any other non-numeric input value will cause a type error.

Example:

{
  "v1": floor(2013),
  "v2": floor(-4036),
  "v3": floor(0.8),
  "v4": floor(float("-2013.2")),
  "v5": floor(double("-2013.893823748327284"))
};

The expected result is:

{ "v1": 2013, "v2": -4036, "v3": 0.0, "v4": -2014.0, "v5": -2014.0 }

ln

Syntax:
```
ln(numeric_value)
```
Computes log_enumeric_value.
Arguments:
- numeric_value: a tinyint/smallint/integer/bigint/float/double value.
Return Value:
- log_enumeric_value,
- missing if the argument is a missing value,
- null if the argument is a null value,
- any other non-numeric input value will cause a type error.

Example:

{ "v1": ln(1), "v2": ln(2), "v3": ln(0), "v4": ln(float("0.5")), "v5": ln(double("1000")) };

The expected result is:

{ "v1": 0.0, "v2": 0.6931471805599453, "v3": "-Infinity", "v4": -0.6931471805599453, "v5": 6.907755278982137 }

log

Syntax:
```
log(numeric_value)
```
Computes log₁₀numeric_value.
Arguments:
- numeric_value: a tinyint/smallint/integer/bigint/float/double value.
Return Value:
- log₁₀numeric_value,
- missing if the argument is a missing value,
- null if the argument is a null value,
- any other non-numeric input value will cause a type error.

Example:

{ "v1": log(1), "v2": log(2), "v3": log(0), "v4": log(float("0.5")), "v5": log(double("1000")) };

The expected result is:

{ "v1": 0.0, "v2": 0.3010299956639812, "v3": "-Infinity", "v4": -0.3010299956639812, "v5": 3.0 }

pi

Syntax:
```
pi()
```
Return Value:
- Pi
Example:
```
{ "v1": pi() };
```
The expected result is:
```
{ "v1": 3.141592653589793 }
```

power

Syntax:
```
power(numeric_value1, numeric_value2)
```
Computes numeric_value1^{numeric_value2}.
Arguments:
- numeric_value1: a tinyint/smallint/integer/bigint/float/double value,
- numeric_value2: a tinyint/smallint/integer/bigint/float/double value.
Return Value:
- numeric_value1^{numeric_value2},
- missing if any argument is a missing value,
- null if any argument is a null value but no argument is a missing value,
- any other non-numeric input value will cause a type error.

Example:

{ "v1": power(1, 2), "v3": power(0, 4), "v4": power(float("0.5"), double("-0.5")) };

The expected result is:

{ "v1": 1, "v3": 0, "v4": 1.4142135623730951 }

radians

Syntax:
```
radians(numeric_value)
```
Converts degrees to radians
Arguments:
- numeric_value: a tinyint/smallint/integer/bigint/float/double value.
Return Value:
- The radians value for the given degrees value. The returned value has type double,
- missing if the argument is a missing value,
- null if the argument is a null value,
- any other non-numeric input value will cause a type error.
Example:
```
{ "v1": radians(180) };
```
The expected result is:
```
{ "v1": 3.141592653589793 }
```

round

Syntax:
```
round(numeric_value)
```
Computes the number with no fractional part that is closest (and also closest to positive infinity) to the argument.
Arguments:
- numeric_value: a tinyint/smallint/integer/bigint/float/double value.
Return Value:
- The rounded value for the given number in the same type as the input argument,
- missing if the argument is a missing value,
- null if the argument is a null value,
- any other non-numeric input value will cause a type error.

Example:

{
  "v1": round(2013),
  "v2": round(-4036),
  "v3": round(0.8),
  "v4": round(float("-2013.256")),
  "v5": round(double("-2013.893823748327284"))
};

The expected result is:

{ "v1": 2013, "v2": -4036, "v3": 1.0, "v4": -2013.0, "v5": -2014.0 }

sign

Syntax:
```
sign(numeric_value)
```
Computes the sign of the argument.
Arguments:
- numeric_value: a tinyint/smallint/integer/bigint/float/double value.
Return Value:
- the sign (a tinyint) of the argument, -1 for negative values, 0 for 0, and 1 for positive values,
- missing if the argument is a missing value,
- null if the argument is a null value,
- any other non-numeric input value will cause a type error.

Example:

{ "v1": sign(1), "v2": sign(2), "v3": sign(0), "v4": sign(float("0.5")), "v5": sign(double("-1000")) };

The expected result is:

{ "v1": 1, "v2": 1, "v3": 0, "v4": 1, "v5": -1 }

sin

Syntax:
```
sin(numeric_value)
```
Computes the sine value of the argument.
Arguments:
- numeric_value: a tinyint/smallint/integer/bigint/float/double value.
Return Value:
- the double sine value for the argument,
- missing if the argument is a missing value,
- null if the argument is a null value,
- any other non-numeric input value will cause a type error.

Example:

{ "v1": sin(1), "v2": sin(2), "v3": sin(0), "v4": sin(float("0.5")), "v5": sin(double("1000")) };

The expected result is:

{ "v1": 0.8414709848078965, "v2": 0.9092974268256817, "v3": 0.0, "v4": 0.479425538604203, "v5": 0.8268795405320025 }

sqrt

Syntax:
```
sqrt(numeric_value)
```
Computes the square root of the argument.
Arguments:
- numeric_value: a tinyint/smallint/integer/bigint/float/double value.
Return Value:
- the double square root value for the argument,
- missing if the argument is a missing value,
- null if the argument is a null value,
- any other non-numeric input value will cause a type error.

Example:

{ "v1": sqrt(1), "v2": sqrt(2), "v3": sqrt(0), "v4": sqrt(float("0.5")), "v5": sqrt(double("1000")) };

The expected result is:

{ "v1": 1.0, "v2": 1.4142135623730951, "v3": 0.0, "v4": 0.7071067811865476, "v5": 31.622776601683793 }

tan

Syntax:
```
tan(numeric_value)
```
Computes the tangent value of the argument.
Arguments:
- numeric_value: a tinyint/smallint/integer/bigint/float/double value.
Return Value:
- the double tangent value for the argument,
- missing if the argument is a missing value,
- null if the argument is a null value,
- any other non-numeric input value will cause a type error.

Example:

{ "v1": tan(1), "v2": tan(2), "v3": tan(0), "v4": tan(float("0.5")), "v5": tan(double("1000")) };

The expected result is:

{ "v1": 1.5574077246549023, "v2": -2.185039863261519, "v3": 0.0, "v4": 0.5463024898437905, "v5": 1.4703241557027185 }

trunc

Syntax:
```
trunc(numeric_value, number_digits)
```
Truncates the number to the given number of integer digits to the right of the decimal point (left if digits is negative). Digits is 0 if not given.
Arguments:
- numeric_value: a tinyint/smallint/integer/bigint/float/double value,
- number_digits: a tinyint/smallint/integer/bigint value.
Return Value:
- the double tangent value for the argument,
- missing if any argument is a missing value,
- null if any argument is a null value but no argument is missing,
- a type error will be raised if:
  - the first argument is any other non-numeric value,
  - the second argument is any other non-tinyint, non-smallint, non-integer, and non-bigint value.

Example:

{ "v1": trunc(1, 1), "v2": trunc(2, -2), "v3": trunc(0.122, 2), "v4": trunc(float("11.52"), -1), "v5": trunc(double("1000.5252"), 3) };

The expected result is:

{ "v1": 1, "v2": 2, "v3": 0.12, "v4": 10.0, "v5": 1000.525 }

random

Syntax:
```
random([expr])
```
Returns a pseudo-random number with optional seed.
Arguments:
- expr: A number, or an expression that evaluates to a number.
Return Value:
- Returns a number between 0 and 1.
- Returns NULL if expr is not a number.
Example:
```
random(123);
```
A possible result is:
```
0.029199439979853525
```

String Functions

concat

Syntax:
```
concat(string1, string2, ...)
```
Returns a concatenated string from arguments.
Arguments:
- string1: a string value,
- string2: a string value,
- ….
Return Value:
- a concatenated string from arguments,
- missing if any argument is a missing value,
- null if any argument is a null value but no argument is a missing value,
- any other non-string input value will cause a type error.

Example:

concat("test ", "driven ", "development");

The expected result is:
```
"test driven development"
```

contains

Syntax:
```
contains(string, substring_to_contain)
```
Checks whether the string string contains the string substring_to_contain
Arguments:
- string : a string that might contain the given substring,
- substring_to_contain : a target string that might be contained.
Return Value:
- a boolean value, true if string contains substring_to_contain,
- missing if any argument is a missing value,
- null if any argument is a null value but no argument is a missing value,
- any other non-string input value will cause a type error,
- false otherwise.
NOTE: an n_gram index can be utilized for this function.

Example:

{ "v1": contains("I like x-phone", "phone"), "v2": contains("one", "phone") };

The expected result is:
```
{ "v1": true, "v2": false }
```

ends_with

Syntax:

ends_with(string, substring_to_end_with)

Checks whether the string string ends with the string substring_to_end_with.
Arguments:
- string : a string that might end with the given string,
- substring_to_end_with : a string that might be contained as the ending substring.
Return Value:
- a boolean value, true if string contains substring_to_contain,
- missing if any argument is a missing value,
- null if any argument is a null value but no argument is a missing value,
- any other non-string input value will cause a type error,
- false otherwise.

Example:

{
  "v1": ends_with(" love product-b its shortcut_menu is awesome:)", ":)"),
  "v2": ends_with(" awsome:)", ":-)")
};

The expected result is:
```
{ "v1": true, "v2": false }
```

initcap (or title)

Syntax:
```
initcap(string)
```
Converts a given string string so that the first letter of each word is uppercase and every other letter is lowercase. The function has an alias called "title".
Arguments:
- string : a string to be converted.
Return Value:
- a string as the title form of the given string,
- missing if the argument is a missing value,
- null if the argument is a null value,
- any other non-string input value will cause a type error.

Example:

{ "v1": initcap("ANALYTICS is here!"), "v2": title("ANALYTICS is here!") };

The expected result is:

{ "v1": "Analytics Is Here!", "v2": "Analytics Is Here!" }

length

Syntax:
```
length(string)
```
Returns the length of the string string.
Arguments:
- string : a string or null that represents the string to be checked.
Return Value:
- an bigint that represents the length of string,
- missing if the argument is a missing value,
- null if the argument is a null value,
- any other non-string input value will cause a type error.
Example:
```
length("test string");
```
The expected result is:
```
11
```

lower

Syntax:
```
lower(string)
```
Converts a given string string to its lowercase form.
Arguments:
- string : a string to be converted.
Return Value:
- a string as the lowercase form of the given string,
- missing if the argument is a missing value,
- null if the argument is a null value,
- any other non-string input value will cause a type error.
Example:
```
lower("ANALYTICS");
```
The expected result is:
```
"analytics"
```

ltrim

Syntax:
```
ltrim(string[, chars]);
```
Returns a new string with all leading characters that appear in chars removed. By default, white space is the character to trim.
Arguments:
- string : a string to be trimmed,
- chars : a string that contains characters that are used to trim.
Return Value:
- a trimmed, new string,
- missing if any argument is a missing value,
- null if any argument is a null value but no argument is a missing value,
- any other non-string input value will cause a type error.
Example:
```
ltrim("me like x-phone", "eml");
```
The expected result is:
```
" like x-phone"
```

position

Syntax:
```
position(string, string_pattern)
```
Returns the first position of string_pattern within string.
Arguments:
- string : a string that might contain the pattern,
- string_pattern : a pattern string to be matched.
Return Value:
- the first position that string_pattern appears within string (starting at 0), or -1 if it does not appear,
- missing if any argument is a missing value,
- null if any argument is a null value but no argument is a missing value,
- any other non-string input value will cause a type error.

Example:

{
  "v1": position("ppphonepp", "phone"),
  "v2": position("hone", "phone")
};

The expected result is:
```
{ "v1": 3, "v2": -1 }
```

regexp_contains

Syntax:

regexp_contains(string, string_pattern[, string_flags])

Checks whether the strings string contains the regular expression pattern string_pattern (a Java regular expression pattern).
Arguments:
- string : a string that might contain the pattern,
- string_pattern : a pattern string to be matched,
- string_flag : (Optional) a string with flags to be used during regular expression matching.
  - The following modes are enabled with these flags: dotall (s), multiline (m), case_insensitive (i), and comments and whitespace (x).
Return Value:
- a boolean, returns true if string contains the pattern string_pattern,
- missing if any argument is a missing value,
- null if any argument is a null value but no argument is a missing value,
- any other non-string input value will cause a type error,
- false otherwise.

Example:

{
  "v1": regexp_contains("pphonepp", "p*hone"),
  "v2": regexp_contains("hone", "p+hone")
}

The expected result is:
```
{ "v1": true, "v2": false }
```

regexp_like

Syntax:

regexp_like(string, string_pattern[, string_flags])

Checks whether the string string exactly matches the regular expression pattern string_pattern (a Java regular expression pattern).
Arguments:
- string : a string that might contain the pattern,
- string_pattern : a pattern string that might be contained,
- string_flag : (Optional) a string with flags to be used during regular expression matching.
  - The following modes are enabled with these flags: dotall (s), multiline (m), case_insensitive (i), and comments and whitespace (x).
Return Value:
- a boolean value, true if string contains the pattern string_pattern,
- missing if any argument is a missing value,
- null if any argument is a null value but no argument is a missing value,
- any other non-string input value will cause a type error,
- false otherwise.

