Built in Functions

Built-in Function Reference

Function names are case-sensitive. Wrong argument counts, invalid conversions, invalid paths, and out-of-range indexes throw RuntimeException.

Built-ins participate in the same overload resolution model as user and host functions. New integrations should read built-in metadata through RuleScriptAnalysisResult.Functions and RuleScriptFunctionSymbol where Kind == RuleScriptFunctionKind.Builtin.

General and Type Helpers

Function	Return	Description
Print(value)	any	Returns value and reports a host-observable Print runtime event.
ToString(value)	string	Converts a value to invariant text; null becomes an empty string.
TypeOf(value)	string	Returns null, string, bool, number, array, or object.
IsNull(value)	bool	Returns whether the value is null.
Coalesce(value, fallback)	any	Returns value unless it is null; otherwise returns fallback.

Conversion

Function	Return	Description
ParseInt(value)	number	Parses a string or whole numeric value as an integer number.
ParseDecimal(value)	number	Parses a string or numeric value as a decimal number.
ParseBool(value)	bool	Parses a bool or string value as a boolean.

Strings

Function	Return	Description
Trim(value)	string	Converts to text and trims whitespace.
ToUpper(value)	string	Converts to uppercase invariant text.
ToLower(value)	string	Converts to lowercase invariant text.
StartsWith(value, prefix)	bool	Tests with ordinal comparison.
EndsWith(value, suffix)	bool	Tests with ordinal comparison.
Contains(value, searchValue)	bool	Tests with ordinal comparison.
Split(value, separator)	array	Splits text into an array.
Join(separator, values)	string	Joins array values into text.
Replace(value, oldValue, newValue)	string	Replaces ordinal text matches.
Substring(value, start, length)	string	Extracts a zero-based range.
Length(value)	number	Returns array count or text length.

Arrays

Array helpers mutate the supplied array when applicable.

Function	Return	Description
ArrayAdd(array, value)	array	Appends a value and returns the same array.
ArrayInsert(array, index, value)	array	Inserts a value at a zero-based index.
ArrayRemove(array, value)	bool	Removes the first matching value and returns whether one was removed.
ArrayRemoveAt(array, index)	any	Removes and returns the indexed value.
ArraySort(array)	array	Sorts an all-string or all-number array ascending.
ArrayContains(array, value)	bool	Tests whether the array contains a matching value.
ArrayClear(array)	array	Removes all items and returns the same array.

var values = [3, 1, 2];
ArrayAdd(values, 4);
ArraySort(values);
var hasTwo = ArrayContains(values, 2);

Objects

Function	Return	Description
ObjectKeys(object)	array	Returns property names in ordinal sort order.
ObjectContainsKey(object, key)	bool	Tests whether a string key exists.

var robot = { status: "OK", distance: 519 };
var keys = ObjectKeys(robot);
var hasStatus = ObjectContainsKey(robot, "status");

Mathematics

Function	Return	Description
Abs(value)	number	Returns the absolute value.
Min(left, right)	number	Returns the smaller number.
Max(left, right)	number	Returns the larger number.
Clamp(value, min, max)	number	Restricts a number to an inclusive range.
Round(value)	number	Rounds to the nearest whole number.
Floor(value)	number	Rounds down.
Ceiling(value)	number	Rounds up.

JSON

Function	Return	Description
JsonParse(json)	object	Parses JSON text into RuleScript objects, arrays, and primitive values.
JsonStringify(value)	string	Serializes a supported value to JSON text.
JsonGet(value, path)	any	Reads a dot-separated path, including array indexes such as items.0.name.
JsonSet(value, path, newValue)	any	Sets an existing path and returns the updated root.
JsonExists(value, path)	bool	Tests whether a path exists.

var payload = JsonParse("{ \"items\": [{ \"name\": \"A\" }] }");
var name = JsonGet(payload, "items.0.name");
JsonSet(payload, "items.0.name", "B");
var json = JsonStringify(payload);

JsonSet mutates dictionaries and lists in place.