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Simplify iteratorTemplate.

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John-David Dalton
2013-12-14 00:29:40 -08:00
parent 60a1374fb4
commit e3b4b2f667
7 changed files with 314 additions and 446 deletions
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260
lodash.js
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@@ -125,21 +125,6 @@
'writable': false
};
/** Used as the data object for `iteratorTemplate` */
var iteratorData = {
'args': '',
'array': null,
'bottom': '',
'firstArg': '',
'init': '',
'keys': null,
'loop': '',
'shadowedProps': null,
'support': null,
'top': '',
'useHas': false
};
/** Used to determine if values are of the language type Object */
var objectTypes = {
'boolean': false,
@@ -890,110 +875,72 @@
* @returns {string} Returns the interpolated text.
*/
var iteratorTemplate = template(
// the `iterable` may be reassigned by the `top` snippet
'var index, iterable = <%= firstArg %>, ' +
// assign the `result` variable an initial value
'result = <%= init %>;\n' +
// exit early if the first argument is falsey
'if (!iterable) return result;\n' +
'var result = <%= init %>;\n' +
// exit early if the first argument is not an object
'if (!(object && objectTypes[typeof object])) return result;\n' +
// add code before the iteration branches
'<%= top %>;' +
// array-like iteration:
'<% if (array) { %>\n' +
'var length = iterable.length; index = -1;\n' +
'if (<%= array %>) {' +
// add support for accessing string characters by index if needed
' <% if (support.unindexedChars) { %>\n' +
' if (isString(iterable)) {\n' +
" iterable = iterable.split('')\n" +
' }' +
' <% } %>\n' +
// iterate over the array-like value
' while (++index < length) {\n' +
// add support for iterating over `arguments` objects if needed
'<% if (support.nonEnumArgs) { %>\n' +
'var length = object.length;\n' +
'if (length && isArguments(object)) {\n' +
' key = -1;\n' +
' while (++key < length) {\n' +
" key += '';\n" +
' <%= loop %>;\n' +
' }\n' +
'}\n' +
'else {' +
// object iteration:
// add support for iterating over `arguments` objects if needed
' <% } else if (support.nonEnumArgs) { %>\n' +
' var length = iterable.length; index = -1;\n' +
' if (length && isArguments(iterable)) {\n' +
' while (++index < length) {\n' +
" index += '';\n" +
' <%= loop %>;\n' +
' }\n' +
' } else {' +
' <% } %>' +
' return result\n' +
'}' +
'<% } %>' +
// avoid iterating over `prototype` properties in older Firefox, Opera, and Safari
' <% if (support.enumPrototypes) { %>\n' +
" var skipProto = typeof iterable == 'function';\n" +
' <% } %>' +
'<% if (support.enumPrototypes) { %>\n' +
"var skipProto = typeof object == 'function';\n" +
'<% } %>' +
// avoid iterating over `Error.prototype` properties in older IE and Safari
' <% if (support.enumErrorProps) { %>\n' +
' var skipErrorProps = iterable === errorProto || iterable instanceof Error;\n' +
' <% } %>' +
'<% if (support.enumErrorProps) { %>\n' +
'var skipErrorProps = object === errorProto || object instanceof Error;\n' +
'<% } %>' +
// define conditions used in the loop
' <%' +
' var conditions = [];' +
' if (support.enumPrototypes) { conditions.push(\'!(skipProto && index == "prototype")\'); }' +
' if (support.enumErrorProps) { conditions.push(\'!(skipErrorProps && (index == "message" || index == "name"))\'); }' +
' %>' +
// iterate own properties using `Object.keys`
' <% if (useHas && keys) { %>\n' +
' var ownIndex = -1,\n' +
' ownProps = keys(iterable),\n' +
' length = ownProps.length;\n\n' +
' while (++ownIndex < length) {\n' +
' index = ownProps[ownIndex];\n<%' +
" if (conditions.length) { %> if (<%= conditions.join(' && ') %>) {\n <% } %>" +
' <%= loop %>;' +
' <% if (conditions.length) { %>\n }<% } %>\n' +
' }' +
'<%' +
'var conditions = [];\n' +
"if (support.enumPrototypes) { conditions.push('!(skipProto && key == \\'prototype\\')'); }\n" +
"if (support.enumErrorProps) { conditions.push('!(skipErrorProps && (key == \\'message\\' || key == \\'name\\'))'); }" +
'%>\n' +
// else using a for-in loop
' <% } else { %>\n' +
' for (index in iterable) {\n<%' +
' if (useHas) { conditions.push("hasOwnProperty.call(iterable, index)"); }' +
" if (conditions.length) { %> if (<%= conditions.join(' && ') %>) {\n <% } %>" +
' <%= loop %>;' +
' <% if (conditions.length) { %>\n }<% } %>\n' +
' }' +
'for (var key in object) {\n<%' +
" if (useHas) { conditions.push('hasOwnProperty.call(object, key)'); }\n" +
" if (conditions.length) { %> if (<%= conditions.join(' && ') %>) {\n <% } %>" +
' <%= loop %>;' +
' <% if (conditions.length) { %>\n }<% } %>\n' +
'}\n' +
// Because IE < 9 can't set the `[[Enumerable]]` attribute of an
// existing property and the `constructor` property of a prototype
// defaults to non-enumerable, Lo-Dash skips the `constructor`
// property when it infers it's iterating over a `prototype` object.