Example:

{
  "v1": regexp_like(" can't stand acast the network is horrible:(", ".*acast.*"),
  "v2": regexp_like("acast", ".*acst.*")
};

The expected result is:
```
{ "v1": true, "v2": false }
```

regexp_position

Syntax:

regexp_position(string, string_pattern[, string_flags])

Returns first position of the regular expression string_pattern (a Java regular expression pattern) within string.
Arguments:
- string : a string that might contain the pattern,
- string_pattern : a pattern string to be matched,
- string_flag : (Optional) a string with flags to be used during regular expression matching.
  - The following modes are enabled with these flags: dotall (s), multiline (m), case_insensitive (i), and comments and whitespace (x).
Return Value:
- the first position that the regular expression string_pattern appears in string (starting at 0), or -1 if it does not appear.
- missing if any argument is a missing value,
- null if any argument is a null value but no argument is a missing value,
- any other non-string input value will cause a type error.

Example:

{
  "v1": regexp_position("pphonepp", "p*hone"),
  "v2": regexp_position("hone", "p+hone")
};

The expected result is:
```
{ "v1": 1, "v2": -1 }
```

regexp_replace

Syntax:

regexp_replace(string, string_pattern, string_replacement[, string_flags])
regexp_replace(string, string_pattern, string_replacement[, replacement_limit])

Checks whether the string string matches the given regular expression pattern string_pattern (a Java regular expression pattern), and replaces the matched pattern string_pattern with the new pattern string_replacement.
Arguments:
- string : a string that might contain the pattern,
- string_pattern : a pattern string to be matched,
- string_replacement : a pattern string to be used as the replacement,
- string_flag : (Optional) a string with flags to be used during replace.
  - The following modes are enabled with these flags: dotall (s), multiline (m), case_insensitive (i), and comments and whitespace (x).
- replacement_limit: (Optional) an integer specifying the maximum number of replacements to make (if negative then all occurrences will be replaced)
Return Value:
- Returns a string that is obtained after the replacements,
- missing if any argument is a missing value,
- any other non-string input value will cause a type error,
- null if any argument is a null value but no argument is a missing value.

Example:

regexp_replace(" like x-phone the voicemail_service is awesome", " like x-phone", "like product-a")

The expected result is:

"like product-a the voicemail_service is awesome"

repeat

Syntax:
```
repeat(string, n)
```
Returns a string formed by repeating the input string n times.
Arguments:
- string : a string to be repeated,
- n : an tinyint/smallint/integer/bigint value - how many times the string should be repeated.
Return Value:
- a string that repeats the input string n times,
- missing if any argument is a missing value,
- null if any argument is a null value but no argument is a missing value,
- a type error will be raised if:
  - the first argument is any other non-string value,
  - or, the second argument is not a tinyint, smallint, integer, or bigint.
Example:
```
repeat("test", 3);
```
The expected result is:
```
"testtesttest"
```

replace

Syntax:

replace(string, search_string, replacement_string[, limit])

Finds occurrences of the given substring search_string in the input string string and replaces them with the new substring replacement_string.
Arguments:
- string : an input string,
- search_string : a string substring to be searched for,
- replacement_string : a string to be used as the replacement,
- limit : (Optional) an integer - maximum number of occurrences to be replaced. If not specified or negative then all occurrences will be replaced
Return Value:
- Returns a string that is obtained after the replacements,
- missing if any argument is a missing value,
- any other non-string input value or non-integer limit will cause a type error,
- null if any argument is a null value but no argument is a missing value.

Example:

{
  "v1": replace(" like x-phone the voicemail_service is awesome", " like x-phone", "like product-a"),
  "v2": replace("x-phone and x-phone", "x-phone", "product-a", 1)
};

The expected result is:

{
  "v1": "like product-a the voicemail_service is awesome",
  "v2": "product-a and x-phone"
}

reverse

Syntax:
```
reverse(string)
```
Returns a string formed by reversing characters in the input string.
Arguments:
- string : a string to be reversed
Return Value:
- a string containing characters from the the input string in the reverse order,
- missing if any argument is a missing value,
- null if any argument is a null value but no argument is a missing value,
- a type error will be raised if:
  - the first argument is any other non-string value
Example:
```
reverse("hello");
```
The expected result is:
```
"olleh"
```

rtrim

Syntax:
```
rtrim(string[, chars]);
```
Returns a new string with all trailing characters that appear in chars removed. By default, white space is the character to trim.
Arguments:
- string : a string to be trimmed,
- chars : a string that contains characters that are used to trim.
Return Value:
- a trimmed, new string,
- missing if any argument is a missing value,
- null if any argument is a null value but no argument is a missing value,
- any other non-string input value will cause a type error.

Example:

{
  "v1": rtrim("i like x-phone", "x-phone"),
  "v2": rtrim("i like x-phone", "onexph")
};

The expected result is:
```
{ "v1": "i like ", "v2": "i like " }
```

split

Syntax:
```
split(string, sep)
```
Splits the input string into an array of substrings separated by the string sep.
Arguments:
- string : a string to be split.
Return Value:
- an array of substrings by splitting the input string by sep,
- missing if the argument is a missing value,
- null if the argument is a null value,
- any other non-string input value will cause a type error.
Example:
```
split("test driven development", " ");
```
The expected result is:
```
[ "test", "driven", "development" ]
```

starts_with

Syntax:

starts_with(string, substring_to_start_with)

Checks whether the string string starts with the string substring_to_start_with.
Arguments:
- string : a string that might start with the given string.
- substring_to_start_with : a string that might be contained as the starting substring.
Return Value:
- a boolean, returns true if string starts with the string substring_to_start_with,
- missing if any argument is a missing value,
- null if any argument is a null value but no argument is a missing value,
- any other non-string input value will cause a type error,
- false otherwise.

Example:

{
  "v1" : starts_with(" like the plan, amazing", " like"),
  "v2" : starts_with("I like the plan, amazing", " like")
};

The expected result is:
```
{ "v1": true, "v2": false }
```

substr

Syntax:
```
substr(string, offset[, length])
```
Returns the substring from the given string string based on the given start offset offset with the optional length.
Arguments:
- string : a string to be extracted,
- offset : an tinyint/smallint/integer/bigint value as the starting offset of the substring in string (starting at 0). If negative then counted from the end of the string,
- length : (Optional) an an tinyint/smallint/integer/bigint value as the length of the substring.
Return Value:
- a string that represents the substring,
- missing if any argument is a missing value,
- null if any argument is a null value but no argument is a missing value, or if the substring could not be obtained because the starting offset is not within string bounds or length is negative.
- a type error will be raised if:
  - the first argument is any other non-string value,
  - or, the second argument is not a tinyint, smallint, integer, or bigint,
  - or, the third argument is not a tinyint, smallint, integer, or bigint if the argument is present.
Example:
```
substr("test string", 6, 3);
```
The expected result is:
```
"str"
```

The function has an alias substring.

trim

Syntax:
```
trim(string[, chars]);
```
Returns a new string with all leading characters that appear in chars removed. By default, white space is the character to trim.
Arguments:
- string : a string to be trimmed,
- chars : a string that contains characters that are used to trim.
Return Value:
- a trimmed, new string,
- missing if any argument is a missing value,
- null if any argument is a null value but no argument is a missing value,
- any other non-string input value will cause a type error.
Example:
```
trim("i like x-phone", "xphoen");
```
The expected result is:
```
" like "
```

upper

Syntax:
```
upper(string)
```
Converts a given string string to its uppercase form.
Arguments:
- string : a string to be converted.
Return Value:
- a string as the uppercase form of the given string,
- missing if the argument is a missing value,
- null if the argument is a null value,
- any other non-string input value will cause a type error.
Example:
```
upper("hello")
```
The expected result is:
```
"HELLO"
```

Temporal Functions

now_local (clock_local)

Syntax:
```
now_local([fmt])
```
The current time (at query compilation time) on the node that compiled the query, in the specified string format.
Arguments:
- fmt: A string, or an expression which evaluates to a string, representing a supported date format to use for the result.
  
  This argument is optional. If no format or an incorrect format is specified, it defaults to the combined full date and time.
Return Value:
- A date string in the format specified representing the local system time.

Example:

{"full_date":    now_local(),
 "invalid_date": now_local('invalid date'),
 "short_date":   now_local('1111-11-11')};

The expected result is:

{
  "full_date": "2018-09-07T14:16:35.233+01:00",
  "invalid_date": "2018-09-07T14:16:35.233+01:00",
  "short_date": "2018-09-07"
}

The function has an alias clock_local.

now_millis (clock_millis)

Syntax:
```
now_millis()
```
The current time (at query compilation time) on the node that compiled the query, as an Epoch/UNIX timestamp.
Arguments:

None.
Return Value:
- An integer representing the system time as Epoch/UNIX time in milliseconds.
Example:
```
{"CurrentTime": now_millis()};
```
The expected result is:
```
{
  "CurrentTime": 1536326726276
}
```

The function has an alias clock_millis.

now_str (clock_str)

Syntax:
```
now_str([fmt])
```
The current time (at query compilation time) on the node that compiled the query, in the specified string format.
Arguments:
- fmt: A string, or an expression which evaluates to a string, representing a supported date format to use for the result.
  
  This argument is optional. If no format or an incorrect format is specified, it defaults to the combined full date and time.
Return Value:
- A date string in the format specified representing the system time.

Example:

{"full_date":    now_str(),
 "invalid_date": now_str('invalid date'),
 "short_date":   now_str('1111-11-11')};

The expected result is:

{
  "full_date": "2018-09-07T14:26:01.115+01:00",
  "invalid_date": "2018-09-07T14:26:01.115+01:00",
  "short_date": "2018-09-07"
}

The function has an alias clock_str.

now_tz (clock_tz)

Syntax:
```
now_tz(tz [, fmt])
```
The current time (at query compilation time) in the timezone given by the timezone argument passed to the function. This time is the local system time converted to the specified timezone.

As this function converts the local time, it may not accurately represent the true time in that timezone.
Arguments:
- tz: A string, or an expression which evaluates to a string, representing the timezone to convert the local time to.
  
  If this argument is not a valid timezone then null is returned as the result.
- fmt: A string, or an expression which evaluates to a string, representing a supported date format to use for the result.
  
  This argument is optional. If no format or an incorrect format is specified, it defaults to the combined full date and time.
Return Value:
- An date string in the format specified representing the system time in the specified timezone.

Example:

{"UTC_full_date":    now_tz('UTC'),
 "UTC_short_date":   now_tz('UTC', '1111-11-11'),
 "invalid_timezone": now_tz('invalid timezone'),
 "us_east":          now_tz('US/Eastern'),
 "us_west":          now_tz('US/Pacific')};

The expected result is:

{
  "UTC_full_date": "2018-09-07T13:26:47.956Z",
  "UTC_short_date": "2018-09-07",
  "invalid_timezone": null,
  "us_east": "2018-09-07T09:26:47.956-04:00",
  "us_west": "2018-09-07T06:26:47.956-07:00"
}

The function has an alias clock_tz.

now_utc (clock_utc)

Syntax:
```
now_utc([fmt])
```
The current time in UTC. This time is the local system time converted to UTC. This function is provided for convenience and is the same as now_tz('UTC').
Arguments:
- fmt: A string, or an expression which evaluates to a string, representing a supported date format to use for the result.
  
  This argument is optional. If no format or an incorrect format is specified, it defaults to the combined full date and time.
Return Value:
- An date string in the format specified representing the system time in UTC.

Example:

{"full_date":  now_utc(),
 "short_date": now_utc('1111-11-11')};

The expected result is:

{
  "full_date": "2018-09-07T13:27:40.693Z",
  "short_date": "2018-09-07"
}

The function has an alias clock_utc.

date_add_millis

Syntax:
```
date_add_millis(date1, n, part)
```
Performs date arithmetic on a particular component of an Epoch/UNIX timestamp value. This calculation is specified by the arguments n and part. For example, a value of 3 for n and a value of day for part would add 3 days to the date specified by date1.
Arguments:
- date1: An integer, or an expression which evaluates to an integer, representing an Epoch/UNIX timestamp in milliseconds.
  
  If this argument is not an integer then null is returned.
- n: The value to increment the date component by. This value must be an integer, or an expression which evaluates to an integer, and may be negative to perform date subtraction.
  
  If a non-integer is passed to the function then null is returned.
- part: A string, or an expression which evaluates to a string, representing the component of the date to increment.
  
  If an invalid part is passed to the function then null is returned.
Return Value:
- An integer, representing the result of the calculation as an Epoch/UNIX timestamp in milliseconds.

Example:

{"add_3_days":  date_add_millis(1463284740000,  3, 'day'),
 "add_3_years": date_add_millis(1463284740000,  3, 'year'),
 "sub_3_days":  date_add_millis(1463284740000, -3, 'day'),
 "sub_3_years": date_add_millis(1463284740000, -3, 'year')};

The expected result is:

{
  "add_3_days": 1463543940000,
  "add_3_years": 1557892740000,
  "sub_3_days": 1463025540000,
  "sub_3_years": 1368590340000
}

date_add_str

Syntax:
```
date_add_str(date1, n, part)
```
Performs date arithmetic on a date string. This calculation is specified by the arguments n and part. For example a value of 3 for n and a value of day for part would add 3 days to the date specified by date1.
Arguments:
- date1: A string, or an expression which evaluates to a string, representing the date in a supported date format.
- n: The value to increment the date component by. This value must be an integer, or an expression which evaluates to an integer, and may be negative to perform date subtraction.
  
