Skip to content

lualib/string-functions

string utility module. Re-exports the native string.* functions (with handy aliases) and adds nil-safe helpers (the defaultValue guard, isEmptyString/isNil tests…) used heavily across RitnLib.
Source lualib/string-functions.lua
Type function module (returned table)
Access local string = require(ritnlib.defines.string)

The returned table doesn't replace native string globally: you capture it in a local variable.

Constant

TOKEN_EMPTY_STRING :: "" [Read]

Empty-string marker, reused by the guards.

RitnLib helpers

defaultValue(value, default?) → string

Standard nil-safe guard: returns value if it's a string, otherwise default (itself defaulting to "").

Parameters: value :: any · default :: string? (default "").

isString(value) → boolean

true if value is a string.

isEmptyString(value) → boolean · isNotEmptyString(value) → boolean

isEmptyString: true if value is the empty string, nil, or not a string. isNotEmptyString is its negation.

isNil(value) → boolean · isNotNil(value) → boolean

== nil test and its negation.

equals(value1, value2) → boolean

Plain == comparison.

startsWith(str, value) → boolean

true if str starts with value (via string.find position 1).

Warning — value is interpreted as a Lua pattern, not a plain string: magic characters (-, %, .…) are active.

Native string.* re-exports

Available as-is (see the Lua/Factorio docs), plus a few aliases:

Function Alias
byte, char, dump, find, format, gmatch, match, rep, reverse, sub —
gsub replace
len length
lower toLower
upper toUpper

Usage example

local string = require(ritnlib.defines.string)

local name = string.defaultValue(maybe_name, "anonymous")  -- nil-safe
if string.isNotEmptyString(input) then
    -- …
end
local upper = string.toUpper("ritn")

See also