' <% if (support.nonEnumShadows) { %>\n\n' +
' if (iterable !== objectProto) {\n' +
" var ctor = iterable.constructor,\n" +
' isProto = iterable === (ctor && ctor.prototype),\n' +
' className = iterable === stringProto ? stringClass : iterable === errorProto ? errorClass : toString.call(iterable),\n' +
' nonEnum = nonEnumProps[className];\n' +
' <% for (k = 0; k < 7; k++) { %>\n' +
" index = '<%= shadowedProps[k] %>';\n" +
' if ((!(isProto && nonEnum[index]) && hasOwnProperty.call(iterable, index))<%' +
' if (!useHas) { %> || (!nonEnum[index] && iterable[index] !== objectProto[index])<% }' +
' %>) {\n' +
' <%= loop %>;\n' +
' }' +
' <% } %>\n' +
'<% if (support.nonEnumShadows) { %>\n' +
'if (object !== objectProto) {\n' +
" var ctor = object.constructor,\n" +
' isProto = object === (ctor && ctor.prototype),\n' +
' className = object === stringProto ? stringClass : object === errorProto ? errorClass : toString.call(object),\n' +
' nonEnum = nonEnumProps[className];\n' +
' <% for (var index = 0; index < 7; index++) { %>\n' +
" key = '<%= shadowedProps[index] %>';\n" +
' if ((!(isProto && nonEnum[key]) && hasOwnProperty.call(object, key))<%' +
' if (!useHas) { %> || (!nonEnum[key] && object[key] !== objectProto[key])<% }' +
' %>) {\n' +
' <%= loop %>;\n' +
' }' +
' <% } %>' +
' <% } %>' +
' <% if (array || support.nonEnumArgs) { %>\n}<% } %>\n' +
' <% } %>\n' +
'}' +
'<% } %>\n' +
// add code to the bottom of the iteration function
'<%= bottom %>;\n' +
// finally, return the `result`
'return result'
);
@@ -1301,6 +1248,41 @@
return result;
}
/**
* Iterates `arguments` objects, arrays, objects, and strings consistently
* across environments, executing the callback for each element in the
* collection. The callback is bound to `thisArg` and invoked with three
* arguments; (value, index|key, collection). Callbacks may exit iteration
* early by explicitly returning `false`.
*
* @private
* @param {Array|Object|string} collection The collection to iterate over.
* @param {Function} [callback=identity] The function called per iteration.
* @param {*} [thisArg] The `this` binding of `callback`.
* @returns {Array|Object|string} Returns `collection`.
*/
function baseEach(collection, callback, thisArg) {
var index = -1,
iterable = collection,
length = collection ? collection.length : 0;
callback = callback && typeof thisArg == 'undefined' ? callback : baseCreateCallback(callback, thisArg, 3);
if (typeof length == 'number') {
if (support.unindexedChars && isString(iterable)) {
iterable = iterable.split('');
}
while (++index < length) {
if (callback(iterable[index], index, collection) === false) {
break;
}
}
} else {
forOwn(collection, callback);
}
return collection;
}
/**
* The base implementation of `_.flatten` without support for callback
* shorthands or `thisArg` binding.
@@ -1757,48 +1739,28 @@
* Creates compiled iteration functions.
*
* @private
* @param {...Object} [options] The compile options object(s).
* @param {string} [options.array] Code to determine if the iterable is an array or array-like.
* @param {boolean} [options.useHas] Specify using `hasOwnProperty` checks in the object loop.
* @param {Function} [options.keys] A reference to `_.keys` for use in own property iteration.
* @param {Object} [options] The compile options object.
* @param {string} [options.args] A comma separated string of iteration function arguments.
* @param {string} [options.top] Code to execute before the iteration branches.
* @param {string} [options.loop] Code to execute in the object loop.
* @param {string} [options.bottom] Code to execute after the iteration branches.
* @param {boolean} [options.useHas] Specify using `hasOwnProperty` checks in the object loop.
* @returns {Function} Returns the compiled function.
