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Diffstat (limited to 'framework/Web/Javascripts/extended/functional.js')
| -rw-r--r-- | framework/Web/Javascripts/extended/functional.js | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/framework/Web/Javascripts/extended/functional.js b/framework/Web/Javascripts/extended/functional.js new file mode 100644 index 00000000..2ff0f4a3 --- /dev/null +++ b/framework/Web/Javascripts/extended/functional.js @@ -0,0 +1,171 @@ +/**
+FUNCTIONAL
+by Caio Chassot (http://v2studio.com/k/code/)
+*/
+
+/**
+ * this is used internally by each, map, combine, filter and reduce to accept
+ * strings as functions.
+ *
+ * if <b>fn</b> does not contain a return statement, a return keyword will be added
+ * before the last statement. the last statement is determined by removing the
+ * trailing semicolon (';') (if it exists) and then searching for the last
+ * semicolon, hence, caveats may apply (i.e. if the last statement has a
+ * string or regex containing the ';' character things will go wrong)
+ * @param args a string of comma separated names of the function arguments
+ * @param fn the function body
+ */
+function __strfn(args, fn) {
+ /**
+ * Internal function. Do not call it directly.
+ */
+ function quote(s) { return '"' + s.replace(/"/g,'\\"') + '"' }
+ if (!/\breturn\b/.test(fn)) {
+ fn = fn.replace(/;\s*$/, '');
+ fn = fn.insert(fn.lastIndexOf(';')+1, ' return ');
+ }
+ return eval('new Function('
+ + map(args.split(/\s*,\s*/), quote).join()
+ + ','
+ + quote(fn)
+ + ')'
+ );
+}
+
+
+/**
+ * traverses <b>list</b>, applying <b>fn</b> to each item of <b>list</b>.
+ * see doc for <b>__strfn</b> for peculiarities about passing strings for <b>fn</b>
+ *
+ * <b>each</b> provides a safe way for traversing only an array's indexed items,
+ * ignoring its other properties. (as opposed to how for-in works)
+ * @param list anything that can be indexed and has a <b>length</b> property. usually an array.
+ * @param fn either a function, or a string containing a function body,
+ * in which case the name of the paremeters passed to it will be
+ * 'item', 'idx' and 'list'.
+ * @see #__strfn
+ */
+function each(list, fn) {
+ if (typeof(fn)=='string') return each(list, __strfn('item,idx,list', fn));
+ for (var i=0; i < list.length; i++) fn(list[i], i, list);
+}
+
+
+/**
+ * traverses <b>list</b>, applying <b>fn</b> to each item of <b>list</b>, returning an array
+ of values returned by <b>fn</b>
+
+ parameters work the same as for <b>each</b>, same <b>__strfn</b> caveats apply
+
+ if <b>fn</b> is not provided, the list item is returned itself. this is an easy
+ way to transform fake arrays (e.g. the arguments object of a function or
+ nodeList objects) into real javascript arrays.
+ e.g.: args = map(arguments)
+
+ If you don't care about map's return value, you should use <b>each</b>
+
+ this is a simplified version of python's map. parameter order is different,
+ only a single list (array) is accepted, and the parameters passed to [fn]
+ are different:
+ [fn] takes the current item, then, optionally, the current index and a
+ reference to the list (so that [fn] can modify list)
+ see <b>combine</b> if you want to pass multiple lists
+ */
+function map(list, fn) {
+ if (typeof(fn)=='string') return map(list, __strfn('item,idx,list', fn));
+
+ var result = [];
+ fn = fn || function(v) {return v};
+ for (var i=0; i < list.length; i++) result.push(fn(list[i], i, list));
+ return result;
+}
+
+
+/**
+ * combine will traverse all lists concurrently, passing each row if items as
+ parameters to <b>fn</b>
+ if <b>fn</b> is not provided, a function that returns a list containing each
+ item in the row is used.
+ if a list is smaller than the other, <b>null</b> is used in place of its missing
+ items
+ * @param list one or more lists (see <b>each</b> for definition of a list)
+ * @param fn Similar s <b>each</b> or <b>map</b>, a function or a string containing
+ a function body.
+ if a string is used, the name of parameters passed to the
+ created function will be the lowercase alphabet letters, in
+ order: a,b,c...
+ same <b>__strfn</b> caveats apply
+ * @see #each
+ * @see #__strfn
+ * @return an array of the values returned by calling <b>fn</b> for each row of items
+ *//*
+function combine() {
+ var args = map(arguments);
+ var lists = map(args.slice(0,-1),'map(item)');
+ var fn = args.last();
+ var toplen = map(lists, "item.length").max();
+ var vals = [];
+
+ if (!fn) fn = function(){return map(arguments)};
+ if (typeof fn == 'string') {
+ if (lists.length > 26) throw 'string functions can take at most 26 lists';
+ var a = 'a'.charCodeAt(0);
+ fn = __strfn(map(range(a, a+lists.length),'String.fromCharCode(item)').join(','), fn);
+ }
+
+ map(lists, function(li) {
+ while (li.length < toplen) li.push(null);
+ map(li, function(item,ix){
+ if (ix < vals.length) vals[ix].push(item);
+ else vals.push([item]);
+ });
+ });
+
+ return map(vals, function(val) { return fn.apply(fn, val) });
+}
+
+/**
+ * returns an array of items in <b>list</b> for which <b>fn(item)</b> is true
+
+ parameters work the same as for <b>each</b>, same <b>__strfn</b> caveats apply
+
+ if <b>fn</b> is not specified the items are evaluated themselves, that is,
+ filter will return an array of the items in <b>list</b> which evaluate to true
+
+ this is a similar to python's filter, but parameter order is inverted
+ *//*
+function filter(list, fn) {
+ if (typeof(fn)=='string') return filter(list, __strfn('item,idx,list', fn));
+
+ var result = [];
+ fn = fn || function(v) {return v};
+ map(list, function(item,idx,list) { if (fn(item,idx,list)) result.push(item) } );
+ return result;
+}
+
+/**
+ * similar to python's reduce. paremeter order inverted...
+ * @param list see doc for <b>each</b> to learn more about it
+ * @param initial TODO
+ * @param fn similar to <b>each</b> too, but in the case where it's a string,
+ the name of the paremeters passed to it will be 'a' and 'b'
+ same <b>__strfn</b> caveats apply
+ *//*
+function reduce(list, initial, fn) {
+ if (undef(fn)) {
+ fn = initial;
+ // explicit <b>window</b> object so browsers that do not have an <b>undefined</b>
+ //keyword will evaluate to the (hopefully) undefined parameter
+ //<b>undefined</b> of <b>window</b>
+ initial = window.undefined;
+ }
+ if (typeof(fn)=='string') return reduce(list, initial, __strfn('a,b', fn));
+ if (isdef(initial)) list.splice(0,0,initial);
+ if (list.length===0) return false;
+ if (list.length===1) return list[0];
+ var result = list[0];
+ var i = 1;
+ while(i<list.length) result = fn(result,list[i++]);
+ return result;
+}*/
+
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