  If a non-integer is passed to the function then null is returned.
- part: A string, or an expression which evaluates to a string, representing the component of the date to increment.
  
  If an invalid part is passed to the function then null is returned.
Return Value:
- An integer representing the result of the calculation as an Epoch/UNIX timestamp in milliseconds.

Example:

{"add_3_days":  date_add_str('2016-05-15 03:59:00Z',  3, 'day'),
 "add_3_years": date_add_str('2016-05-15 03:59:00Z',  3, 'year'),
 "sub_3_days":  date_add_str('2016-05-15 03:59:00Z', -3, 'day'),
 "sub_3_years": date_add_str('2016-05-15 03:59:00Z', -3, 'year')};

The expected result is:

{
  "add_3_days": "2016-05-18T03:59:00Z",
  "add_3_years": "2019-05-15T03:59:00Z",
  "sub_3_days": "2016-05-12T03:59:00Z",
  "sub_3_years": "2013-05-15T03:59:00Z"
}

date_diff_millis

Syntax:
```
date_diff_millis(date1, date2, part)
```
Finds the elapsed time between two Epoch/UNIX timestamps. This elapsed time is measured from the date specified by date2 to the date specified by date1. If date1 is greater than date2, then the value returned is positive, otherwise the value returned is negative.
Arguments:
- date1: An integer, or an expression which evaluates to an integer, representing an Epoch/UNIX timestamp in milliseconds.
  
  If this argument is not an integer, then null is returned.
- date2: An integer, or an expression which evaluates to an integer, representing an Epoch/UNIX timestamp in milliseconds. This is the value that is subtracted from date1.
  
  If this argument is not an integer, then null is returned.
- part: A string, or an expression which evaluates to a string, representing the component of the date to increment.
  
  If an invalid part is passed to the function, then null is returned.
Return Value:
- An integer representing the elapsed time (based on the specified part) between both dates.

Example:

{"add_3_days":  date_diff_millis(1463543940000, 1463284740000, 'day'),
 "add_3_years": date_diff_millis(1557892740000, 1463284740000, 'year'),
 "sub_3_days":  date_diff_millis(1463025540000, 1463284740000, 'day'),
 "sub_3_years": date_diff_millis(1368590340000, 1463284740000, 'year')};

The expected result is:

{
  "add_3_days": 3,
  "add_3_years": 3,
  "sub_3_days": -3,
  "sub_3_years": -3
}

date_diff_str

Syntax:
```
date_diff_str(date1, date2, part)
```
Finds the elapsed time between two dates specified as formatted strings. This elapsed time is measured from the date specified by date2 to the date specified by date1. If date1 is greater than date2 then the value returned is positive, otherwise the value returned is negative.
Arguments:
- date1: An integer, or an expression which evaluates to an integer, representing an Epoch/UNIX timestamp in milliseconds. This is the value that is subtracted from date1.
  
  If this argument is not an integer, then null is returned.
- date2: An integer, or an expression which evaluates to an integer, representing an Epoch/UNIX timestamp in milliseconds. This is the value that is subtracted from date1.
  
  If this argument is not an integer, then null is returned.
- part: A string, or an expression which evaluates to a string, representing the component of the date to increment.
  
  If an invalid part is passed to the function, then null is returned.
Return Value:
- An integer representing the elapsed time (based on the specified part) between both dates.

Example:

{"add_3_days":  date_diff_str('2016-05-18T03:59:00Z', '2016-05-15 03:59:00Z', 'day'),
 "add_3_years": date_diff_str('2019-05-15T03:59:00Z', '2016-05-15 03:59:00Z', 'year'),
 "sub_3_days":  date_diff_str('2016-05-12T03:59:00Z', '2016-05-15 03:59:00Z', 'day'),
 "sub_3_years": date_diff_str('2013-05-15T03:59:00Z', '2016-05-15 03:59:00Z', 'year')};

The expected result is:

{
  "add_3_days": 3,
  "add_3_years": 3,
  "sub_3_days": -3,
  "sub_3_years": -3
}

date_format_str

Syntax:
```
date_format_str(date1, fmt)
```
Converts datetime strings from one supported date string format to a different supported date string format.
Arguments:
- date1: A string, or an expression which evaluates to a string, representing a date in a supported date format.
  
  If this argument is not a valid date string then null is returned.
- fmt: A string, or an expression which evaluates to a string, representing a supported date format to use for the result.
  
  If an incorrect format is specified, it defaults to the combined full date and time.
Return Value:
- A date string in the format specified.

Example:

{"full_to_short": date_format_str('2016-05-15T00:00:23+00:00', '1111-11-11'),
 "short_to_full": date_format_str('2016-05-15', '1111-11-11T00:00:00+00:00'),
 "time_to_full":  date_format_str('01:10:05', '1111-11-11T01:01:01Z')};

The expected result is:

{
  "full_to_short": "2016-05-15",
  "short_to_full": "2016-05-15T00:00:00+01:00",
  "time_to_full": "0000-01-01T01:10:05Z"
}

date_part_millis

Syntax:
```
date_part_millis(date1, part [, tz])
```
Extracts the value of a given date component from an Epoch/UNIX timestamp value.
Arguments:
- date1: An integer, or an expression which evaluates to an integer, representing an Epoch/UNIX timestamp in milliseconds. This is the value that is subtracted from date1.
  
  If this argument is not an integer, then null is returned.
- part: A string, or an expression which evaluates to a string, representing the component of the date to increment.
  
  If an invalid part is passed to the function, then null is returned.
- tz: A string, or an expression which evaluates to a string, representing the timezone to convert the local time to.
  
  This argument is optional. If not specified, it defaults to the system timezone. If an incorrect time zone is provided, then null is returned.
Return Value:
- An integer representing the value of the component extracted from the timestamp.

Example:

{"day_local": date_part_millis(1463284740000, 'day'),
 "day_pst":   date_part_millis(1463284740000, 'day', 'America/Tijuana'),
 "day_utc":   date_part_millis(1463284740000, 'day', 'UTC'),
 "month":     date_part_millis(1463284740000, 'month'),
 "week":      date_part_millis(1463284740000, 'week'),
 "year":      date_part_millis(1463284740000, 'year')};

The expected result is:

{
  "day_local": 15,
  "day_pst": 14,
  "day_utc": 15,
  "month": 5,
  "week": 20,
  "year": 2016
}

date_part_str

Syntax:
```
date_part_str(date1, part)
```
Extracts the value of a given date component from a date string.
Arguments:
- date1: An integer, or an expression which evaluates to an integer, representing an Epoch/UNIX timestamp in milliseconds. This is the value that is subtracted from date1.
  
  If this argument is not an integer, then null is returned.
- part: A string, or an expression which evaluates to a string, representing the component of the date to increment.
  
  If an invalid part is passed to the function, then null is returned.
Return Value:
- An integer representing the value of the component extracted from the timestamp.

Example:

{"day":         date_part_str('2016-05-15T03:59:00Z', 'day'),
 "millisecond": date_part_str('2016-05-15T03:59:00Z', 'millisecond'),
 "month":       date_part_str('2016-05-15T03:59:00Z', 'month'),
 "week":        date_part_str('2016-05-15T03:59:00Z', 'week'),
 "year":        date_part_str('2016-05-15T03:59:00Z', 'year')};

The expected result is:

{
  "day": 15,
  "millisecond": 0,
  "month": 5,
  "week": 20,
  "year": 2016
}

date_range_millis

Syntax:

date_range_millis(date1, date2, part [,n])

Generates an array of dates from the start date specified by date1 and the end date specified by date2, as Epoch/UNIX timestamps. The difference between each subsequent generated date can be adjusted.

It is possible to generate very large arrays using this function. In some cases the query engine may be unable to process all of these and cause excessive resource consumption. It is therefore recommended that you first validate the inputs to this function to ensure that the generated result is a reasonable size.

If the start date is greater than the end date passed to the function then an error is not thrown, but the result array is empty. An array of descending dates can be generated by setting the start date greater than the end date and specifying a negative value for n.
Arguments:
- date1: An integer, or an expression which evaluates to an integer, representing an Epoch/UNIX timestamp in milliseconds. This is the value that is subtracted from date1.
  
  If this argument is not an integer, then null is returned.
- date2: An integer, or an expression which evaluates to an integer, representing an Epoch/UNIX timestamp in milliseconds. This is the value that is subtracted from date1.
  
  If this argument is not an integer, then null is returned.
- part: A string, or an expression which evaluates to a string, representing the component of the date to increment.
  
  If an invalid part is passed to the function, then null is returned.
- n: An integer, or an expression which evaluates to an integer, representing the value by which to increment the part component for each generated date.
  
  This argument is optional. If not specified, it defaults to 1. If a value which is not an integer is specified, then null is returned.
Return Value:
- An array of integers representing the generated dates, as Epoch/UNIX timestamps, between date1 and date2.

Example:

{"range_of_milliseconds_by_month":          date_range_millis(1480752000000, 1475478000000, 'month', -1),
 "range_of_milliseconds_by_previous_month": date_range_millis(1480752000000, 1449129600000, 'month', -1)};

The expected result is:

{
  "range_of_milliseconds_by_month": [
    1480752000000,
    1478160000000
  ],
  "range_of_milliseconds_by_previous_month": [
    1480752000000,
    1478160000000,
    1475478000000,
    1472886000000,
    1470207600000,
    1467529200000,
    1464937200000,
    1462258800000,
    1459666800000,
    1456992000000,
    1454486400000,
    1451808000000
  ]
}

date_range_str

Syntax:

date_range_str(start_date, end_date, date_interval [, quantity_int ])

Generates an array of date strings between the start date and end date, calculated by the interval and quantity values. The input dates can be in any of the supported date formats.

It is possible to generate very large arrays using this function. In some cases the query engine may be unable to process all of these and cause excessive resource consumption. It is therefore recommended that you first validate the inputs of this function to ensure that the generated result is a reasonable size.

If the start_date is greater than the end_date, an error is not thrown, but the result array is empty. An array of descending dates can be generated by setting the start_date greater than the end_date and specifying a negative value for quantity_number.

Both specified dates must have the same string format, otherwise null is returned. To ensure that both dates have the same format, you should use date_format_str().
Arguments:
- start_date: A string, or an expression which evaluates to a string, representing a date in a supported date format. This is the date used as the start date of the array generation.
  
  If this argument is not an integer, then null is returned.
- end_date: A string, or an expression which evaluates to a string, representing a date in a supported date format. This is the date used as the end date of the array generation. This value is exclusive, that is, the end date is not included in the result.
  
  If this argument is not an integer, then null is returned.
- date_interval: A string, or an expression which evaluates to a string, representing the component of the date to increment.
  
  If an invalid part is passed to the function, then null is returned.
- quantity_int: An integer, or an expression which evaluates to an integer, representing the value by which to increment the interval component for each generated date.
  
  This argument is optional. If not specified, it defaults to 1. If a value which is not an integer is specified, then null is returned.
Return Value:
- An array of strings representing the generated dates, as date strings, between start_date and end_date.

Example:

{"ranges_by_quarters":      date_range_str('2015-11-30T15:04:05.999', '2017-04-14T15:04:06.998', 'quarter'),
 "ranges_by_single_day":    date_range_str('2016-01-01T15:04:05.999', '2016-01-05T15:04:05.998', 'day', 1),
 "ranges_by_four_months":   date_range_str('2018-01-01','2019-01-01', 'month', 4),
 "ranges_by_previous_days": date_range_str('2016-01-05T15:04:05.999', '2016-01-01T15:04:06.998', 'day', -1),
 "ranges_by_month":         date_range_str('2015-01-01T01:01:01', '2015-12-11T00:00:00', 'month', 1)};

The expected result is:

{
  "ranges_by_quarters": [
    "2015-11-30T15:04:05.999",
    "2016-02-29T15:04:05.999",
    "2016-05-29T15:04:05.999",
    "2016-08-29T15:04:05.999",
    "2016-11-29T15:04:05.999",
    "2017-02-28T15:04:05.999"
  ],
  "ranges_by_single_day": [
    "2016-01-01T15:04:05.999",
    "2016-01-02T15:04:05.999",
    "2016-01-03T15:04:05.999",
    "2016-01-04T15:04:05.999"
  ],
  "ranges_by_four_months": [
    "2018-01-01",
    "2018-05-01",
    "2018-09-01"
  ],
  "ranges_by_previous_days": [
    "2016-01-05T15:04:05.999",
    "2016-01-04T15:04:05.999",
    "2016-01-03T15:04:05.999",
    "2016-01-02T15:04:05.999"
  ],
  "ranges_by_month": [
    "2015-01-01T01:01:01",
    "2015-02-01T01:01:01",
    "2015-03-01T01:01:01",
    "2015-04-01T01:01:01",
    "2015-05-01T01:01:01",
    "2015-06-01T01:01:01",
    "2015-07-01T01:01:01",
    "2015-08-01T01:01:01",
    "2015-09-01T01:01:01",
    "2015-10-01T01:01:01",
    "2015-11-01T01:01:01",
    "2015-12-01T01:01:01"
  ]
}

date_trunc_millis

Syntax:
```
date_trunc_millis(date1, part)
```
Truncates an Epoch/UNIX timestamp up to the specified date component.
Arguments:
- date1: An integer, or an expression which evaluates to an integer, representing an Epoch/UNIX timestamp in milliseconds. This is the date used as the date to truncate.
  