*/
function createIterator() {
// data properties
iteratorData.shadowedProps = shadowedProps;
iteratorData.support = support;
// iterator options
iteratorData.array = iteratorData.bottom = iteratorData.loop = iteratorData.top = '';
iteratorData.init = 'iterable';
iteratorData.useHas = true;
// merge options into a template data object
for (var object, index = 0; object = arguments[index]; index++) {
for (var key in object) {
iteratorData[key] = object[key];
}
}
var args = iteratorData.args;
iteratorData.firstArg = /^[^,]+/.exec(args)[0];
function createIterator(options) {
options.shadowedProps = shadowedProps;
options.support = support;
// create the function factory
var factory = Function(
'baseCreateCallback, errorClass, errorProto, hasOwnProperty, ' +
'indicatorObject, isArguments, isArray, isString, keys, objectProto, ' +
'objectTypes, nonEnumProps, stringClass, stringProto, toString',
'return function(' + args + ') {\n' + iteratorTemplate(iteratorData) + '\n}'
'baseCreateCallback, errorClass, errorProto, hasOwnProperty, isArguments, ' +
'objectProto, objectTypes, nonEnumProps, stringClass, stringProto, toString',
'return function(' + options.args + ') {\n' + iteratorTemplate(options) + '\n}'
);
// return the compiled function
return factory(
baseCreateCallback, errorClass, errorProto, hasOwnProperty,
indicatorObject, isArguments, isArray, isString, iteratorData.keys, objectProto,
objectTypes, nonEnumProps, stringClass, stringProto, toString
baseCreateCallback, errorClass, errorProto, hasOwnProperty, isArguments,
objectProto, objectTypes, nonEnumProps, stringClass, stringProto, toString
);
}
@@ -1965,7 +1927,8 @@
'args': 'object',
'init': '[]',
'top': 'if (!(objectTypes[typeof object])) return result',
'loop': 'result.push(index)'
'loop': 'result.push(key)',
'useHas': true
});
/**
@@ -1992,15 +1955,6 @@
return nativeKeys(object);
};
/** Reusable iterator options shared by `each`, `forIn`, and `forOwn` */
var eachIteratorOptions = {
'args': 'collection, callback, thisArg',
'top': "callback = callback && typeof thisArg == 'undefined' ? callback : baseCreateCallback(callback, thisArg, 3)",
'array': "typeof length == 'number'",
'keys': keys,
'loop': 'if (callback(iterable[index], index, collection) === false) return result'
};
/**
* Used to convert characters to HTML entities:
*
@@ -2024,22 +1978,6 @@
var reEscapedHtml = RegExp('(' + keys(htmlUnescapes).join('|') + ')', 'g'),
reUnescapedHtml = RegExp('[' + keys(htmlEscapes).join('') + ']', 'g');
/**
* A function compiled to iterate `arguments` objects, arrays, objects, and
* strings consistenly across environments, executing the callback for each
* element in the collection. The callback is bound to `thisArg` and invoked
* with three arguments; (value, index|key, collection). Callbacks may exit
* iteration early by explicitly returning `false`.
*
* @private
* @type Function
* @param {Array|Object|string} collection The collection to iterate over.
* @param {Function} [callback=identity] The function called per iteration.
* @param {*} [thisArg] The `this` binding of `callback`.
* @returns {Array|Object|string} Returns `collection`.
*/
var baseEach = createIterator(eachIteratorOptions);
/*--------------------------------------------------------------------------*/
/**
@@ -2051,7 +1989,6 @@
*
* @static
* @memberOf _
* @type Function
* @alias extend
* @category Objects
* @param {Object} object The destination object.
@@ -2237,7 +2174,6 @@
*
* @static
* @memberOf _
* @type Function
* @category Objects
* @param {Object} object The destination object.
* @param {...Object} [source] The source objects.
@@ -2410,9 +2346,11 @@
* });
* // => logs 'x', 'y', and 'move' (property order is not guaranteed across environments)
*/
var forIn = createIterator(eachIteratorOptions, {
'top': 'if (!objectTypes[typeof iterable]) return result;\n' + eachIteratorOptions.top,
'array': false,
var forIn = createIterator({
'args': 'object, callback, thisArg',
'init': 'object',
'top': "callback = callback && typeof thisArg == 'undefined' ? callback : baseCreateCallback(callback, thisArg, 3)",
'loop': 'if (callback(object[key], key, object) === false) return result',
'useHas': false
});
@@ -2469,7 +2407,6 @@
*
* @static
* @memberOf _
* @type Function
* @category Objects
* @param {Object} object The object to iterate over.
* @param {Function} [callback=identity] The function called per iteration.
@@ -3768,7 +3705,7 @@
} else if (support.unindexedChars && isString(collection)) {
iterable = collection.split('');
}
baseEach(collection, function(value, key, collection) {
baseEach(iterable, function(value, key) {
key = props ? props[--length] : --length;
return callback(iterable[key], key, collection);
});
@@ -7238,7 +7175,6 @@
}
// add pseudo private property to be used and removed during the build process
lodash._baseEach = baseEach;
lodash._iteratorTemplate = iteratorTemplate;
lodash._shimKeys = shimKeys;