Built-in functions

Built-in functions are part of the language, so they work in every file without an IMPORT. Functions that come from a library, such as map, sum or Date, are listed under Standard libraries.

Operators (+, AND, EQUALS, UNLESS, FOLLOWED BY and the rest) are described under Operators. The conversions TOSTRING, TONUMBER, TODATE, TOTIME, TODATETIME and AS STRING are described under Coercions.

Numbers

Function	Inputs	Gives	What it does
ISINTEGER	NUMBER	BOOLEAN	TRUE if the number has no fractional part
FLOOR	NUMBER	NUMBER	Rounds down to a whole number
CEILING	NUMBER	NUMBER	Rounds up to a whole number
ROUND	NUMBER	NUMBER	Rounds to the nearest whole number; a half goes to the even number, so 2.5 gives 2 and 3.5 gives 4
TRUNC	NUMBER, NUMBER	NUMBER	TRUNC x n cuts x toward zero to n decimal places: TRUNC 12.987 2 is 12.98. A negative n cuts to tens, hundreds and so on: TRUNC 123.45 (-1) is 120
EXPONENT	NUMBER, NUMBER	NUMBER	EXPONENT base power: EXPONENT 2 10 is 1024
SQRT	NUMBER	NUMBER	Square root
LN	NUMBER	NUMBER	Natural logarithm; an error for 0 or less
LOG10	NUMBER	NUMBER	Base-10 logarithm; an error for 0 or less
SIN, COS, TAN	NUMBER	NUMBER	Trigonometry, in radians
ASIN, ACOS	NUMBER	NUMBER	Inverse sine and cosine; an error outside -1 to 1
ATAN	NUMBER	NUMBER	Inverse tangent

The math library has lowercase versions (ln, sqrt, asin, ...) that give NOTHING instead of an error.

Text

Positions in a STRING count from 0.

Function	Inputs	Gives	What it does
CONCAT	STRING, STRING, ...	STRING	Joins any number of strings: CONCAT "Hello, ", name, "!"
STRINGLENGTH	STRING	NUMBER	The number of characters
TOUPPER	STRING	STRING	Upper case
TOLOWER	STRING	STRING	Lower case
TRIM	STRING	STRING	Without spaces at the start and end
CONTAINS	STRING, STRING	BOOLEAN	CONTAINS text part: TRUE if part occurs in text
STARTSWITH	STRING, STRING	BOOLEAN	STARTSWITH text start
ENDSWITH	STRING, STRING	BOOLEAN	ENDSWITH text end
INDEXOF	STRING, STRING	NUMBER	INDEXOF text part: the position of the first part, or -1
SPLIT	STRING, STRING	LIST OF STRING	SPLIT text separator: SPLIT "a,b" "," is LIST "a", "b"
CHARAT	STRING, NUMBER	STRING	CHARAT text position: one character
SUBSTRING	STRING, NUMBER, NUMBER	STRING	SUBSTRING text start length: SUBSTRING "hello" 1 3 is "ell"
REPLACE	STRING, STRING, STRING	STRING	REPLACE text old new: every old replaced by new

STARTSWITH and ENDSWITH are written as one word.

Dates

Function	Inputs	Gives	What it does
DATE_FROM_DMY	NUMBER, NUMBER, NUMBER	DATE	The date from day, month and year
DATE_FROM_SERIAL	NUMBER	DATE	The date with this serial number
DATE_SERIAL	DATE	NUMBER	The date's serial number (a count of days)
DATE_DAY	DATE	NUMBER	The day of the month
DATE_MONTH	DATE	NUMBER	The month
DATE_YEAR	DATE	NUMBER	The year
DATEVALUE	STRING	EITHER STRING DATE	Reads date text such as "2024-02-01"; LEFT holds the error
TODAY	none	DATE	Today's date in the document's time zone; needs TIMEZONE IS

The daydate library builds on these with Date, weekdays, months and more.

Times of day

Function	Inputs	Gives	What it does
TIME_FROM_HMS	NUMBER, NUMBER, NUMBER	TIME	The time from hour, minute and second
TIME_FROM_SERIAL	NUMBER	TIME	The time from a fraction of a day (0.5 is noon)
TIME_SERIAL	TIME	NUMBER	The time as a fraction of a day
TIME_HOUR	TIME	NUMBER	0 to 23
TIME_MINUTE	TIME	NUMBER	0 to 59
TIME_SECOND	TIME	NUMBER	0 to 59
TIMEVALUE	STRING	EITHER STRING NUMBER	Reads time text such as "12:00" as a fraction of a day; LEFT holds the error
CURRENTTIME	none	TIME	The current time in the document's time zone; needs TIMEZONE IS

Date and time together

Function	Inputs	Gives	What it does
DATETIME_FROM_DTZ	DATE, TIME, STRING	DATETIME	A DATETIME from a date, a time and an IANA time zone name
DATETIME_DATE	DATETIME	DATE	The local date
DATETIME_TIME	DATETIME	TIME	The local time of day
DATETIME_TZ	DATETIME	STRING	The IANA time zone name
DATETIME_SERIAL	DATETIME	NUMBER	A serial number counted in UTC
NOW	none	DATETIME	The current moment; in UTC when the file has no TIMEZONE IS
TIMEZONE	none	STRING	The document's time zone name; needs TIMEZONE IS

TIMEZONE IS is a line of its own at the top level of a file that sets the document's time zone, such as TIMEZONE IS "Asia/Singapore". The timezone library has constants for common zones, and datetime builds on these functions.

Regulative traces

Function	Inputs	Gives	What it does
WAITUNTIL	NUMBER	EVENT a b	An event that matches no party and no action; in a #TRACE it moves time forward to the given time
EVALTRACE	DEONTIC a b, NUMBER, LIST OF EVENT a b	DEONTIC a b	The function behind #TRACE: what remains of a rule after the events, starting at the given time

See EVENT and Regulative rules.

HTTP and JSON

Function	Inputs	Gives	What it does
FETCH	STRING	STRING	Sends an HTTPS GET request and gives the response body
POST	STRING, STRING, STRING	STRING	Sends an HTTPS POST request: URL, headers, body
ENV	STRING	MAYBE STRING	The value of an environment variable, or NOTHING
JSONENCODE	a	STRING	Any value as JSON text
JSONDECODE	STRING	EITHER STRING a	JSON text as a value of the expected type; LEFT holds the error

Details, including the header format and how records are encoded, are under HTTP and JSON.