  If this argument is not an integer, then null is returned.
- part: A string, or an expression which evaluates to a string, representing the component to truncate to.
  
  If an invalid part is specified, then null is returned.
Return Value:
- An integer representing the truncated timestamp in Epoch/UNIX time.

Example:

{"day":   date_trunc_millis(1463284740000, 'day'),
 "month": date_trunc_millis(1463284740000, 'month'),
 "year":  date_trunc_millis(1463284740000, 'year')};

The expected result is:

{
  "day": 1463270400000,
  "month": 1462060800000,
  "year": 1451606400000
}

date_trunc_str

Syntax:
```
date_trunc_str(date1, part)
```
Truncates a date string up to the specified date component.
Arguments:
- date1: A string, or an expression which evaluates to a string, representing a date in a supported date format. This is the date that is truncated.
  
  If this argument is not a valid date format, then null is returned.
- part: A string, or an expression which evaluates to a string, representing the component to truncate to.
  
  If an invalid part is specified, then null is returned.
Return Value:
- A date string representing the truncated date.

Example:

{"day":   date_trunc_str('2016-05-18T03:59:00Z', 'day'),
 "month": date_trunc_str('2016-05-18T03:59:00Z', 'month'),
 "year":  date_trunc_str('2016-05-18T03:59:00Z', 'year')};

The expected result is:

{
  "day": "2016-05-18T00:00:00Z",
  "month": "2016-05-01T00:00:00Z",
  "year": "2016-01-01T00:00:00Z"
}

duration_to_str

Syntax:
```
duration_to_str(duration)
```
Converts a number into a human-readable time duration with units.
Arguments:
- duration: A number, or an expression which evaluates to a number, which represents the duration to convert to a string. This value is specified in nanoseconds (1×10^-9 seconds).
  
  If a value which is not a number is specified, then null is returned.
Return Value:
- A string representing the human-readable duration.

Example:

{"microsecs": duration_to_str(2000),
 "millisecs": duration_to_str(2000000),
 "secs":      duration_to_str(2000000000)};

The expected result is:

{
  "microsecs": "2µs",
  "millisecs": "2ms",
  "secs": "2s"
}

millis

Syntax:
```
millis(date1)
```
Converts a date string to Epoch/UNIX milliseconds.
Arguments:
- date1: A string, or an expression which evaluates to a string, representing a date in a supported date format. This is the date to convert to Epoch/UNIX milliseconds.
  
  If this argument is not a valid date format. then null is returned.
Return Value:
- An integer representing the date string converted to Epoch/UNIX milliseconds.

Example:

{"DateStringInMilliseconds": millis("2016-05-15T03:59:00Z")};

The expected result is:

{
  "DateStringInMilliseconds": 1463284740000
}

millis_to_str (millis_to_local)

Syntax:
```
millis_to_str(date1 [, fmt ])
```
Converts an Epoch/UNIX timestamp into the specified date string format.
Arguments:
- date1: An integer, or an expression which evaluates to an integer, representing an Epoch/UNIX timestamp in milliseconds. This is the date to convert.
  If this argument is not an integer, then `null` is returned.
- fmt: A string, or an expression which evaluates to a string, representing a supported date format to use for the result.
  
  This argument is optional. If no format or an incorrect format is specified, it defaults to the combined full date and time.
Return Value:
- A date string representing the local date in the specified format.

Example:

{"full_date":      millis_to_str(1463284740000),
 "invalid_format": millis_to_str(1463284740000, 'invalid format'),
 "short_date":     millis_to_str(1463284740000, '1111-11-11')};

The expected result is:

{
  "full_date": "2016-05-15T04:59:00+01:00",
  "invalid_format": "2016-05-15T04:59:00+01:00",
  "short_date": "2016-05-15"
}

The function has an alias millis_to_local.

millis_to_tz (millis_to_zone_name)

Syntax:
```
millis_to_tz(date1, tz [, fmt])
```
Converts an Epoch/UNIX timestamp into the specified time zone in the specified date string format.
Arguments:
- date1: An integer, or an expression which evaluates to an integer, representing an Epoch/UNIX timestamp in milliseconds. This is the date to convert.
  
  If this argument is not an integer, then null is returned.
- tz: A string, or an expression which evaluates to a string, representing the timezone to convert the local time to.
  
  This argument is optional. If not specified, it defaults to the system timezone.
  
  If an incorrect time zone is provided, then null is returned.
- fmt: A string, or an expression which evaluates to a string, representing a supported date format to use for the result.
  
  This argument is optional. If no format or an incorrect format is specified, it defaults to the combined full date and time.
Return Value:
- A date string representing the date in the specified timezone in the specified format.

Example:

{"est": millis_to_tz(1463284740000, 'America/New_York'),
 "ist": millis_to_tz(1463284740000, 'Asia/Kolkata'),
 "utc": millis_to_tz(1463284740000, 'UTC')};

The expected result is:

{
  "est": "2016-05-14T23:59:00-04:00",
  "ist": "2016-05-15T09:29:00+05:30",
  "utc": "2016-05-15T03:59:00Z"
}

The function has an alias millis_to_zone_name.

millis_to_utc

Syntax:
```
millis_to_utc(date1 [, fmt])
```
Converts an Epoch/UNIX timestamp into local time in the specified date string format.
Arguments:
- date1: An integer, or an expression which evaluates to an integer, representing an Epoch/UNIX timestamp in milliseconds. This is the date to convert to UTC.
  
  If this argument is not an integer, then null is returned.
- fmt: A string, or an expression which evaluates to a string, representing a supported date format to use for the result.
  
  This argument is optional. If no format or an incorrect format is specified, it defaults to the combined full date and time.
Return Value:
- A date string representing the date in UTC in the specified format.

Example:

{"full_date":      millis_to_utc(1463284740000),
 "invalid_format": millis_to_utc(1463284740000, 'invalid format'),
 "short_date":     millis_to_utc(1463284740000, '1111-11-11')};

The expected result is:

{
  "full_date": "2016-05-15T03:59:00Z",
  "invalid_format": "2016-05-15T03:59:00Z",
  "short_date": "2016-05-15"
}

str_to_duration

Syntax:
```
str_to_duration(duration)
```
Converts a string representation of a time duration into nanoseconds. This accepts the following units:
- nanoseconds (ns)
- microseconds (us or µs)
- milliseconds (ms)
- seconds (s)
- minutes (m)
- hours (h)
Arguments:
- duration: A string, or an expression which evaluates to a string, representing the duration to convert.
  
  If an invalid duration string is specified, then null is returned.
Return Value:
- A single integer representing the duration in nanoseconds.

Example:

{"hour":        str_to_duration('1h'),
 "microsecond": str_to_duration('1us'),
 "millisecond": str_to_duration('1ms'),
 "minute":      str_to_duration('1m'),
 "nanosecond":  str_to_duration('1ns'),
 "second":      str_to_duration('1s')};

The expected result is:

{
  "hour": 3600000000000,
  "microsecond": 1000,
  "millisecond": 1000000,
  "minute": 60000000000,
  "nanosecond": 1,
  "second": 1000000000
}

str_to_millis

Syntax:
```
str_to_millis(date1)
```
Converts a date string to Epoch/UNIX milliseconds.
Arguments:
- date1: A string, or an expression which evaluates to a string, representing a date in a supported date format. This is the date to convert to Epoch/UNIX milliseconds.
  
  If this argument is not a valid date format, then null is returned.
Return Value:
- An integer representing the date string converted to Epoch/UNIX milliseconds.

Example:

{"Milliseconds": str_to_millis("2016-05-15T03:59:00Z")};

The expected result is:
```
{
  "Milliseconds": 1463284740000
}
```

str_to_utc

Syntax:
```
str_to_utc(date1)
```
Converts a date string into the equivalent date in UTC. The output date format follows the date format of the date passed as input.
Arguments:
- date1: A string, or an expression which evaluates to a string, representing a date in a supported date format. This is the date to convert to UTC.
  
  If this argument is not a valid date format, then null is returned.
Return Value:
- A single date string representing the date string converted to UTC.

Example:

{"full_date":  str_to_utc('1111-11-11T00:00:00+08:00'),
 "short_date": str_to_utc('1111-11-11')};

The expected result is:

{
  "full_date": "1111-11-10T16:00:00Z",
  "short_date": "1111-11-11"
}

str_to_tz (str_to_zone_name)

Syntax:
```
str_to_tz(date1, tz)
```
Converts a date string to its equivalent in the specified timezone. The output date format follows the date format of the date passed as input.
Arguments:
- date1: A string, or an expression which evaluates to a string, representing a date in a supported date format. This is the date to convert to UTC.
  
  If this argument is not a valid date format then null is returned.
- tz: A string, or an expression which evaluates to a string, representing the timezone to convert the local time to.
  
  If this argument is not a valid timezone, then null is returned.
Return Value:
- A single date string representing the date string converted to the specified timezone.

Example:

{"est":       str_to_tz('1111-11-11T00:00:00+08:00', 'America/New_York'),
 "utc":       str_to_tz('1111-11-11T00:00:00+08:00', 'UTC'),
 "utc_short": str_to_tz('1111-11-11', 'UTC')};

The expected result is:

{
  "est": "1111-11-10T11:00:00-05:00",
  "utc": "1111-11-10T16:00:00Z",
  "utc_short": "1111-11-11"
}

The function has an alias str_to_zone_name.

weekday_millis

Syntax:
```
weekday_millis(expr [, tz ])
```
Converts a date string to its equivalent in the specified timezone. The output date format follows the date format of the date passed as input.
Arguments:
- expr: An integer, or an expression which evaluates to an integer, representing an Epoch/UNIX timestamp in milliseconds.
- tz: A string, or an expression which evaluates to a string, representing the timezone for the expr argument.
  
  This argument is optional. If not specified, it defaults to the system timezone. If an incorrect time zone is provided then null is returned.
Return Value:
- A single date string representing the date string converted to the specified timezone.

Example:

{"Day": weekday_millis(1486237655742, 'America/Tijuana')};

The expected result is:
```
{
  "Day": "Saturday"
}
```

weekday_str

Syntax:
```
weekday_str(date)
```
Returns the day of the week string value from the input date string. Returns the weekday name from the input date in Unix timestamp. Note that his function returns the string value of the day of the week, whereas date_part_str() with part = "dow" returns an integer value of the weekday (0-6).
Arguments:
- date: A string, or an expression which evaluates to a string, representing a date in a supported date format. This is the date to convert to UTC.
  
  If this argument is not a valid date format then null is returned.
Return Value:
- The text string name of the day of the week, such as "Monday" or "Friday".
Example:
```
{"Day": weekday_str('2017-02-05')};
```
The expected result is:
```
{
  "Day": "Sunday"
}
```

Object Functions

object_add

Syntax:

object_add(object, new_attr_key, new_attr_value)

Adds a new field (name-value pair) to a given object. Note that this function does not update an existing field in a given object.
Arguments:
- object: An object, or an expression that evaluates to an object.
- new_attr_key: A string, or an expression which evaluates to a string, representing a field name.
- new_attr_value: A value, or any expression which evaluates to a value.
Return Value:
- The original JSON object, also including the added field.
- If you add a duplicate field (that is, if the name is found), this function returns the object unmodified.
- If new_attr_key is NULL, it returns a NULL value.
- If new_attr_key is MISSING, it returns a MISSING value.
- If new_attr_value is MISSING, it returns the object unmodified.
- If object is not an object, or NULL, it returns a NULL value object.
Example:
```
object_add({"a": 1}, "b", 2);
```
The expected result is:
```
{
  "a": 1,
  "b": 2
}
```

object_concat

Syntax:
```
object_concat(obj1, obj2 ...)
```
Concatenates the input objects. This function requires a minimum of two input objects.
Arguments:
- obj1, obj2 …: Objects, or expressions that evaluate to objects.
Return Value:
- A concatenated JSON object.

Example:

object_concat({"abc":1},{"def":2},{"ghi":3});

The expected result is:
```
{
  "ghi": 3,
  "def": 2,
  "abc": 1
}
```

object_length

Syntax:
```
object_length(object)
```
Counts the number of fields (name-value pairs) in an object.
Arguments:
- object: An object, or an expression that evaluates to an object.
Return Value:
- The number of fields in the object.

Example:

object_length({"abc":1, "def":2, "ghi":3});

The expected result is:
```
3
```

object_names

Syntax:
```
object_names(object)
```
Returns the names of all fields (name-value pairs) in an object.
Arguments:
- object: An object, or an expression that evaluates to an object.
Return Value:
- An array containing the field names of the object.
Example:
```
object_names({"a":1, "b":2, "c":3});
```
The expected result is:
```
[
  "a",
  "b",
  "c"
]
```

object_pairs

Syntax:
```
object_pairs(object)
```
Returns the names and values of all fields (name-value pairs) in an object.
Arguments:
- object: An object, or an expression that evaluates to an object.
Return Value:
- An array of objects, each of which contains the name and value of one field in the original object.

