plainleaf/docs/API/string.md

tags, references

tags	references
api/lua	client/space_lua/stdlib/string.ts client/space_lua/stdlib/string_pack.ts

The string module contains Lua string operations and Space Lua extensions.

Note

Note Since string values use string as their metatable, these APIs can also be called as methods. For example, someString:startsWith("h") is equivalent to string.startsWith(someString, "h").

Lua pattern matching

Lua patterns are not regular expressions. Space Lua translates Lua patterns to JavaScript regular expressions and has a few compatibility differences:

1. Magic characters ^$()%.[]*+-? must be escaped to represent literal characters. Standard Lua does not require escaping a magic character when it is not contextually magic, so patterns such as %d-- can behave differently in Space Lua.
2. Space Lua allows repetition characters (?, *, +, and -) to apply to captures; standard Lua does not.
3. The nth captured string (%n), balanced match (%bxy), and frontier pattern (%f[set]) forms from the Lua 5.4 pattern manual may not be supported.

The string.matchRegex and string.matchRegexAll extensions use JavaScript regular expressions instead of Lua patterns.

Examples of patterns that differ:

print(string.match("1234", "(%d)+"))
-- Space Lua prints "4" because repetition applies to the capture.
-- Standard Lua returns nil.

print(string.match("*", "*"))
-- Space Lua reports an invalid regular expression.
-- Standard Lua prints "*".

print(string.match("2024-03-14", "%d+-(%d+)-%d+"))
-- Space Lua reports an invalid regular expression because the hyphens are not escaped.
-- Standard Lua prints "03".

${spacelua.renderApiDocumentation("string")}