iter.js

Ajax下日志框架

        var self = MochiKit.Iter;
        iterable = self.iter(iterable);
        var rval = [];
        try {
            while (true) {
                rval.push(iterable.next());
            }
        } catch (e) {
            if (e != self.StopIteration) {
                throw e;
            }
            return rval;
        }
        // mozilla warnings aren't too bright
        return undefined;
    },

        
    reduce: function (fn, iterable, /* optional */initial) {
        var i = 0;
        var x = initial;
        var self = MochiKit.Iter;
        iterable = self.iter(iterable);
        if (arguments.length < 3) {
            try {
                x = iterable.next();
            } catch (e) {
                if (e == self.StopIteration) {
                    e = new TypeError("reduce() of empty sequence with no initial value");
                }
                throw e;
            }
            i++;
        }
        try {
            while (true) {
                x = fn(x, iterable.next());
            }
        } catch (e) {
            if (e != self.StopIteration) {
                throw e;
            }
        }
        return x;
    },

    range: function (/* [start,] stop[, step] */) {
        var start = 0;
        var stop = 0;
        var step = 1;
        if (arguments.length == 1) {
            stop = arguments[0];
        } else if (arguments.length == 2) {
            start = arguments[0];
            stop = arguments[1];
        } else if (arguments.length == 3) {
            start = arguments[0];
            stop = arguments[1];
            step = arguments[2];
        } else {
            throw new TypeError("range() takes 1, 2, or 3 arguments!");
        }
        if (step === 0) {
            throw new TypeError("range() step must not be 0");
        }
        return {
            next: function () {
                if ((step > 0 && start >= stop) || (step < 0 && start <= stop)) {
                    throw MochiKit.Iter.StopIteration;
                }
                var rval = start;
                start += step;
                return rval;
            },
            repr: function () {
                return "range(" + [start, stop, step].join(", ") + ")";
            },
            toString: MochiKit.Base.forwardCall("repr")
        };
    },
            
    sum: function (iterable, start/* = 0 */) {
        var x = start || 0;
        var self = MochiKit.Iter;
        iterable = self.iter(iterable);
        try {
            while (true) {
                x += iterable.next();
            }
        } catch (e) {
            if (e != self.StopIteration) {
                throw e;
            }
        }
        return x;
    },
            
    exhaust: function (iterable) {
        var self = MochiKit.Iter;
        iterable = self.iter(iterable);
        try {
            while (true) {
                iterable.next();
            }
        } catch (e) {
            if (e != self.StopIteration) {
                throw e;
            }
        }
    },

    forEach: function (iterable, func, /* optional */self) {
        var m = MochiKit.Base;
        if (arguments.length > 2) {
            func = m.bind(func, self);
        }
        // fast path for array
        if (m.isArrayLike(iterable)) {
            try {
                for (var i = 0; i < iterable.length; i++) {
                    func(iterable[i]);
                }
            } catch (e) {
                if (e != MochiKit.Iter.StopIteration) {
                    throw e;
                }
            }
        } else {
            self = MochiKit.Iter;
            self.exhaust(self.imap(func, iterable));
        }
    },

    every: function (iterable, func) {
        var self = MochiKit.Iter;
        try {
            self.ifilterfalse(func, iterable).next();
            return false;
        } catch (e) {
            if (e != self.StopIteration) {
                throw e;
            }
            return true;
        }
    },

    sorted: function (iterable, /* optional */cmp) {
        var rval = MochiKit.Iter.list(iterable);
        if (arguments.length == 1) {
            cmp = MochiKit.Base.compare;
        }
        rval.sort(cmp);
        return rval;
    },

    reversed: function (iterable) {
        var rval = MochiKit.Iter.list(iterable);
        rval.reverse();
        return rval;
    },

    some: function (iterable, func) {
        var self = MochiKit.Iter;
        try {
            self.ifilter(func, iterable).next();
            return true;
        } catch (e) {
            if (e != self.StopIteration) {
                throw e;
            }
            return false;
        }
    },

    iextend: function (lst, iterable) {
        if (MochiKit.Base.isArrayLike(iterable)) {
            // fast-path for array-like
            for (var i = 0; i < iterable.length; i++) {
                lst.push(iterable[i]);
            }
        } else {
            var self = MochiKit.Iter;
            iterable = self.iter(iterable);
            try {
                while (true) {
                    lst.push(iterable.next());
                }
            } catch (e) {
                if (e != self.StopIteration) {
                    throw e;
                }
            }
        }
        return lst;
    },

    groupby: function(iterable, /* optional */ keyfunc) {
        var m = MochiKit.Base;
        var self = MochiKit.Iter;
        if (arguments.length < 2) {
            keyfunc = m.operator.identity;
        }
        iterable = self.iter(iterable);

