Adding float-no-zero branch hosted build

float-no-zero/closure-library/closure/goog/functions/functions.js

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+// Copyright 2008 The Closure Library Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS-IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+/**
+ * @fileoverview Utilities for creating functions. Loosely inspired by the
+ * java classes: http://go/functions.java and http://go/predicate.java.
+ *
+ * @author nicksantos@google.com (Nick Santos)
+ */
+
+
+goog.provide('goog.functions');
+
+
+/**
+ * Creates a function that always returns the same value.
+ * @param {T} retValue The value to return.
+ * @return {function():T} The new function.
+ * @template T
+ */
+goog.functions.constant = function(retValue) {
+  return function() {
+    return retValue;
+  };
+};
+
+
+/**
+ * Always returns false.
+ * @type {function(...): boolean}
+ */
+goog.functions.FALSE = goog.functions.constant(false);
+
+
+/**
+ * Always returns true.
+ * @type {function(...): boolean}
+ */
+goog.functions.TRUE = goog.functions.constant(true);
+
+
+/**
+ * Always returns NULL.
+ * @type {function(...): null}
+ */
+goog.functions.NULL = goog.functions.constant(null);
+
+
+/**
+ * A simple function that returns the first argument of whatever is passed
+ * into it.
+ * @param {T=} opt_returnValue The single value that will be returned.
+ * @param {...*} var_args Optional trailing arguments. These are ignored.
+ * @return {T} The first argument passed in, or undefined if nothing was passed.
+ * @template T
+ */
+goog.functions.identity = function(opt_returnValue, var_args) {
+  return opt_returnValue;
+};
+
+
+/**
+ * Creates a function that always throws an error with the given message.
+ * @param {string} message The error message.
+ * @return {!Function} The error-throwing function.
+ */
+goog.functions.error = function(message) {
+  return function() {
+    throw Error(message);
+  };
+};
+
+
+/**
+ * Creates a function that throws the given object.
+ * @param {*} err An object to be thrown.
+ * @return {!Function} The error-throwing function.
+ */
+goog.functions.fail = function(err) {
+  return function() {
+    throw err;
+  }
+};
+
+
+/**
+ * Given a function, create a function that keeps opt_numArgs arguments and
+ * silently discards all additional arguments.
+ * @param {Function} f The original function.
+ * @param {number=} opt_numArgs The number of arguments to keep. Defaults to 0.
+ * @return {!Function} A version of f that only keeps the first opt_numArgs
+ *     arguments.
+ */
+goog.functions.lock = function(f, opt_numArgs) {
+  opt_numArgs = opt_numArgs || 0;
+  return function() {
+    return f.apply(this, Array.prototype.slice.call(arguments, 0, opt_numArgs));
+  };
+};
+
+
+/**
+ * Given a function, create a new function that swallows its return value
+ * and replaces it with a new one.
+ * @param {Function} f A function.
+ * @param {T} retValue A new return value.
+ * @return {function(...[?]):T} A new function.
+ * @template T
+ */
+goog.functions.withReturnValue = function(f, retValue) {
+  return goog.functions.sequence(f, goog.functions.constant(retValue));
+};
+
+
+/**
+ * Creates the composition of the functions passed in.
+ * For example, (goog.functions.compose(f, g))(a) is equivalent to f(g(a)).
+ * @param {function(...[?]):T} fn The final function.
+ * @param {...Function} var_args A list of functions.
+ * @return {function(...[?]):T} The composition of all inputs.
+ * @template T
+ */
+goog.functions.compose = function(fn, var_args) {
+  var functions = arguments;
+  var length = functions.length;
+  return function() {
+    var result;
+    if (length) {
+      result = functions[length - 1].apply(this, arguments);
+    }
+
+    for (var i = length - 2; i >= 0; i--) {
+      result = functions[i].call(this, result);
+    }
+    return result;
+  };
+};
+
+
+/**
+ * Creates a function that calls the functions passed in in sequence, and
+ * returns the value of the last function. For example,
+ * (goog.functions.sequence(f, g))(x) is equivalent to f(x),g(x).
+ * @param {...Function} var_args A list of functions.
+ * @return {!Function} A function that calls all inputs in sequence.
+ */
+goog.functions.sequence = function(var_args) {
+  var functions = arguments;
+  var length = functions.length;
+  return function() {
+    var result;
+    for (var i = 0; i < length; i++) {
+      result = functions[i].apply(this, arguments);
+    }
+    return result;
+  };
+};
+
+
+/**
+ * Creates a function that returns true if each of its components evaluates
+ * to true. The components are evaluated in order, and the evaluation will be
+ * short-circuited as soon as a function returns false.
+ * For example, (goog.functions.and(f, g))(x) is equivalent to f(x) && g(x).
+ * @param {...Function} var_args A list of functions.
+ * @return {function(...[?]):boolean} A function that ANDs its component
+ *      functions.
+ */
+goog.functions.and = function(var_args) {
+  var functions = arguments;
+  var length = functions.length;
+  return function() {
+    for (var i = 0; i < length; i++) {
+      if (!functions[i].apply(this, arguments)) {
+        return false;
+      }
+    }
+    return true;
+  };
+};
+
+
+/**
+ * Creates a function that returns true if any of its components evaluates
+ * to true. The components are evaluated in order, and the evaluation will be
+ * short-circuited as soon as a function returns true.
+ * For example, (goog.functions.or(f, g))(x) is equivalent to f(x) || g(x).
+ * @param {...Function} var_args A list of functions.
+ * @return {function(...[?]):boolean} A function that ORs its component
+ *    functions.
+ */
+goog.functions.or = function(var_args) {
+  var functions = arguments;
+  var length = functions.length;
+  return function() {
+    for (var i = 0; i < length; i++) {
+      if (functions[i].apply(this, arguments)) {
+        return true;
+      }
+    }
+    return false;
+  };
+};
+
+
+/**
+ * Creates a function that returns the Boolean opposite of a provided function.
+ * For example, (goog.functions.not(f))(x) is equivalent to !f(x).
+ * @param {!Function} f The original function.
+ * @return {function(...[?]):boolean} A function that delegates to f and returns
+ * opposite.
+ */
+goog.functions.not = function(f) {
+  return function() {
+    return !f.apply(this, arguments);
+  };
+};
+
+
+/**
+ * Generic factory function to construct an object given the constructor
+ * and the arguments. Intended to be bound to create object factories.
+ *
+ * Callers should cast the result to the appropriate type for proper type
+ * checking by the compiler.
+ * @param {!Function} constructor The constructor for the Object.
+ * @param {...*} var_args The arguments to be passed to the constructor.
+ * @return {!Object} A new instance of the class given in {@code constructor}.
+ */
+goog.functions.create = function(constructor, var_args) {
+  /** @constructor */
+  var temp = function() {};
+  temp.prototype = constructor.prototype;
+
+  // obj will have constructor's prototype in its chain and
+  // 'obj instanceof constructor' will be true.
+  var obj = new temp();
+
+  // obj is initialized by constructor.
+  // arguments is only array-like so lacks shift(), but can be used with
+  // the Array prototype function.
+  constructor.apply(obj, Array.prototype.slice.call(arguments, 1));
+  return obj;
+};