Example:

object_pairs({"abc":1, "def":2, "ghi":3});

The expected result is:

[
  {
    "name": "abc",
    "value": 1
  },
  {
    "name": "def",
    "value": 2
  },
  {
    "name": "ghi",
    "value": 3
  }
]

object_put

Syntax:

object_put(object, attr_key, attr_value)

Adds a new field (name-value pair), or updates an existing field in a given object.
Arguments:
- object: An object, or an expression that evaluates to an object.
- attr_key: A string, or an expression which evaluates to a string, representing a field name.
- attr_value: A value, or any expression which evaluates to a value.
Return Value:
- The original JSON object, also including the field.
- If attr_key is found in the object, this function replaces the corresponding field value by attr_value.
- If attr_key is MISSING, it returns a MISSING value.
- If attr_key is not a string, it returns a NULL value.
- If attr_value is MISSING, it deletes the corresponding existing field (if any), like object_remove().
Example:
```
object_put({"a": 1, "b": 2}, "a", 3);
```
The expected result is:
```
{
  "a": 3,
  "b": 2
}
```

object_rename

Syntax:

object_rename(object, old_attr_key, new_attr_key)

Renames a field (name-value pair) in the JSON input object.
Arguments:
- object: Any JSON object, or N1QL expression that can evaluate to a JSON object.
- old_attr_key: A string, or an expression which evaluates to a string, representing the old (original) field name inside the JSON object.
- new_attr_key: A string, or an expression which evaluates to a string, representing the new field name to replace old_attr_key inside the JSON object.
Return Value:
- The JSON object object with the updated field name.
- If object is not an object, or is NULL, the function returns a NULL value.
- If old_attr_key or new_attr_key is not a string, or is NULL, the function returns a NULL value.
- If any argument is MISSING, the function returns a MISSING value.

Example:

object_rename({"name": 1}, "name", "new_name");

The expected result is:
```
{
  "new_name": 1
}
```

object_remove

Syntax:
```
object_remove(object, attr_key)
```
Removes the specified field (name-value pair) from the given object.
Arguments:
- object: An object, or an expression that evaluates to an object.
- attr_key: A string, or an expression which evaluates to a string, representing the name of the field to remove.
Return Value:
- The updated object.
- If object is NULL, or is not an object, the function returns a NULL value.
- If attr_key is NULL, or is not a string, the function returns a NULL value.
- If any argument is MISSING, the function returns a MISSING value.

Example:

object_remove({"abc": 1, "def": 2, "ghi": 3}, "def");

The expected result is:
```
{
  "abc": 1,
  "ghi": 3
}
```

object_replace

Syntax:

object_replace(object, old_attr_value, new_attr_value)

Replaces all occurrences of a value in the JSON input object.
Arguments:
- object: Any JSON object, or N1QL expression that can evaluate to a JSON object.
- old_attr_value: A value, or any expression which evaluates to a value, representing the old (original) value inside the JSON object.
- new_attr_value: A value, or any expression which evaluates to a value, representing the new value to replace old_attr_value inside the JSON object.
Return Value:
- The JSON object object with the new value.
- If object is not an object, the function returns a NULL value.
- If object or old_attr_value is NULL, the function returns a NULL value.
- If any argument is MISSING, the function returns a MISSING value.

Example:

object_replace({"abc": 1, "def": 2, "ghi": 3}, 3, "xyz");

The expected result is:

{
  "abc": 1,
  "def": 2,
  "ghi": "xyz"
}

object_unwrap

Syntax:
```
object_unwrap(object)
```
Enables you to unwrap the value from an object containing a single field (name-value pair).
Arguments:
- object: An object, or an expression that evaluates to an object, containing exactly one field.
Return Value:
- The value from the field.
- If the object is MISSING, this function returns MISSING.
- For all other cases, or if the object contains more than one field, it returns NULL.

Example:

{ "v1": object_unwrap({"name": "value"}),
  "v2": object_unwrap(MISSING),
  "v3": object_unwrap({"name": "value", "name2": "value2"}),
  "v4": object_unwrap("some_string") };

The expected result is:

{
  "v1": "value",
  "v3": null,
  "v4": null
}

object_values

Syntax:
```
object_values(object)
```
Returns the values from all the fields (name-value pairs) in the object.
Arguments:
- object: An object, or an expression that evaluates to an object.
Return Value:
- An array which contains the values from all the fields in the object.
- If the object is MISSING, this function returns MISSING.
- If the object is NULL or not an object, it returns NULL.

Example:

object_values({"abc":1, "def":2, "ghi":3});

The expected result is:
```
[
  1,
  2,
  3
]
```

Aggregate Functions (Array Functions)

This section contains detailed descriptions of each SQL++ aggregate function (i.e., array function). Note that as described in the SQL++ query reference documentation, standard SQL aggregate functions (e.g., MIN, MAX, SUM, COUNT, and AVG) are not real functions in SQL++ but just syntactic sugars over corresponding SQL++ builtin aggregate functions (e.g., ARRAY_MIN, ARRAY_MAX, ARRAY_SUM, ARRAY_COUNT, and ARRAY_AVG).

array_count

Syntax:
```
array_count(collection)
```
Gets the number of non-null and non-missing items in the given collection.
Arguments:
- collection could be:
  - an array or multiset to be counted,
  - or, a null value,
  - or, a missing value.
Return Value:
- a bigint value representing the number of non-null and non-missing items in the given collection,
- null is returned if the input is null or missing,
- any other non-array and non-multiset input value will cause an error.

Example:

array_count( ['hello', 'world', 1, 2, 3, null, missing] );

The expected result is:
```
5
```

array_avg

Syntax:
```
array_avg(num_collection)
```
Gets the average value of the non-null and non-missing numeric items in the given collection.
Arguments:
- num_collection could be:
  - an array or multiset containing numeric values, nulls or missings,
  - or, a null value,
  - or, a missing value.
Return Value:
- a double value representing the average of the non-null and non-missing numbers in the given collection,
- null is returned if the input is null or missing,
- null is returned if the given collection does not contain any non-null and non-missing items,
- any other non-array and non-multiset input value will cause a type error,
- any other non-numeric value in the input collection will cause a type error.
Example:
```
array_avg( [1.2, 2.3, 3.4, 0, null] );
```
The expected result is:
```
1.725
```

array_sum

Syntax:
```
array_sum(num_collection)
```
Gets the sum of non-null and non-missing items in the given collection.
Arguments:
- num_collection could be:
  - an array or multiset containing numeric values, nulls or missings,
  - or, a null value,
  - or, a missing value.
Return Value:
- the sum of the non-null and non-missing numbers in the given collection. The returning type is decided by the item type with the highest order in the numeric type promotion order (tinyint-> smallint->integer->bigint->float->double) among items.
- null is returned if the input is null or missing,
- null is returned if the given collection does not contain any non-null and non-missing items,
- any other non-array and non-multiset input value will cause a type error,
- any other non-numeric value in the input collection will cause a type error.

Example:

array_sum( [1.2, 2.3, 3.4, 0, null, missing] );

The expected result is:
```
6.9
```

array_sql_min

Syntax:
```
array_min(num_collection)
```
Gets the min value of non-null and non-missing comparable items in the given collection.
Arguments:
- num_collection could be:
  - an array or multiset,
  - or, a null value,
  - or, a missing value.
Return Value:
- the min value of non-null and non-missing values in the given collection. The returning type is decided by the item type with the highest order in the type promotion order (tinyint-> smallint->integer->bigint->float->double) among numeric items.
- null is returned if the input is null or missing,
- null is returned if the given collection does not contain any non-null and non-missing items,
- multiple incomparable items in the input array or multiset will cause a type error,
- any other non-array and non-multiset input value will cause a type error.

Example:

array_min( [1.2, 2.3, 3.4, 0, null, missing] );

The expected result is:
```
0.0
```

array_max

Syntax:
```
array_max(num_collection)
```
Gets the max value of the non-null and non-missing comparable items in the given collection.
Arguments:
- num_collection could be:
  - an array or multiset,
  - or, a null value,
  - or, a missing value.
Return Value:
- the max value of non-null and non-missing numbers in the given collection. The returning type is decided by the item type with the highest order in the type promotion order (tinyint-> smallint->integer->bigint->float->double) among numeric items.
- null is returned if the input is null or missing,
- null is returned if the given collection does not contain any non-null and non-missing items,
- multiple incomparable items in the input array or multiset will cause a type error,
- any other non-array and non-multiset input value will cause a type error.

Example:

array_max( [1.2, 2.3, 3.4, 0, null, missing] );

The expected result is:
```
3.4
```

strict_count

Syntax:
```
strict_count(collection)
```
Gets the number of items in the given collection.
Arguments:
- collection could be:
  - an array or multiset containing the items to be counted,
  - or a null value,
  - or a missing value.
Return Value:
- a bigint value representing the number of items in the given collection,
- null is returned if the input is null or missing.
Example:
```
strict_count( [1, 2, null, missing] );
```
The expected result is:
```
4
```

strict_avg

Syntax:
```
strict_avg(num_collection)
```
Gets the average value of the numeric items in the given collection.
Arguments:
- num_collection could be:
  - an array or multiset containing numeric values, nulls or missings,
  - or, a null value,
  - or, a missing value.
Return Value:
- a double value representing the average of the numbers in the given collection,
- null is returned if the input is null or missing,
- null is returned if there is a null or missing in the input collection,
- any other non-numeric value in the input collection will cause a type error.
Example:
```
strict_avg( [100, 200, 300] );
```
The expected result is:
```
[ 200.0 ]
```

strict_sum

Syntax:
```
strict_sum(num_collection)
```
Gets the sum of the items in the given collection.
Arguments:
- num_collection could be:
  - an array or multiset containing numeric values, nulls or missings,
  - or, a null value,
  - or, a missing value.
Return Value:
- the sum of the numbers in the given collection. The returning type is decided by the item type with the highest order in the numeric type promotion order (tinyint-> smallint->integer->bigint->float->double) among items.
- null is returned if the input is null or missing,
- null is returned if there is a null or missing in the input collection,
- any other non-numeric value in the input collection will cause a type error.
Example:
```
strict_sum( [100, 200, 300] );
```
The expected result is:
```
600
```

array_min

Syntax:
```
strict_min(num_collection)
```
Gets the min value of comparable items in the given collection.
Arguments:
- num_collection could be:
  - an array or multiset,
  - or, a null value,
  - or, a missing value.
Return Value:
- the min value of the given collection. The returning type is decided by the item type with the highest order in the type promotion order (tinyint-> smallint->integer->bigint->float->double) among numeric items.
- null is returned if the input is null or missing,
- null is returned if there is a null or missing in the input collection,
- multiple incomparable items in the input array or multiset will cause a type error,
- any other non-array and non-multiset input value will cause a type error.
Example:
```
strict_min( [10.2, 100, 5] );
```
The expected result is:
```
5.0
```

array_max

Syntax:
```
strict_max(num_collection)
```
Gets the max value of numeric items in the given collection.
Arguments:
- num_collection could be:
  - an array or multiset,
  - or, a null value,
  - or, a missing value.
Return Value:
- The max value of the given collection. The returning type is decided by the item type with the highest order in the type promotion order (tinyint-> smallint->integer->bigint->float->double) among numeric items.
- null is returned if the input is null or missing,
- null is returned if there is a null or missing in the input collection,
- multiple incomparable items in the input array or multiset will cause a type error,
- any other non-array and non-multiset input value will cause a type error.
Example:
```
strict_max( [10.2, 100, 5] );
```
The expected result is:
```
100.0
```

array_append

Syntax:
```
array_append(list, val1, val2, ...)
```
Appends the supplied values to the input array or multiset. Values can be NULL, meaning you can append NULLs.
Arguments:
- list: An array or multiset, or an expression that evaluates to an array or multiset.
- val1, val2 …: Values, or expressions that evaluate to values.
Return Value:
- Returns a new array or multiset.
- Returns MISSING if any argument is MISSING.
- Returns NULL if list is NULL, or is not an array or multiset.
Example:
```
array_append([1, 2, 3], "a", "z");
```
The expected result is:
```
[
  1,
  2,
  3,
  "a",
  "z"
]
```

array_concat

Syntax:
```
array_concat(list1, list2, ...)
```
Concatenates all the values from all the supplied arrays or multisets, in order, into a new array or multiset.
Arguments:
- list1, list2 …: Arrays or multisets, or expressions that evaluate to arrays or multisets.
Return Value:
- Returns a new array or multiset.
- Returns MISSING if any argument is MISSING.
- Returns NULL if any argument is NULL, or is not an array or multiset.
- Returns an error if the input arguments are not all the same type — they must be all multisets or all arrays.

Example:

array_concat([1, 2, 3], ["a", "b", "c"]);

The expected result is:
```
[
  1,
  2,
  3,
  "a",
  "b",
  "c"
]
```

array_contains

Syntax:
```
array_contains(list, val)
```
Checks whether the the input array or multiset contains the value argument. A string value argument is case-sensitive.
Arguments:
- list: An array or multiset, or an expression that evaluates to an array or multiset.
- val: A value, or an expression that evaluates to a value.
Return Value:
- Returns true or false.
- Returns MISSING if any argument is MISSING.
- Returns NULL if any argument is NULL.
- Returns an error if val is an array, multiset, or object.
- Returns NULL if list is not an array.

Example:

{"v1": array_contains([1, 2, 3], 1),
 "v2": array_contains([1, 2, 3], "a")};

The expected result is:
```
{
  "v1": true,
  "v2": false
}
```

array_distinct

Syntax:
```
array_distinct(list)
```
Returns all distinct items from the input array or multiset. The list can contain NULL and MISSING items. NULL and MISSING are considered to be the same. String items are case-sensitive.
Arguments:
- list: An array or multiset, or an expression that evaluates to an array or multiset.
Return Value:
- Returns a new array if list is an array; returns a new multiset if list is a multiset.
- Returns MISSING if list is MISSING.
- Returns NULL if list is NULL, or is not an array or multiset.
- Returns an error if any item in list is itself an array, multiset, or object.

