lua_maparray provides a simple class and a tiny collection of basic functions for straightforward and compact mapping 1D arrays

The class Map allows one to construct lambda functions without complicated native Lua syntax. These functions may be used in-place to map arrays. Though it's an intended purpose of the class, these functions can be used anywhere one needs lambdas.

For to shortcut a constructing new instances of Map class, there's a wrapper function wrap().

There are two general purpose functions map() and mapa() to iterate the given array and apply the given function to each element. map() traverses only indexed part of the table, while mapa() uses pairs() for iterating. Mapping occures in-place, with a side-effect on the given table. Functions return the table.

The only difference of these functions from well-known [from other languages] analog is that these ones receives array (table) as their 1st parameter and map-function as the 2nd parameter. It's a natural order for object-oriented fashion, hence it's implemented here.

No reason why one should use map() and mapa() from this module. They are included because Lua does not provide built-in anything like these.

No module description can be complete without any example code. Here it goes:

local map = require "maparray"; local = map.wrap; local sequence = {0, 1, 2, 3, 4}; -- return negations of squares map.map(sequence, - () _()); -- native syntax for lambda function would be like this: -- map.map(sequence, function(a) return - a a end); -- print altered sequence print(unpack(sequence));

See test.lua for more examples.