Built-in Functions

Conversions, math, strings, collections and utilities.

Built-ins are part of the language and need no include. There are 69, including the Custom RPC helpers (HandleRPC, CheckRPC, RPCPack).

Conversion & inspection

knight

len("hello")      // 5
str(42)           // "42"
int("7")          // 7
float("2.5")      // 2.5
bool(0)           // false
typeof(1.5)       // "float"
is_null(null)     // true
is_array([1,2])   // true

Math

knight

abs(-5)           // 5
min(3, 8)         // 3
max(3, 8)         // 8
clamp(20, 0, 10)  // 10
round(2.6)        // 3
floor(2.9)        // 2
ceil(2.1)         // 3
sqrt(9.0)         // 3
pow(2.0, 3.0)     // 8
random(1, 6)      // 1..6

Strings

knight

upper("ab")               // "AB"
lower("AB")               // "ab"
trim("  x  ")             // "x"
substr("hello", 1, 3)     // "ell"
contains("abc", "b")      // true
starts_with("abc", "a")   // true
ends_with("abc", "c")     // true
replace("a-b", "-", "+")  // "a+b"
split("a,b,c", ",")       // ["a","b","c"]
join(["a","b"], "-")      // "a-b"

Collections

knight

let a = array();
a = push(a, 10);
a = push(a, 20);

len(a)        // 2
pop(a)        // 20
at(a, 0)      // 10

let m = map("k", 1);
m["z"] = 9;
keys(m)       // ["k","z"]
has(m, "k")   // true
del(m, "k");

Utilities

knight

format("%s has %d", "CJ", 42)  // "CJ has 42"
distance(0.0, 0.0, 0.0, 3.0, 4.0, 0.0)  // 5

Complete built-in index

Every built-in function with its signature. Built-ins are resolved before natives, so these names cannot be used for gameplay functions.

Conversions and types 13

Signature	Description
`len(any value) -> int`	Length of a string, array or map.
`str(any value) -> string`	Convert a value to a string.
`tostring(any value) -> string`	Alias of str.
`int(any value) -> int`	Convert to an integer (truncates floats, parses strings).
`float(any value) -> float`	Convert to a float.
`bool(any value) -> bool`	Convert to a boolean (truthiness).
`typeof(any value) -> string`	Type name: int, float, string, bool, array, map, Player, ...
`is_null(any value) -> bool`	True when the value is null.
`is_number(any value) -> bool`	True for int or float.
`is_string(any value) -> bool`	True for string.
`is_bool(any value) -> bool`	True for bool.
`is_array(any value) -> bool`	True for array.
`is_map(any value) -> bool`	True for map.

Numbers 11

Signature	Description
`abs(number) -> float`	Absolute value.
`round(number) -> int`	Round to the nearest integer.
`floor(number) -> int`	Round down.
`ceil(number) -> int`	Round up.
`sqrt(number) -> float`	Square root.
`pow(base, exponent) -> float`	Raise base to exponent.
`min(a, b) -> float`	Smaller of two numbers.
`max(a, b) -> float`	Larger of two numbers.
`clamp(value, low, high) -> float`	Limit value to the [low, high] range.
`random(max \| min, max) -> int`	random() random int; random(n) 0..n-1; random(a,b) inclusive range.
`sign(number) -> int`	-1, 0 or 1.

Strings 17

Signature	Description
`upper(text) -> string`	Uppercase.
`lower(text) -> string`	Lowercase.
`trim(text) -> string`	Remove leading/trailing whitespace.
`substr(text, start, length) -> string`	Substring by rune index.
`contains(text, part) -> bool`	Text contains part.
`starts_with(text, prefix) -> bool`	Text starts with prefix.
`ends_with(text, suffix) -> bool`	Text ends with suffix.
`replace(text, old, new) -> string`	Replace every occurrence.
`split(text, separator) -> array`	Split into an array of strings.
`join(array, separator) -> string`	Join values into one string.
`repeat(text, count) -> string`	Repeat text count times.
`char(code) -> string`	Character for a code point.
`char_code(text) -> int`	Code point of the first character.
`starts_with_any(text, prefixes) -> bool`	Text starts with any prefix in the array.
`count(text, part) -> int`	Number of non-overlapping occurrences.
`pad_left(text, width, fill) -> string`	Pad on the left to width.
`pad_right(text, width, fill) -> string`	Pad on the right to width.

Arrays and maps 17

Signature	Description
`array(...values) -> array`	Create an array.
`map(key, value, ...) -> map`	Create a map from alternating keys and values.
`push(array, value) -> array`	Append in place and return the array.
`pop(array) -> any`	Remove and return the last element.
`shift(array) -> any`	Remove and return the first element.
`at(array\|map, index\|key) -> any`	Element by index or key; null when absent.
`keys(map) -> array`	Sorted key list.
`values(map) -> array`	Value list.
`has(map, key) -> bool`	Key exists.
`del(map, key) -> bool`	Delete a key in place; true when it existed.
`insert(array, value, index) -> array`	New array with value inserted at index.
`slice(array\|string, start, end) -> any`	Copy of the [start, end) range.
`index_of(array\|map, value) -> int`	Index/key position or -1.
`reverse(array) -> array`	New reversed array.
`sort(array) -> array`	New sorted array (numbers numerically, others as text).
`concat(array, array) -> array`	New array with both arrays appended.
`unique(array) -> array`	New array without duplicates.

Custom RPC 9

Signature	Description
`HandleCustomRPC(int rpcID, Function handler, map options) -> bool`	Register one handler for an RPC id (incoming/outgoing).
`HandleRPC(int rpcID, Function handler, map options) -> bool`	Register a prioritized handler with an optional payload filter.
`CheckRPC(int rpcID, string payload, map options) -> bool`	Predicate: does this id and payload match the criteria?
`UnregisterRPC(int rpcID) -> bool`	Remove every HandleRPC entry for an id.
`RPCHookCount(int rpcID) -> int`	Number of HandleRPC entries for an id.
`SendCustomRPC(int playerID, int rpcID, string payload) -> bool`	Send a custom RPC; playerID -1 broadcasts.
`RPCPack(string tag, any value, ...) -> string`	Build a little-endian payload (u8/u16/u32/i32/f32/s).
`CustomRPCIds() -> array`	Registered custom RPC ids.
`LastCustomRPCStatus() -> string`	ok/ignored/too_large/rate_limited/no_client_mod.

Helpers 2

Signature	Description
`format(pattern, ...values) -> string`	Substitute %s/%d/%f/%v placeholders.
`distance(x1, y1, z1, x2, y2, z2) -> float`	3D distance between two points.