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Diffstat (limited to 'includes/js/dojox/lang/functional/listcomp.js')
-rw-r--r-- | includes/js/dojox/lang/functional/listcomp.js | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/includes/js/dojox/lang/functional/listcomp.js b/includes/js/dojox/lang/functional/listcomp.js new file mode 100644 index 0000000..adb4883 --- /dev/null +++ b/includes/js/dojox/lang/functional/listcomp.js @@ -0,0 +1,54 @@ +if(!dojo._hasResource["dojox.lang.functional.listcomp"]){ //_hasResource checks added by build. Do not use _hasResource directly in your code. +dojo._hasResource["dojox.lang.functional.listcomp"] = true; +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 = []; + for(var i = 0; i < act.length;){ + 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 + } + }); +})(); + +} |