Example:

array_distinct([1, 2, null, 4, missing, 2, 1]);

The expected result is:
```
[
  1,
  2,
  null,
  4
]
```

array_flatten

Syntax:
```
array_flatten(list, depth)
```
Flattens any nested arrays or multisets up to the specified depth. If list is an array, the function returns an array; if list is a multiset, it returns a multiset. NULL and MISSING items are preserved. If depth is less than 0, the function flattens all nested arrays and multisets, no matter how deeply nested.
Arguments:
- list: An array or multiset, or an expression that evaluates to an array or multiset.
- depth: A number, or an expression that evaluates to a number.
Return Value:
- Returns a new array or multiset.
- Returns MISSING if any argument is MISSING.
- Returns NULL if any argument is NULL.
- Returns NULL if list is not an array or multiset.
- Returns NULL if depth is not numeric, or if it is not an integer value. (For example, 1.2 will produce NULL; 1.0 is OK.)

Example:

{"v1": array_flatten([2, null, [5, 6], 3, missing], 1),
 "v2": array_flatten([2, [5, 6], 3], 0)};

The expected result is:

{
  "v1": [
    2,
    null,
    5,
    6,
    3,
    null
  ],
  "v2": [
    2,
    [
      5,
      6
    ],
    3
  ]
}

where 0 depth does nothing.

array_ifnull

Syntax:
```
array_ifnull(list)
```
In an array, finds the first item that is not a NULL or MISSING. In a multiset, finds an item that is not a NULL or MISSING — which item is undefined.
Arguments:
- list: An array or multiset, or an expression that evaluates to an array or multiset.
Return Value:
- Returns the first non-NULL, non-MISSING item in an array, or any non-NULL, non-MISSING item in a multiset. If all items are NULL or MISSING, it returns NULL.
- Returns MISSING if the input array or multiset is MISSING.
- Returns NULL if list is NULL, or is not an array or multiset.
Example:
```
array_ifnull([null, 1, 2]);
```
The expected result is:
```
1
```

array_insert

Syntax:

array_insert(list, pos, val1, val2, ...)

Inserts the supplied values into the original array or multiset. Values can be NULL, meaning you can insert NULLs.

When the input is an array, the supplied values are inserted at the specified position. If the position is positive, the position before the first item is 0, the position before the second item is 1, and so on. If the position is negative, the position before the last item is -1, the position before the second-last item is -2, and so on. So for example, in the array [5,6], the valid positions are 0, 1, 2, -1, -2. If the input array or multiset is empty, the only valid position is 0. If the position is a floating-point number, it’s cast to integer.

When the input is a multiset, the location of the inserted values is undefined. The position must be less than the size of the multiset.
Arguments:
- list: An array or multiset, or an expression that evaluates to an array or multiset.
- pos: A number, or an expression that evaluates to a number.
- val1, val2 …: Values, or expressions that evaluate to values.
Return Value:
- Returns a new array or multiset.
- Returns MISSING if any argument is MISSING.
- Returns NULL if list is NULL, or is not an array or multiset.
- Returns NULL if pos is not numeric, or the position is out of bound, or if it is NaN or ±INF, or if it is not an integer value. (For example, 1.2 will produce NULL; 1.0 is OK.)

Example:

{"v1": array_insert([5, 6], 0, 7, 8),
 "v2": array_insert([5, 6], 1, 7, 8),
 "v3": array_insert([5, 6], 2, 7, 8),
 "v4": array_insert([5, 6], -1, 7, 8),
 "v5": array_insert([5, 6], -2, 7, 8)};

The expected result is:

{
  "v1": [
    7,
    8,
    5,
    6
  ],
  "v2": [
    5,
    7,
    8,
    6
  ],
  "v3": [
    5,
    6,
    7,
    8
  ],
  "v4": [
    5,
    7,
    8,
    6
  ],
  "v5": [
    7,
    8,
    5,
    6
  ]
}

array_intersect

Syntax:
```
array_intersect(list1, list2, ...)
```
Finds items that are present in all of the input arrays or multisets. NULL and MISSING items are ignored. String items are case-sensitive.
Arguments:
- list1, list2 …: Arrays or multisets, or expressions that evaluate to arrays or multisets.
Return Value:
- Returns a new array or multiset.
- Returns MISSING if any argument is MISSING.
- Returns NULL if any argument is NULL, or is not an array or multiset.
- Returns an error if the input arguments are not all the same type — they must be all multisets or all arrays.
- Returns an error if any item in an input array or multiset is itself an array, multiset, or object.

Example:

array_intersect([null, 2, missing], [3, missing, 2, null]);

The expected result is:
```
[
  2
]
```

array_position

Syntax:
```
array_position(list, val)
```
If list is an array, this function returns the position of val in the array, where the first position is 0. If list is a multiset, the returned value is undefined. A string value argument is case-sensitive.
Arguments:
- list: An array or multiset, or an expression that evaluates to an array or multiset.
- val: A value, or an expression that evaluates to a value.
Return Value:
- Returns an integer giving the position of val in list, or -1 if val is not found.
- Returns MISSING if any argument is MISSING.
- Returns NULL if any argument is NULL.
- Returns an error if val is an array, multiset, or object.
- Returns NULL if list is not an array or multiset.
Example:
```
array_position([1, 2, 3, 4], 1);
```
The expected result is:
```
0
```

array_prepend

Syntax:
```
array_prepend(val1, val2, ..., list)
```
Prepends the supplied values to the input array or multiset. Values can be NULL, meaning NULL values are prepended in the output.
Arguments:
- val1, val2 …: Values, or expressions that evaluate to values.
- list: An array or multiset, or an expression that evaluates to an array or multiset.
Return Value:
- Returns a new array or multiset.
- Returns MISSING if any argument is MISSING.
- Returns NULL if list is NULL, or is not an array or multiset.
Example:
```
array_prepend("a", "z", [1, 2, 3]);
```
The expected result is:
```
[
  "a",
  "z",
  1,
  2,
  3
]
```

array_put

Syntax:
```
array_put(list, val1, val2, ...)
```
Appends each supplied value to the input array or multiset, as long as the input array or multiset does not already contain an item with that value. Values cannot be NULL, meaning you cannot append NULLs.
Arguments:
- list: An array or multiset, or an expression that evaluates to an array or multiset.
- val1, val2 …: Values, or expressions that evaluate to values.
Return Value:
- Returns a new array or multiset.
- Returns MISSING if any argument is MISSING.
- Returns NULL if any argument is NULL.
- Returns an error if any value argument is an array, multiset, or object.
Example:
```
array_put([2, 3], 2, 2, 9, 9);
```
The expected result is:
```
[
  2,
  3,
  9,
  9
]
```

array_range

Syntax:

array_range(start_num, end_num [, step_num])

Returns an array of numbers, starting at start_num and ending immediately before end_num. If specified, step_num determines the step between each number in the array; otherwise, the default step is 1. The function returns an empty array if it cannot determine a proper sequence with the arguments given.
Arguments:
- start_num: A number, or an expression that evaluates to a number.
- end_num: A number, or an expression that evaluates to a number.
- step_num: A number, or an expression that evaluates to a number.
Return Value:
- Returns a new array.
- Returns MISSING if any argument is MISSING.
- Returns NULL if any argument is NULL.
- Returns NULL if any argument is not numeric, or if it is NaN, or ±INF.

Example:

{"v1": array_range(1, 5),
 "v2": array_range(5, 1, -1),
 "v3": array_range(2, 20, -2),
 "v4": array_range(10, 3, 4),
 "v5": array_range(1, 6, 0)};

The expected result is:

{
  "v1": [
    1,
    2,
    3,
    4
  ],
  "v2": [
    5,
    4,
    3,
    2
  ],
  "v3": [],
  "v4": [],
  "v5": []
}

array_remove

Syntax:
```
array_remove(list, val1, val2, ...)
```
Removes all the supplied values from the input array or multiset. Values cannot be NULL, meaning you cannot remove NULLs. String value arguments are case-sensitive.
Arguments:
- list: An array or multiset, or an expression that evaluates to an array or multiset.
- val1, val2 …: Values, or expressions that evaluate to values.
Return Value:
- Returns a new array if list is an array; returns a new multiset if list is a multiset.
- Returns MISSING if any argument is MISSING.
- Returns NULL if any argument is NULL.
- Returns an error if any value argument is an array, multiset, or object.
Example:
```
array_remove([1, 2, 2, 3, 4], 2, 4);
```
The expected result is:
```
[
  1,
  3
]
```

array_repeat

Syntax:
```
array_repeat(val, num_times)
```
Returns an array containing the input value the specified number of times.
Arguments:
- val: A value, or an expression that evaluates to a value.
- num_times: A number, or an expression that evaluates to a number.
Return Value:
- Returns an array.
- Returns MISSING if any argument is MISSING.
- Returns NULL if any argument is NULL.
- Returns NULL if num_times is not numeric, or if it is negative, NaN or ±INF, or if it is not an integer value. (For example, 1.2 will produce NULL; 1.0 is OK.)
Example:
```
array_repeat("abc", 3);
```
The expected result is:
```
[
  "abc",
  "abc",
  "abc"
]
```

array_replace

Syntax:

array_replace(list, val1, val2 [, max_num_times])

Replaces each occurrence of val1 in the original array or multiset with val2. If you supply the optional max_num_times argument, the function replaces val1 the specified number of times. If max_num_times is negative, the function replaces all occurrences. The val2 argument can be NULL, meaning you can replace existing items with NULLs.
Arguments:
- list: An array or multiset, or an expression that evaluates to an array or multiset.
- val1: A value, or an expression that evaluates to a value.
- val2: A value, or an expression that evaluates to a value.
- max_num_times: A number, or an expression that evaluates to a number.
Return Value:
- Returns a new array or multiset.
- Returns MISSING if any argument is MISSING.
- Returns NULL if any argument is NULL, except for val2.
- Returns NULL if list is not an array or multiset.
- Returns NULL if num_times is not numeric, or if it is not an integer value. (For example, 1.2 will produce NULL; 1.0 is OK.)
- Returns an error if val1 is an array, multiset, or object.
Example:
```
array_replace([2,3,3,3,1], 3, 8, 2);
```
The expected result is:
```
[
  2,
  8,
  8,
  3,
  1
]
```

array_reverse

Syntax:
```
array_reverse(list)
```
If list is an array, this function returns an array with the order of items reversed. If list is a multiset, the function returns the same multiset unchanged. The list can contain NULL and MISSING items, and both are preserved.
Arguments:
- list: An array or multiset, or an expression that evaluates to an array or multiset.
Return Value:
- Returns a new array or multiset.
- Returns MISSING if list is MISSING.
- Returns NULL if list is NULL, or is not an array or multiset.
Example:
```
array_reverse([1, 2, 3, 4]);
```
The expected result is:
```
[
  4,
  3,
  2,
  1
]
```

array_sort

Syntax:
```
array_sort(list)
```
If list is an array, this function returns an array with items sorted in ascending order. If list is a multiset, the function returns the same multiset unchanged. The list can contain NULL and MISSING items, and both are preserved. String items are case-sensitive.
Arguments:
- list: An array or multiset, or an expression that evaluates to an array or multiset.
Return Value:
- Returns a new array or multiset.
- Returns MISSING if list is MISSING.
- Returns NULL if list is NULL, or is not an array or multiset.
- Returns an error if any item in list is itself an array, multiset, or object.

Example:

array_sort([1, "Z", "a", "A", "z", 0, null]);

The expected result is:

[
  null,
  0,
  1,
  "A",
  "Z",
  "a",
  "z"
]

array_star

Syntax:
```
array_star(ordered_list)
```
Takes an array of objects, such as [{"id":1, "dept":"CS"}, {"id":2, "dept":"FIN"}, {"id":3, "dept":"CS"}], and returns a new object summarizing the name-value pairs in the input array. In the returned object, the name of each item is taken from a name-value pair found in the input array, and the value of each item is an array of all the values associated with that name, taken from all objects in the input array.
Arguments:
- ordered_list: An array, or an expression that evaluates to an array.
Return Value:
- Returns a new object.
- Returns MISSING if ordered_list is MISSING.
- Returns NULL if ordered_list is NULL, or is not an array.
- Returns MISSING if ordered_list has no concept of fields — for example, if the input array contains no object items, such as a list of integers.

Example:

{"v1": array_star([{"a":1, "b":2}, {"a":9, "b":4}]),
 "v2": array_star([{"a":1}, {"a":9, "b":4}]),
 "v3": array_star([{"a":1, "c":5}, {"a":9, "b":4}]),
 "v4": array_star([{"c":5, "a":1}, "non_object"]),
 "v5": array_star(["non_object1", "non_object2"])};

The expected result is:

{
  "v1": {
    "a": [
      1,
      9
    ],
    "b": [
      2,
      4
    ]
  },
  "v2": {
    "a": [
      1,
      9
    ],
    "b": [
      null,
      4
    ]
  },
  "v3": {
    "a": [
      1,
      9
    ],
    "b": [
      null,
      4
    ],
    "c": [
      5,
      null
    ]
  },
  "v4": {
    "a": [
      1,
      null
    ],
    "c": [
      5,
      null
    ]
  }
}

where "v5" is MISSING.

