56 lines
2.0 KiB
JavaScript
56 lines
2.0 KiB
JavaScript
|
//>>built
|
||
|
|
// wrapped by build app
|
||
|
|
define("dojox/lang/functional/listcomp", ["dijit","dojo","dojox"], function(dijit,dojo,dojox){
|
||
|
|
dojo.provide("dojox.lang.functional.listcomp");
|
||
|
|
|
||
|
|
// This module adds high-level functions and related constructs:
|
||
|
|
// - list comprehensions similar to JavaScript 1.7
|
||
|
|
|
||
|
|
// Notes:
|
||
|
|
// - listcomp() produces functions, which after the compilation step are
|
||
|
|
// as fast as regular JS functions (at least theoretically).
|
||
|
|
|
||
|
|
(function(){
|
||
|
|
var g_re = /\bfor\b|\bif\b/gm;
|
||
|
|
|
||
|
|
var listcomp = function(/*String*/ s){
|
||
|
|
var frag = s.split(g_re), act = s.match(g_re),
|
||
|
|
head = ["var r = [];"], tail = [], i = 0, l = act.length;
|
||
|
|
while(i < l){
|
||
|
|
var a = act[i], f = frag[++i];
|
||
|
|
if(a == "for" && !/^\s*\(\s*(;|var)/.test(f)){
|
||
|
|
f = f.replace(/^\s*\(/, "(var ");
|
||
|
|
}
|
||
|
|
head.push(a, f, "{");
|
||
|
|
tail.push("}");
|
||
|
|
}
|
||
|
|
return head.join("") + "r.push(" + frag[0] + ");" + tail.join("") + "return r;"; // String
|
||
|
|
};
|
||
|
|
|
||
|
|
dojo.mixin(dojox.lang.functional, {
|
||
|
|
buildListcomp: function(/*String*/ s){
|
||
|
|
// summary: builds a function from a text snippet, which represents a valid
|
||
|
|
// JS 1.7 list comprehension, returns a string, which represents the function.
|
||
|
|
// description: This method returns a textual representation of a function
|
||
|
|
// built from the list comprehension text snippet (conformant to JS 1.7).
|
||
|
|
// It is meant to be evaled in the proper context, so local variable can be
|
||
|
|
// pulled from the environment.
|
||
|
|
return "function(){" + listcomp(s) + "}"; // String
|
||
|
|
},
|
||
|
|
compileListcomp: function(/*String*/ s){
|
||
|
|
// summary: builds a function from a text snippet, which represents a valid
|
||
|
|
// JS 1.7 list comprehension, returns a function object.
|
||
|
|
// description: This method returns a function built from the list
|
||
|
|
// comprehension text snippet (conformant to JS 1.7). It is meant to be
|
||
|
|
// reused several times.
|
||
|
|
return new Function([], listcomp(s)); // Function
|
||
|
|
},
|
||
|
|
listcomp: function(/*String*/ s){
|
||
|
|
// summary: executes the list comprehension building an array.
|
||
|
|
return (new Function([], listcomp(s)))(); // Array
|
||
|
|
}
|
||
|
|
});
|
||
|
|
})();
|
||
|
|
|
||
|
|
});
|