        // shared
        var pk = undefined;
        var k = undefined;
        var v;

        function fetch() {
            v = iterable.next();
            k = keyfunc(v);
        };

        function eat() {
            var ret = v;
            v = undefined;
            return ret;
        };

        var first = true;
        return {
            repr: function () { return "groupby(...)"; },
            next: function() {
                // iterator-next

                // iterate until meet next group
                while (k == pk) {
                    fetch();
                    if (first) {
                        first = false;
                        break;
                    }
                }
                pk = k;
                return [k, {
                    next: function() {
                        // subiterator-next
                        if (v == undefined) { // Is there something to eat?
                            fetch();
                        }
                        if (k != pk) {
                            throw self.StopIteration;
                        }
                        return eat();
                    }
                }];
            }
        };
    },

    groupby_as_array: function (iterable, /* optional */ keyfunc) {
        var m = MochiKit.Base;
        var self = MochiKit.Iter;
        if (arguments.length < 2) {
            keyfunc = m.operator.identity;
        }

        iterable = self.iter(iterable);
        var result = [];
        var first = true;
        var prev_key;
        while (true) {
            try {
                var value = iterable.next();
                var key = keyfunc(value);
            } catch (e) {
                if (e == self.StopIteration) {
                    break;
                }
                throw e;
            }
            if (first || key != prev_key) {
                var values = [];
                result.push([key, values]);
            }
            values.push(value);
            first = false;
            prev_key = key;
        }
        return result;
    },

    arrayLikeIter: function (iterable) {
        var i = 0;
        return {
            repr: function () { return "arrayLikeIter(...)"; },
            toString: MochiKit.Base.forwardCall("repr"),
            next: function () {
                if (i >= iterable.length) {
                    throw MochiKit.Iter.StopIteration;
                }
                return iterable[i++];
            }
        };
    },

    hasIterateNext: function (iterable) {
        return (iterable && typeof(iterable.iterateNext) == "function");
    },

    iterateNextIter: function (iterable) {
        return {
            repr: function () { return "iterateNextIter(...)"; },
            toString: MochiKit.Base.forwardCall("repr"),
            next: function () {
                var rval = iterable.iterateNext();
                if (rval === null || rval === undefined) {
                    throw MochiKit.Iter.StopIteration;
                }
                return rval;
            }
        };
    }
});


MochiKit.Iter.EXPORT_OK = [
    "iteratorRegistry",
    "arrayLikeIter",
    "hasIterateNext",
    "iterateNextIter",
];

MochiKit.Iter.EXPORT = [
    "StopIteration",
    "registerIteratorFactory",
    "iter",
    "count",
    "cycle",
    "repeat",
    "next",
    "izip",
    "ifilter",
    "ifilterfalse",
    "islice",
    "imap",
    "applymap",
    "chain",
    "takewhile",
    "dropwhile",
    "tee",
    "list",
    "reduce",
    "range",
    "sum",
    "exhaust",
    "forEach",
    "every",
    "sorted",
    "reversed",
    "some",
    "iextend",
    "groupby",
    "groupby_as_array"
];

MochiKit.Iter.__new__ = function () {
    var m = MochiKit.Base;
    this.StopIteration = new m.NamedError("StopIteration");
    this.iteratorRegistry = new m.AdapterRegistry();
    // Register the iterator factory for arrays
    this.registerIteratorFactory(
        "arrayLike",
        m.isArrayLike,
        this.arrayLikeIter
    );

    this.registerIteratorFactory(
        "iterateNext",
        this.hasIterateNext,
        this.iterateNextIter
    );

    this.EXPORT_TAGS = {
        ":common": this.EXPORT,
        ":all": m.concat(this.EXPORT, this.EXPORT_OK)
    };

    m.nameFunctions(this);
        
};

MochiKit.Iter.__new__();

//
// XXX: Internet Explorer blows
//
if (!MochiKit.__compat__) {
    reduce = MochiKit.Iter.reduce;
}

MochiKit.Base._exportSymbols(this, MochiKit.Iter);