In the output object, name-value pairs are ordered by their names, regardless of their original order within the object items in the input array. So in example 4, in the output object, the pair named "a" comes before the pair named "c". However, in the output object, the items within each array are not ordered: they appear in the sequence in which they are found in the input array. So in example 1, the pair named "a" has the value [1, 9]; the first item in the output array (which is 1) is taken from the first object in the input array, and so on.

array_symdiff

Syntax:
```
array_symdiff(list1, list2, ...)
```
Returns the set symmetric difference, or disjunctive union, of the input arrays or multisets. The output contains only those items that appear in exactly one of the input arrays or multisets.
Arguments:
- list1, list2 …: Arrays or multisets, or expressions that evaluate to arrays or multisets.
Return Value:
- Returns a new array or multiset.
- Returns MISSING if any argument is MISSING.
- Returns NULL if any argument is NULL, or is not an array or multiset.
- Returns an error if the input arguments are not all the same type — they must be all multisets or all arrays.
- Returns an error if any item in an input array or multiset is itself an array, multiset, or object.

Example:

array_symdiff([1, 2], [1, 2, 4], [1, 3]);

The expected result is:
```
[
  4,
  3
]
```

array_symdiffn

Syntax:
```
array_symdiffn(list1, list2, ...)
```
Returns a new array or multiset based on the set symmetric difference, or disjunctive union, of the input arrays. The new array or multiset contains only those items that appear in an odd number of input arrays.
Arguments:
- list1, list2 …: Arrays or multisets, or expressions that evaluate to arrays or multisets.
Return Value:
- Returns a new array or multiset.
- Returns MISSING if any argument is MISSING.
- Returns NULL if any argument is NULL, or is not an array or multiset.
- Returns an error if the input arguments are not all the same type — they must be all multisets or all arrays.
- Returns an error if any item in an input array or multiset is itself an array, multiset, or object.

Example:

array_symdiffn([1, 2], [1, 2, 4], [1, 3]);

The expected result is:
```
[
  1,
  4,
  3
]
```

Refer to the following article for more information on the difference between a normal and n-ary symdiff: https://en.wikipedia.org/wiki/Symmetric_difference.

array_union

Syntax:
```
array_union(list1, list2, ...)
```
Returns the set union of the input arrays (no duplicates).
Arguments:
- list1, list2 …: Arrays or multisets, or expressions that evaluate to arrays or multisets.
Return Value:
- Returns a new array or multiset.
- Returns MISSING if any argument is MISSING.
- Returns NULL if any argument is NULL, or is not an array or multiset.
- Returns an error if the input arguments are not all the same type — they must be all multisets or all arrays.
- Returns an error if any item in an input array or multiset is itself an array, multiset, or object.
Example:
```
array_union([1, 2], [1, 2, 4], [1, 3]);
```
The expected result is:
```
[
  1,
  2,
  4,
  3
]
```

Comparison Functions

greatest

Syntax:

greatest(numeric_value1, numeric_value2, ...)

Computes the greatest value among arguments.
Arguments:
- numeric_value1: a tinyint/smallint/integer/bigint/float/double value,
- numeric_value2: a tinyint/smallint/integer/bigint/float/double value,
- ….
Return Value:
- the greatest values among arguments. The returning type is decided by the item type with the highest order in the numeric type promotion order (tinyint-> smallint->integer->bigint->float->double) among items.
- null if any argument is a missing value or null value,
- any other non-numeric input value will cause a type error.

Example:

{ "v1": greatest(1, 2, 3), "v2": greatest(float("0.5"), double("-0.5"), 5000) };

The expected result is:
```
{ "v1": 3, "v2": 5000.0 }
```

least

Syntax:

least(numeric_value1, numeric_value2, ...)

Computes the least value among arguments.
Arguments:
- numeric_value1: a tinyint/smallint/integer/bigint/float/double value,
- numeric_value2: a tinyint/smallint/integer/bigint/float/double value,
- ….
Return Value:
- the least values among arguments. The returning type is decided by the item type with the highest order in the numeric type promotion order (tinyint-> smallint->integer->bigint->float->double) among items.
- null if any argument is a missing value or null value,
- any other non-numeric input value will cause a type error.

Example:

{ "v1": least(1, 2, 3), "v2": least(float("0.5"), double("-0.5"), 5000) };

The expected result is:
```
{ "v1": 1, "v2": -0.5 }
```

Type Functions

is_array

Syntax:
```
is_array(expr)
```
Checks whether the given expression is evaluated to be an array value.
Arguments:
- expr : an expression (any type is allowed).
Return Value:
- a boolean on whether the argument is an array value or not,
- a missing if the argument is a missing value,
- a null if the argument is a null value.

Example:

{
  "a": is_array(true),
  "b": is_array(false),
  "c": isarray(null),
  "d": isarray(missing),
  "e": isarray("d"),
  "f": isarray(4.0),
  "g": isarray(5),
  "h": isarray(["1", 2]),
  "i": isarray({"a":1})
};

The expected result is:

{ "a": false, "b": false, "c": null, "e": false, "f": false, "g": false, "h": true, "i": false }

The function has an alias isarray.

is_atomic (is_atom)

Syntax:
```
is_atomic(expr)
```
Checks whether the given expression is evaluated to be a value of a primitive type.
Arguments:
- expr : an expression (any type is allowed).
Return Value:
- a boolean on whether the argument is a primitive type or not,
- a missing if the argument is a missing value,
- a null if the argument is a null value.

Example:

{
  "a": is_atomic(true),
  "b": is_atomic(false),
  "c": isatomic(null),
  "d": isatomic(missing),
  "e": isatomic("d"),
  "f": isatom(4.0),
  "g": isatom(5),
  "h": isatom(["1", 2]),
  "i": isatom({"a":1})
};

The expected result is:

{ "a": true, "b": true, "c": null, "e": true, "f": true, "g": true, "h": false, "i": false }

The function has three aliases: isatomic, is_atom, and isatom.

is_boolean (is_bool)

Syntax:
```
is_boolean(expr)
```
Checks whether the given expression is evaluated to be a boolean value.
Arguments:
- expr : an expression (any type is allowed).
Return Value:
- a boolean on whether the argument is a boolean value or not,
- a missing if the argument is a missing value,
- a null if the argument is a null value.

Example:

{
  "a": isboolean(true),
  "b": isboolean(false),
  "c": is_boolean(null),
  "d": is_boolean(missing),
  "e": isbool("d"),
  "f": isbool(4.0),
  "g": isbool(5),
  "h": isbool(["1", 2]),
  "i": isbool({"a":1})
};

The expected result is:

{ "a": true, "b": true, "c": null, "e": false, "f": false, "g": false, "h": false, "i": false }

The function has three aliases: isboolean, is_bool, and isbool.

is_number (is_num)

Syntax:
```
is_number(expr)
```
Checks whether the given expression is evaluated to be a numeric value.
Arguments:
- expr : an expression (any type is allowed).
Return Value:
- a boolean on whether the argument is a smallint/tinyint/integer/bigint/float/double value or not,
- a missing if the argument is a missing value,
- a null if the argument is a null value.

Example:

{
  "a": is_number(true),
  "b": is_number(false),
  "c": isnumber(null),
  "d": isnumber(missing),
  "e": isnumber("d"),
  "f": isnum(4.0),
  "g": isnum(5),
  "h": isnum(["1", 2]),
  "i": isnum({"a":1})
};

The expected result is:

{ "a": false, "b": false, "c": null, "e": false, "f": true, "g": true, "h": false, "i": false }

The function has three aliases: isnumber, is_num, and isnum.

is_object (is_obj)

Syntax:
```
is_object(expr)
```
Checks whether the given expression is evaluated to be a object value.
Arguments:
- expr : an expression (any type is allowed).
Return Value:
- a boolean on whether the argument is a object value or not,
- a missing if the argument is a missing value,
- a null if the argument is a null value.

Example:

{
  "a": is_object(true),
  "b": is_object(false),
  "c": isobject(null),
  "d": isobject(missing),
  "e": isobj("d"),
  "f": isobj(4.0),
  "g": isobj(5),
  "h": isobj(["1", 2]),
  "i": isobj({"a":1})
};

The expected result is:

{ "a": false, "b": false, "c": null, "e": false, "f": false, "g": false, "h": false, "i": true }

The function has three aliases: isobject, is_obj, and isobj.

is_string (is_str)

Syntax:
```
is_string(expr)
```
Checks whether the given expression is evaluated to be a string value.
Arguments:
- expr : an expression (any type is allowed).
Return Value:
- a boolean on whether the argument is a string value or not,
- a missing if the argument is a missing value,
- a null if the argument is a null value.

Example:

{
  "a": is_string(true),
  "b": isstring(false),
  "c": isstring(null),
  "d": isstr(missing),
  "e": isstr("d"),
  "f": isstr(4.0),
  "g": isstr(5),
  "h": isstr(["1", 2]),
  "i": isstr({"a":1})
};

The expected result is:

{ "a": false, "b": false, "c": null, "e": true, "f": false, "g": false, "h": false, "i": false }

The function has three aliases: isstring, is_str, and isstr.

is_null

Syntax:
```
is_null(expr)
```
Checks whether the given expression is evaluated to be a null value.
Arguments:
- expr : an expression (any type is allowed).
Return Value:
- a boolean on whether the variable is a null or not,
- a missing if the input is missing.

Example:

{ "v1": is_null(null), "v2": is_null(1), "v3": is_null(missing) };

The expected result is:
```
{ "v1": true, "v2": false }
```

The function has an alias isnull.

is_missing

Syntax:
```
is_missing(expr)
```
Checks whether the given expression is evaluated to be a missing value.
Arguments:
- expr : an expression (any type is allowed).
Return Value:
- a boolean on whether the variable is a missing or not.

Example:

{ "v1": is_missing(null), "v2": is_missing(1), "v3": is_missing(missing) };

The expected result is:

{ "v1": false, "v2": false, "v3": true }

The function has an alias ismissing.

is_unknown

Syntax:
```
is_unknown(expr)
```
Checks whether the given variable is a null value or a missing value.
Arguments:
- expr : an expression (any type is allowed).
Return Value:
- a boolean on whether the variable is a null/missing value (true) or not (`false).

Example:

{ "v1": is_unknown(null), "v2": is_unknown(1), "v3": is_unknown(missing) };

The expected result is:
```
{ "v1": true, "v2": false, "v3": true }
```

The function has an alias isunknown.

to_array

Syntax:
```
to_array(expr)
```
Converts input value to an array value
Arguments:
- expr : an expression
Return Value:
- if the argument is missing then missing is returned
- if the argument is null then null is returned
- if the argument is of array type then it is returned as is
- if the argument is of multiset type then it is returned as an array with elements in an undefined order
- otherwise an array containing the input expression as its single item is returned

Example:

{
  "v1": to_array("asterix"),
  "v2": to_array(["asterix"]),
};

The expected result is:

{ "v1": ["asterix"], "v2": ["asterix"] }

The function has an alias toarray.

to_atomic (to_atom)

Syntax:
```
to_atomic(expr)
```
Converts input value to a primitive value
Arguments:
- expr : an expression
Return Value:
- if the argument is missing then missing is returned
- if the argument is null then null is returned
- if the argument is of primitive type then it is returned as is
- if the argument is of array or multiset type and has only one element then the result of invoking to_atomic() on that element is returned
- if the argument is of object type and has only one field then the result of invoking to_atomic() on the value of that field is returned
- otherwise null is returned

Example:

{
  "v1": to_atomic("asterix"),
  "v2": to_atomic(["asterix"]),
  "v3": to_atomic([0, 1]),
  "v4": to_atomic({"value": "asterix"}),
  "v5": to_number({"x": 1, "y": 2})
};

The expected result is:

{ "v1": "asterix", "v2": "asterix", "v3": null, "v4": "asterix", "v5": null }

The function has three aliases: toatomic, to_atom, and toatom.

to_boolean (to_bool)

Syntax:
```
to_boolean(expr)
```
Converts input value to a boolean value
Arguments:
- expr : an expression
Return Value:
- if the argument is missing then missing is returned
- if the argument is null then null is returned
- if the argument is of boolean type then it is returned as is
- if the argument is of numeric type then false is returned if it is 0 or NaN, otherwise true
- if the argument is of string type then false is returned if it’s empty, otherwise true
- if the argument is of array or multiset type then false is returned if it’s size is 0, otherwise true
- if the argument is of object type then false is returned if it has no fields, otherwise true
- type error is raised for all other input types

Example:

{
  "v1": to_boolean(0),
  "v2": to_boolean(1),
  "v3": to_boolean(""),
  "v4": to_boolean("asterix")
};

The expected result is:

{ "v1": false, "v2": true, "v3": false, "v4": true }

The function has three aliases: toboolean, to_bool, and tobool.

to_bigint

Syntax:
```
to_bigint(expr)
```
Converts input value to an integer value
Arguments:
- expr : an expression
Return Value:
- if the argument is missing then missing is returned
- if the argument is null then null is returned
- if the argument is of boolean type then 1 is returned if it is true, 0 if it is false
- if the argument is of numeric integer type then it is returned as the same value of bigint type
- if the argument is of numeric float/double type then it is converted to bigint type
- if the argument is of string type and can be parsed as integer then that integer value is returned, otherwise null is returned
- if the argument is of array/multiset/object type then null is returned
- type error is raised for all other input types

Example:

{
  "v1": to_bigint(false),
  "v2": to_bigint(true),
  "v3": to_bigint(10),
  "v4": to_bigint(float("1e100")),
  "v5": to_bigint(double("1e1000")),
  "v6": to_bigint("20")
};

