diff options
| author | Tristan Zur <tzur@web.web.ccwn.org> | 2014-03-27 22:27:47 +0100 |
|---|---|---|
| committer | Tristan Zur <tzur@web.web.ccwn.org> | 2014-03-27 22:27:47 +0100 |
| commit | b62676ca5d3d6f6ba3f019ea3f99722e165a98d8 (patch) | |
| tree | 86722cb80f07d4569f90088eeaea2fc2f6e2ef94 /js/dojo-1.6/dojox/lang/functional/linrec.js | |
Diffstat (limited to 'js/dojo-1.6/dojox/lang/functional/linrec.js')
| -rw-r--r-- | js/dojo-1.6/dojox/lang/functional/linrec.js | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/js/dojo-1.6/dojox/lang/functional/linrec.js b/js/dojo-1.6/dojox/lang/functional/linrec.js new file mode 100644 index 0000000..cea5114 --- /dev/null +++ b/js/dojo-1.6/dojox/lang/functional/linrec.js @@ -0,0 +1,154 @@ +/*
+ Copyright (c) 2004-2011, The Dojo Foundation All Rights Reserved.
+ Available via Academic Free License >= 2.1 OR the modified BSD license.
+ see: http://dojotoolkit.org/license for details
+*/
+
+
+if(!dojo._hasResource["dojox.lang.functional.linrec"]){ //_hasResource checks added by build. Do not use _hasResource directly in your code.
+dojo._hasResource["dojox.lang.functional.linrec"] = true;
+dojo.provide("dojox.lang.functional.linrec");
+
+dojo.require("dojox.lang.functional.lambda");
+dojo.require("dojox.lang.functional.util");
+
+// This module provides recursion combinators:
+// - a linear 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", _r_y_a = ["_r", "_y.a"];
+
+ df.linrec = function(
+ /*Function|String|Array*/ cond,
+ /*Function|String|Array*/ then,
+ /*Function|String|Array*/ before,
+ /*Function|String|Array*/ after){
+ // summary:
+ // Generates a function for the linear 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, which is used to call
+ // the generated function recursively.
+ // above:
+ // The lambda expression, which is called after the recursive step.
+ // It accepts two parameters: the returned value from the recursive step, 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.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, _r_y_a, add2dict);
+ }else{
+ a = df.lambda(after);
+ as = "_a.call(this, _r, _y.a)";
+ dict2["_a=_t.a"] = 1;
+ }
+ var locals1 = df.keys(dict1), locals2 = df.keys(dict2),
+ f = new Function([], "var _x=arguments,_y,_r".concat( // Function
+ locals1.length ? "," + locals1.join(",") : "",
+ locals2.length ? ",_t=_x.callee," + locals2.join(",") : t ? ",_t=_x.callee" : "",
+ ";for(;!",
+ cs,
+ ";_x=",
+ bs,
+ "){_y={p:_y,a:_x}}_r=",
+ ts,
+ ";for(;_y;_y=_y.p){_r=",
+ as,
+ "}return _r"
+ ));
+ 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 linrec1 = 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 ret = arguments.callee.apply(this, args);
+ return after.call(this, ret, arguments);
+ };
+};
+
+2) The original iterative version (before minification and inlining):
+
+var linrec2 = 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 args = arguments, top, ret;
+ // 1st part
+ for(; !cond.apply(this, args); args = before.apply(this, args)){
+ top = {prev: top, args: args};
+ }
+ ret = then.apply(this, args);
+ //2nd part
+ for(; top; top = top.prev){
+ ret = after.call(this, ret, top.args);
+ }
+ return ret;
+ };
+};
+
+*/
+
+}
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