cacert-testmgr/external/ZendFramework-1.9.5/externals/dojo/dojox/lang/functional/multirec.js
Markus Warg 8398c9048d initially import ZendFramework-1.9.5 into repository
code was modified slightly, so the code differs from the original downloadable 1.9.5 version
2010-03-31 10:12:32 +02:00

164 lines
5.1 KiB
JavaScript

dojo.provide("dojox.lang.functional.multirec");
dojo.require("dojox.lang.functional.lambda");
dojo.require("dojox.lang.functional.util");
// This module provides recursion combinators:
// - a multi-way 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", _y_r_y_o = ["_y.r", "_y.o"];
df.multirec = function(
/*Function|String|Array*/ cond,
/*Function|String|Array*/ then,
/*Function|String|Array*/ before,
/*Function|String|Array*/ after){
// summary:
// Generates a function for the multi-way 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. Each member of the array should be
// an array of parameters. The length of it defines how many times
// the generated function is called recursively.
// above:
// The lambda expression, which is called after the recursive step.
// It accepts two parameters: the array of 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, _y_r_y_o, add2dict);
}else{
a = df.lambda(after);
as = "_a.call(this, _y.r, _y.o)";
dict2["_a=_t.a"] = 1;
}
var locals1 = df.keys(dict1), locals2 = df.keys(dict2),
f = new Function([], "var _y={a:arguments},_x,_r,_z,_i".concat( // Function
locals1.length ? "," + locals1.join(",") : "",
locals2.length ? ",_t=arguments.callee," + locals2.join(",") : "",
t ? (locals2.length ? ",_t=_t.t" : "_t=arguments.callee.t") : "",
";for(;;){for(;;){if(_y.o){_r=",
as,
";break}_x=_y.a;if(",
cs,
"){_r=",
ts,
";break}_y.o=_x;_x=",
bs,
";_y.r=[];_z=_y;for(_i=_x.length-1;_i>=0;--_i){_y={p:_y,a:_x[_i],z:_z}}}if(!(_z=_y.z)){return _r}_z.r.push(_r);_y=_y.p}"
));
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 multirec1 = 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),
ret = new Array(args.length);
for(var i = 0; i < args.length; ++i){
ret[i] = arguments.callee.apply(this, args[i]);
}
return after.call(this, ret, arguments);
};
};
2) The original iterative version (before minification and inlining):
var multirec2 = 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 top = {args: arguments}, args, ret, parent, i;
for(;;){
for(;;){
if(top.old){
ret = after.call(this, top.ret, top.old);
break;
}
args = top.args;
if(cond.apply(this, args)){
ret = then.apply(this, args);
break;
}
top.old = args;
args = before.apply(this, args);
top.ret = [];
parent = top;
for(i = args.length - 1; i >= 0; --i){
top = {prev: top, args: args[i], parent: parent};
}
}
if(!(parent = top.parent)){
return ret;
}
parent.ret.push(ret);
top = top.prev;
}
};
};
*/