Summary

Matches a pattern against a string

Prototype

lpeg.match (pattern, subject [, init])

Description

The matching function. It attempts to match the given pattern against the subject string. If the match succeeds, returns the index in the subject of the first character after the match, or the values of captured values (if the pattern captured any value).

An optional numeric argument init makes the match starts at that position in the subject string. As usual in Lua libraries, a negative value counts from the end.

Unlike typical pattern-matching functions, match works only in anchored mode; that is, it tries to match the pattern with a prefix of the given subject string (at position init), not with an arbitrary substring of the subject. So, if we want to find a pattern anywhere in a string, we must either write a loop in Lua or write a pattern that matches anywhere. This second approach is easy and quite efficient.

See Also ...

Lua functions

lpeg.B - Matches patt n characters behind the current position, consuming no input
lpeg.C - Creates a simple capture
lpeg.Carg - Creates an argument capture
lpeg.Cb - Creates a back capture
lpeg.Cc - Creates a constant capture
lpeg.Cf - Creates a fold capture
lpeg.Cg - Creates a group capture
lpeg.Cmt - Creates a match-time capture
lpeg.Cp - Creates a position capture
lpeg.Cs - Creates a substitution capture
lpeg.Ct - Creates a table capture
lpeg.locale - Returns a table of patterns matching the current locale
lpeg.P - Converts a value into a pattern
lpeg.print - Outputs debugging information to stdout
lpeg.R - Returns a pattern that matches a range of characters
lpeg.S - Returns a pattern that matches a set of characters
lpeg.setmaxstack - Sets the maximum size for the backtrack stack
lpeg.type - Tests if a value is a pattern
lpeg.V - Creates a non-terminal variable for a grammar
lpeg.version - Returns the LPeg version

Topics

Lua bc (big number) functions
Lua bit manipulation functions
Lua LPEG library
Lua package functions
Lua PCRE regular expression functions
Lua script extensions
Lua string functions
Lua syntax
Lua table functions
Lua utilities
Regular Expressions
Scripting
Scripting callbacks - plugins

(Help topic: lua=lpeg.match)