Built-in Functions (Not a Library)

L4 includes several built-in functions that are always available without importing any library. These are implemented in the compiler core:

Type Coercion Builtins

Function	Signature	Description
TOSTRING	NUMBER/BOOLEAN/DATE → STRING	Convert to string representation
TONUMBER	STRING → MAYBE NUMBER	Parse string to number
TODATE	STRING → MAYBE DATE	Parse string to date
TRUNC	NUMBER, NUMBER → NUMBER	Truncate decimal places
AS STRING	value AS STRING	Inline string conversion

Numeric Builtins

Function	Description
FLOOR	Round down to integer
CEILING	Round up to integer
ROUND	Round to nearest integer
EXPONENT	Exponentiation (base, power)
LN	Natural logarithm
LOG10	Base-10 logarithm
SQRT	Square root
SIN, COS, TAN	Trigonometric functions (radians)
ASIN, ACOS, ATAN	Inverse trigonometric functions

String Builtins

Function	Description
STRINGLENGTH	Length of string
SUBSTRING	Extract substring
TOUPPER	Convert to uppercase
TOLOWER	Convert to lowercase

Date Builtins

Function	Description
DATE_FROM_DMY	Construct DATE from day, month, year
DATE_FROM_SERIAL	Construct DATE from serial number
DATE_SERIAL	Get serial number from DATE
DATE_DAY	Extract day from DATE
DATE_MONTH	Extract month from DATE
DATE_YEAR	Extract year from DATE
TODAY	Current date

HTTP and JSON Builtins

Function	Signature	Description
FETCH	STRING → STRING	HTTP GET request
POST	STRING, STRING, STRING → STRING	HTTP POST request
ENV	STRING → STRING	Read environment variable
JSONENCODE	a → STRING	Convert value to JSON string
JSONDECODE	STRING → EITHER STRING a	Parse JSON string to value

For detailed HTTP/JSON documentation, see HTTP and JSON.

For detailed coercion documentation, see Coercions.