This module directly imports all functions from the mw.ustring library. Documentation for each function can be found there.
The module takes an indefinite number of arguments. All arguments are coerced as number type if possible. If you wish for something to remain a string, you can simply escape it by insert \ at the beginning of the string.
You can also wrap results in tags. All non-number indexed arguments will be passed to
frame:extensionTag
Note: Only the first match is returned. Additional returns are omitted because mw.ustring.gsub's second return value is generally undesirable.
Example using tag arguments
{{#invoke:Ustring|match
|{{Module:Ustring}}|%s%s%sif%snot%s[^%s]+%sthen.+%
<!--enter an actual newline character to match '\n'-->%s%s%send
|tag=syntaxhighlight|lang=lua}}
produces:
ifnotfargs.tagthenreturn(what(unpack(args)))-- Outside parens truncate to first result avoiding tail callendlocaltagargs={}forx,yinpairs(fargs)doifnotfargsused[x]thentagargs[x]=yendend
Note that:
<syntaxhighlight lang="lua">{{#invoke:Ustring|match
|{{Module:Ustring}}|%s%s%sif%snot%s[^%s]+%sthen.+%
<!--enter an actual newline character to match '\n'-->%s%s%send}}</syntaxhighlight>
produces:
{{#invoke:Ustring|match|{{Module:Ustring}}|%s%s%sif%snot%s[^%s]+%sthen.+%<!--enter an actual newline character to match '\n'-->%s%s%send}}
Errors
Errors from accessing mw.ustring should be maintained, e.g.:
{{#invoke:Ustring|xyzzy}}
should produce:
Script error: The function "xyzzy" does not exist.
and
{{#invoke:Ustring|maxPatternLength}}
should produce:
Script error: "maxPatternLength" is not a function.