The expected result is:

{ "v1": 0, "v2": 1, "v3": 10, "v4": 9223372036854775807, "v5": 9223372036854775807, "v6": 20 }

The function has an alias tobigint.

to_double

Syntax:
```
to_double(expr)
```
Converts input value to a double value
Arguments:
- expr : an expression
Return Value:
- if the argument is missing then missing is returned
- if the argument is null then null is returned
- if the argument is of boolean type then 1.0 is returned if it is true, 0.0 if it is false
- if the argument is of numeric type then it is returned as the value of double type
- if the argument is of string type and can be parsed as double then that double value is returned, otherwise null is returned
- if the argument is of array/multiset/object type then null is returned
- type error is raised for all other input types

Example:

{
  "v1": to_double(false),
  "v2": to_double(true),
  "v3": to_double(10),
  "v4": to_double(11.5),
  "v5": to_double("12.5")
};

The expected result is:

{ "v1": 0.0, "v2": 1.0, "v3": 10.0, "v4": 11.5, "v5": 12.5 }

The function has an alias todouble.

to_number (to_num)

Syntax:
```
to_number(expr)
```
Converts input value to a numeric value
Arguments:
- expr : an expression
Return Value:
- if the argument is missing then missing is returned
- if the argument is null then null is returned
- if the argument is of numeric type then it is returned as is
- if the argument is of boolean type then 1 is returned if it is true, 0 if it is false
- if the argument is of string type and can be parsed as bigint then that bigint value is returned, otherwise if it can be parsed as double then that double value is returned, otherwise null is returned
- if the argument is of array/multiset/object type then null is returned
- type error is raised for all other input types

Example:

{
  "v1": to_number(false),
  "v2": to_number(true),
  "v3": to_number(10),
  "v4": to_number(11.5),
  "v5": to_number("12.5")
};

The expected result is:

{ "v1": 0, "v2": 1, "v3": 10, "v4": 11.5, "v5": 12.5 }

The function has three aliases: tonumber, to_num, and tonum.

to_object (to_obj)

Syntax:
```
to_object(expr)
```
Converts input value to an object value
Arguments:
- expr : an expression
Return Value:
- if the argument is missing then missing is returned
- if the argument is null then null is returned
- if the argument is of object type then it is returned as is
- otherwise an empty object is returned

Example:

{
  "v1": to_object({"value": "asterix"}),
  "v2": to_object("asterix")
};

The expected result is:

{ "v1": {"value": "asterix"}, "v2": {} }

The function has three aliases: toobject, to_obj, and toobj.

to_string (to_str)

Syntax:
```
to_string(expr)
```
Converts input value to a string value
Arguments:
- expr : an expression
Return Value:
- if the argument is missing then missing is returned
- if the argument is null then null is returned
- if the argument is of boolean type then "true" is returned if it is true, "false" if it is false
- if the argument is of numeric type then its string representation is returned
- if the argument is of string type then it is returned as is
- if the argument is of array/multiset/object type then null is returned
- type error is raised for all other input types

Example:

{
  "v1": to_string(false),
  "v2": to_string(true),
  "v3": to_string(10),
  "v4": to_string(11.5),
  "v5": to_string("asterix")
};

The expected result is:

{ "v1": "false", "v2": "true", "v3": "10", "v4": "11.5", "v5": "asterix" }

The function has three aliases: tostring, to_str, and tostr.

typename

Syntax:
```
typename(expr)
```
Returns the type of an expression.
Arguments:
- expr: an expression.
Return Value:
- Returns a string, depending on the type of expr: number, string, array, object, or boolean.
- Returns NULL if expr is NULL.

Example:

{"v1": typename(123),
 "v2": typename("abc"),
 "v3": typename([1, 2, 3]),
 "v4": typename({"abc": 123}),
 "v5": typename(true)};

The expected result is:

{
  "v1": "number",
  "v2": "string",
  "v3": "array",
  "v4": "object",
  "v5": "boolean"
}

Conditional Functions

if_null (ifnull)

Syntax:

if_null(expression1, expression2, ... expressionN)

Finds first argument which value is not null and returns that value
Arguments:
- expressionI : an expression (any type is allowed).
Return Value:
- a null if all arguments evaluate to null or no arguments specified
- a value of the first non-null argument otherwise

Example:

{
    "a": if_null(),
    "b": if_null(null),
    "c": if_null(null, "analytics"),
    "d": is_missing(if_null(missing))
};

The expected result is:

{ "a": null, "b": null, "c": "analytics", "d": true }

The function has an alias ifnull.

if_missing (ifmissing)

Syntax:

if_missing(expression1, expression2, ... expressionN)

Finds first argument which value is not missing and returns that value
Arguments:
- expressionI : an expression (any type is allowed).
Return Value:
- a null if all arguments evaluate to missing or no arguments specified
- a value of the first non-missing argument otherwise

Example:

{
    "a": if_missing(),
    "b": if_missing(missing),
    "c": if_missing(missing, "analytics"),
    "d": if_missing(null, "analytics")
};

The expected result is:

{ "a": null, "b": null, "c": "analytics", "d": null }

The function has an alias ifmissing.

if_missing_or_null (ifmissingornull)

Syntax:

if_missing_or_null(expression1, expression2, ... expressionN)

Finds first argument which value is not null or missing and returns that value
Arguments:
- expressionI : an expression (any type is allowed).
Return Value:
- a null if all arguments evaluate to either null or missing, or no arguments specified
- a value of the first non-null, non-missing argument otherwise

Example:

{
    "a": if_missing_or_null(),
    "b": if_missing_or_null(null, missing),
    "c": if_missing_or_null(null, missing, "analytics")
};

The expected result is:

{ "a": null, "b": null, "c": "analytics" }

The function has an alias ifmissingornull.

if_inf (ifinf)

Syntax:

if_inf(expression1, expression2, ... expressionN)

Finds first argument which is a non-infinite (INF or-INF) number
Arguments:
- expressionI : an expression (any type is allowed).
Return Value:
- a missing if missing argument was encountered before the first non-infinite number argument
- a null if null argument or any other non-number argument was encountered before the first non-infinite number argument
- the first non-infinite number argument otherwise

Example:

{
    "a": is_null(if_inf(null)),
    "b": is_missing(if_inf(missing)),
    "c": is_null(if_inf(double("INF"))),
    "d": if_inf(1, null, missing) ],
    "e": is_null(if_inf(null, missing, 1)) ],
    "f": is_missing(if_inf(missing, null, 1)) ],
    "g": if_inf(float("INF"), 1) ],
    "h": to_string(if_inf(float("INF"), double("NaN"), 1)) ]
};

The expected result is:

{ "a": true, "b": true, "c": true, "d": 1, "e": true, "f": true, "g": 1, "h": "NaN" }

The function has an alias ifinf.

if_nan (ifnan)

Syntax:

if_nan(expression1, expression2, ... expressionN)

Finds first argument which is a non-NaN number
Arguments:
- expressionI : an expression (any type is allowed).
Return Value:
- a missing if missing argument was encountered before the first non-NaN number argument
- a null if null argument or any other non-number argument was encountered before the first non-NaN number argument
- the first non-NaN number argument otherwise

Example:

{
    "a": is_null(if_nan(null)),
    "b": is_missing(if_nan(missing)),
    "c": is_null(if_nan(double("NaN"))),
    "d": if_nan(1, null, missing) ],
    "e": is_null(if_nan(null, missing, 1)) ],
    "f": is_missing(if_nan(missing, null, 1)) ],
    "g": if_nan(float("NaN"), 1) ],
    "h": to_string(if_nan(float("NaN"), double("INF"), 1)) ]
};

The expected result is:

{ "a": true, "b": true, "c": true, "d": 1, "e": true, "f": true, "g": 1, "h": "INF" }

The function has an alias ifnan.

if_nan_or_inf (ifnanorinf)

Syntax:

if_nan_or_inf(expression1, expression2, ... expressionN)

Finds first argument which is a non-infinite (INF or-INF) and non-NaN number
Arguments:
- expressionI : an expression (any type is allowed).
Return Value:
- a missing if missing argument was encountered before the first non-infinite and non-NaN number argument
- a null if null argument or any other non-number argument was encountered before the first non-infinite and non-NaN number argument
- the first non-infinite and non-NaN number argument otherwise

Example:

{
    "a": is_null(if_nan_or_inf(null)),
    "b": is_missing(if_nan_or_inf(missing)),
    "c": is_null(if_nan_or_inf(double("NaN"), double("INF"))),
    "d": if_nan_or_inf(1, null, missing) ],
    "e": is_null(if_nan_or_inf(null, missing, 1)) ],
    "f": is_missing(if_nan_or_inf(missing, null, 1)) ],
    "g": if_nan_or_inf(float("NaN"), float("INF"), 1) ],
};

The expected result is:

{ "a": true, "b": true, "c": true, "d": 1, "e": true, "f": true, "g": 1 }

The function has an alias ifnanorinf.

null_if (nullif)

Syntax:
```
null_if(expression1, expression2)
```
Compares two arguments and returns null if they are equal, otherwise returns the first argument.
Arguments:
- expressionI : an expression (any type is allowed).
Return Value:
- missing if any argument is a missing value,
- null if
  - any argument is a null value but no argument is a missing value, or
  - argument1 = argument2
- a value of the first argument otherwise

Example:

{
    "a": null_if("analytics", "analytics"),
    "b": null_if(1, 2)
};

The expected result is:
```
{ "a": null, "b": 1 }
```

The function has an alias nullif.

missing_if (missingif)

Syntax:
```
missing_if(expression1, expression2)
```
Compares two arguments and returns missing if they are equal, otherwise returns the first argument.
Arguments:
- expressionI : an expression (any type is allowed).
Return Value:
- missing if
  - any argument is a missing value, or
  - no argument is a null value and argument1 = argument2
- null if any argument is a null value but no argument is a missing value
- a value of the first argument otherwise

Example:

{
    "a": missing_if("analytics", "analytics")
    "b": missing_if(1, 2),
};

The expected result is:
```
{ "b": 1 }
```

The function has an alias missingif.

nan_if (nanif)

Syntax:
```
nan_if(expression1, expression2)
```
Compares two arguments and returns NaN value if they are equal, otherwise returns the first argument.
Arguments:
- expressionI : an expression (any type is allowed).
Return Value:
- missing if any argument is a missing value,
- null if any argument is a null value but no argument is a missing value
- NaN value of type double if argument1 = argument2
- a value of the first argument otherwise

Example:

{
    "a": to_string(nan_if("analytics", "analytics")),
    "b": nan_if(1, 2)
};

The expected result is:
```
{ "a": "NaN", "b": 1 }
```

The function has an alias nanif.

posinf_if (posinfif)

Syntax:
```
posinf_if(expression1, expression2)
```
Compares two arguments and returns +INF value if they are equal, otherwise returns the first argument.
Arguments:
- expressionI : an expression (any type is allowed).
Return Value:
- missing if any argument is a missing value,
- null if any argument is a null value but no argument is a missing value
- +INF value of type double if argument1 = argument2
- a value of the first argument otherwise

Example:

{
    "a": to_string(posinf_if("analytics", "analytics")),
    "b": posinf_if(1, 2)
};

The expected result is:
```
{ "a": "+INF", "b": 1 }
```

The function has an alias posinfif.

neginf_if (neginfif)

Syntax:
```
neginf_if(expression1, expression2)
```
Compares two arguments and returns -INF value if they are equal, otherwise returns the first argument.
Arguments:
- expressionI : an expression (any type is allowed).
Return Value:
- missing if any argument is a missing value,
- null if any argument is a null value but no argument is a missing value
- -INF value of type double if argument1 = argument2
- a value of the first argument otherwise

Example:

{
    "a": to_string(neginf_if("analytics", "analytics")),
    "b": neginf_if(1, 2)
};

The expected result is:
```
{ "a": "-INF", "b": 1 }
```

The function has an alias neginfif.

Environment and Identifier Functions

uuid

Syntax:
```
uuid()
```
Generates a uuid.
Arguments:
- none
Return Value:
- a generated, random uuid.

JSON Functions

decode_json

Syntax:
```
decode_json(expr)
```
Unmarshals the JSON-encoded string into a N1QL value.
Arguments:
- expr: a JSON-encoded string.
Return Value:
- A N1QL value.
- If expr is NULL or an empty string then NULL is returned.
- If expr is MISSING then MISSING is returned.
Example:
```
decode_json("{\"abc\":1,\"def\":2}");
```
The expected result is:
```
{
  "abc": 1,
  "def": 2
}
```

encode_json

Syntax:
```
encode_json(expr)
```
Marshals the N1QL value into a JSON-encoded string.
Arguments:
- expr: a N1QL value.
Return Value:
- A JSON-encoded string.
- If expr is NULL then NULL is returned.
- If expr is MISSING then MISSING is returned.
Example:
```
encode_json({"abc":1,"def":2});
```
The expected result is:
```
"{ \"abc\": 1, \"def\": 2 }"
```

encoded_size

Syntax:
```
encoded_size(expr)
```
Returns the number of bytes in an uncompressed JSON encoding of the value. The exact size is implementation-dependent.
Arguments:
- expr: a N1QL value.
Return Value:
- An integer. Never MISSING or NULL. Returns 0 for MISSING.
Example:
```
encoded_size({"abc":1,"def":2});
```
The expected result is:
```
22
```