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Diffstat (limited to 'includes/js/dojox/lang/functional/lambda.js')
-rw-r--r-- | includes/js/dojox/lang/functional/lambda.js | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/includes/js/dojox/lang/functional/lambda.js b/includes/js/dojox/lang/functional/lambda.js new file mode 100644 index 0000000..60be9f3 --- /dev/null +++ b/includes/js/dojox/lang/functional/lambda.js @@ -0,0 +1,110 @@ +if(!dojo._hasResource["dojox.lang.functional.lambda"]){ //_hasResource checks added by build. Do not use _hasResource directly in your code. +dojo._hasResource["dojox.lang.functional.lambda"] = true; +dojo.provide("dojox.lang.functional.lambda"); + +// This module adds high-level functions and related constructs: +// - anonymous functions built from the string + +// Acknoledgements: +// - lambda() is based on work by Oliver Steele +// (http://osteele.com/sources/javascript/functional/functional.js) +// which was published under MIT License + +// Notes: +// - lambda() produces functions, which after the compilation step are +// as fast as regular JS functions (at least theoretically). + +// Lambda input values: +// - returns functions unchanged +// - converts strings to functions +// - converts arrays to a functional composition + +(function(){ + var df = dojox.lang.functional; + + // split() is augmented on IE6 to ensure the uniform behavior + var split = "ab".split(/a*/).length > 1 ? String.prototype.split : + function(sep){ + var r = this.split.call(this, sep), + m = sep.exec(this); + if(m && m.index == 0){ r.unshift(""); } + return r; + }; + + var lambda = function(/*String*/ s){ + var args = [], sects = split.call(s, /\s*->\s*/m); + if(sects.length > 1){ + while(sects.length){ + s = sects.pop(); + args = sects.pop().split(/\s*,\s*|\s+/m); + if(sects.length){ sects.push("(function(" + args + "){return (" + s + ")})"); } + } + }else if(s.match(/\b_\b/)){ + args = ["_"]; + }else{ + var l = s.match(/^\s*(?:[+*\/%&|\^\.=<>]|!=)/m), + r = s.match(/[+\-*\/%&|\^\.=<>!]\s*$/m); + if(l || r){ + if(l){ + args.push("$1"); + s = "$1" + s; + } + if(r){ + args.push("$2"); + s = s + "$2"; + } + }else{ + // the point of the long regex below is to exclude all well-known + // lower-case words from the list of potential arguments + var vars = s. + replace(/(?:\b[A-Z]|\.[a-zA-Z_$])[a-zA-Z_$\d]*|[a-zA-Z_$][a-zA-Z_$\d]*:|this|true|false|null|undefined|typeof|instanceof|in|delete|new|void|arguments|decodeURI|decodeURIComponent|encodeURI|encodeURIComponent|escape|eval|isFinite|isNaN|parseFloat|parseInt|unescape|dojo|dijit|dojox|window|document|'(?:[^'\\]|\\.)*'|"(?:[^"\\]|\\.)*"/g, ""). + match(/([a-z_$][a-z_$\d]*)/gi) || []; + var t = {}; + dojo.forEach(vars, function(v){ + if(!(v in t)){ + args.push(v); + t[v] = 1; + } + }); + } + } + return {args: args, body: "return (" + s + ");"}; // Object + }; + + var compose = function(/*Array*/ a){ + return a.length ? + function(){ + var i = a.length - 1, x = df.lambda(a[i]).apply(this, arguments); + for(--i; i >= 0; --i){ x = df.lambda(a[i]).call(this, x); } + return x; + } + : + // identity + function(x){ return x; }; + }; + + dojo.mixin(df, { + // lambda + buildLambda: function(/*String*/ s){ + // summary: builds a function from a snippet, returns a string, + // which represents the function. + // description: This method returns a textual representation of a function + // built from the snippet. It is meant to be evaled in the proper context, + // so local variables can be pulled from the environment. + s = lambda(s); + return "function(" + s.args.join(",") + "){" + s.body + "}"; // String + }, + lambda: function(/*Function|String|Array*/ s){ + // summary: builds a function from a snippet, or array (composing), returns + // a function object; functions are passed through unmodified. + // description: This method is used to normalize a functional representation + // (a text snippet, an array, or a function) to a function object. + if(typeof s == "function"){ return s; } + if(s instanceof Array){ return compose(s); } + s = lambda(s); + return new Function(s.args, s.body); // Function + } + }); +})(); + +} |