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Diffstat (limited to 'js/dojo-1.7.2/dojox/lang/functional/binrec.js')
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diff --git a/js/dojo-1.7.2/dojox/lang/functional/binrec.js b/js/dojo-1.7.2/dojox/lang/functional/binrec.js new file mode 100644 index 0000000..f32ec8e --- /dev/null +++ b/js/dojo-1.7.2/dojox/lang/functional/binrec.js @@ -0,0 +1,177 @@ +//>>built +// wrapped by build app +define("dojox/lang/functional/binrec", ["dijit","dojo","dojox","dojo/require!dojox/lang/functional/lambda,dojox/lang/functional/util"], function(dijit,dojo,dojox){ +dojo.provide("dojox.lang.functional.binrec"); + +dojo.require("dojox.lang.functional.lambda"); +dojo.require("dojox.lang.functional.util"); + +// This module provides recursion combinators: +// - a binary recursion combinator. + +// Acknoledgements: +// - recursion combinators are inspired by Manfred von Thun's article +// "Recursion Theory and Joy" +// (http://www.latrobe.edu.au/philosophy/phimvt/joy/j05cmp.html) + +// Notes: +// - recursion combinators produce a function, which implements +// their respective recusion patterns. String lambdas are inlined, if possible. + +(function(){ + var df = dojox.lang.functional, inline = df.inlineLambda, + _x ="_x", _z_r_r_z_a = ["_z.r", "_r", "_z.a"]; + + df.binrec = function( + /*Function|String|Array*/ cond, + /*Function|String|Array*/ then, + /*Function|String|Array*/ before, + /*Function|String|Array*/ after){ + // summary: + // Generates a function for the binary recursion pattern. + // All parameter functions are called in the context of "this" object. + // cond: + // The lambda expression, which is used to detect the termination of recursion. + // It accepts the same parameter as the generated recursive function itself. + // This function should return "true", if the recursion should be stopped, + // and the "then" part should be executed. Otherwise the recursion will proceed. + // then: + // The lambda expression, which is called upon termination of the recursion. + // It accepts the same parameters as the generated recursive function itself. + // The returned value will be returned as the value of the generated function. + // before: + // The lambda expression, which is called before the recursive step. + // It accepts the same parameter as the generated recursive function itself. + // The returned value should be an array of two variable, which are used to call + // the generated function recursively twice in row starting from the first item. + // above: + // The lambda expression, which is called after the recursive step. + // It accepts three parameters: two returned values from recursive steps, and + // the original array of parameters used with all other functions. + // The returned value will be returned as the value of the generated function. + + var c, t, b, a, cs, ts, bs, as, dict1 = {}, dict2 = {}, + add2dict = function(x){ dict1[x] = 1; }; + if(typeof cond == "string"){ + cs = inline(cond, _x, add2dict); + }else{ + c = df.lambda(cond); + cs = "_c.apply(this, _x)"; + dict2["_c=_t.c"] = 1; + } + if(typeof then == "string"){ + ts = inline(then, _x, add2dict); + }else{ + t = df.lambda(then); + ts = "_t.apply(this, _x)"; + } + if(typeof before == "string"){ + bs = inline(before, _x, add2dict); + }else{ + b = df.lambda(before); + bs = "_b.apply(this, _x)"; + dict2["_b=_t.b"] = 1; + } + if(typeof after == "string"){ + as = inline(after, _z_r_r_z_a, add2dict); + }else{ + a = df.lambda(after); + as = "_a.call(this, _z.r, _r, _z.a)"; + dict2["_a=_t.a"] = 1; + } + var locals1 = df.keys(dict1), locals2 = df.keys(dict2), + f = new Function([], "var _x=arguments,_y,_z,_r".concat( // Function + locals1.length ? "," + locals1.join(",") : "", + locals2.length ? ",_t=_x.callee," + locals2.join(",") : "", + t ? (locals2.length ? ",_t=_t.t" : "_t=_x.callee.t") : "", + ";while(!", + cs, + "){_r=", + bs, + ";_y={p:_y,a:_r[1]};_z={p:_z,a:_x};_x=_r[0]}for(;;){do{_r=", + ts, + ";if(!_z)return _r;while(\"r\" in _z){_r=", + as, + ";if(!(_z=_z.p))return _r}_z.r=_r;_x=_y.a;_y=_y.p}while(", + cs, + ");do{_r=", + bs, + ";_y={p:_y,a:_r[1]};_z={p:_z,a:_x};_x=_r[0]}while(!", + cs, + ")}" + )); + if(c){ f.c = c; } + if(t){ f.t = t; } + if(b){ f.b = b; } + if(a){ f.a = a; } + return f; + }; +})(); + +/* +For documentation only: + +1) The original recursive version: + +var binrec1 = function(cond, then, before, after){ + var cond = df.lambda(cond), + then = df.lambda(then), + before = df.lambda(before), + after = df.lambda(after); + return function(){ + if(cond.apply(this, arguments)){ + return then.apply(this, arguments); + } + var args = before.apply(this, arguments); + var ret1 = arguments.callee.apply(this, args[0]); + var ret2 = arguments.callee.apply(this, args[1]); + return after.call(this, ret1, ret2, arguments); + }; +}; + +2) The original iterative version (before minification and inlining): + +var binrec2 = function(cond, then, before, after){ + var cond = df.lambda(cond), + then = df.lambda(then), + before = df.lambda(before), + after = df.lambda(after); + return function(){ + var top1, top2, ret, args = arguments; + // first part: start the pump + while(!cond.apply(this, args)){ + ret = before.apply(this, args); + top1 = {prev: top1, args: ret[1]}; + top2 = {prev: top2, args: args}; + args = ret[0]; + } + for(;;){ + // second part: mop up + do{ + ret = then.apply(this, args); + if(!top2){ + return ret; + } + while("ret" in top2){ + ret = after.call(this, top2.ret, ret, top2.args); + if(!(top2 = top2.prev)){ + return ret; + } + } + top2.ret = ret; + args = top1.args; + top1 = top1.prev; + }while(cond.apply(this, args)); + // first part (encore) + do{ + ret = before.apply(this, args); + top1 = {prev: top1, args: ret[1]}; + top2 = {prev: top2, args: args}; + args = ret[0]; + }while(!cond.apply(this, args)); + } + }; +}; + +*/ +}); |
