Re: Lua string library partially reimplemented in Lua

["Mark Meijer" <meijer78@...>]

Sounds great!

2008/9/17 David Manura <dm.lua@math2.org>:
> Here is the Lua string library (lstrlib.c) partially reimplemented in
> Lua (mainly, string.find and string.match functions):
>
>  http://lua-users.org/wiki/StringLibraryInLua
>
> Reimplementing these in Lua provides a number of generalizations and
> possible applications:
>
>  * The pattern matching library can be extended in Lua
>
>  * The pattern matching can match not just strings but more generally
> arrays of chars and arrays of arbitrary values, including arrays
> backed by metamethods.  The filearray.lua example included in the
> appendix allows a large file to be accessed via an array interface,
> which can then be matched by these string.find/string.match functions,
> without ever loading the entire file into memory at once:
>
>  local S = require "stringinlua"  -- reimplemented pattern matching functions
>  local FA = require "filearray"   -- table array interface to files
>  local SA = require "stringarray" -- table array interface to simple strings
>
>  -- match text in file manual.html (internally, only a 1K is loaded at a time)
>  assert(S.match(assert(FA 'manual.html'), SA'block ::= (%w+)') == 'chunk')
>
> Another example, of using this to match arrays that are not char
> strings is this:
>
>  local TA = require "tablearray" -- table array interface to tables
>
>  -- match value false followed by one or more occurrences of value 'test'
>  assert(S.match(TA{2,false,"test","test",2}, TA{false,"test", '+'})
>            == TA{false,"test", "test"})
>
> Unicode matching may be another application (i.e. arrays of Unicode characters).
>