add utils.always_new

wrapper allows passing constructors as callbacks, where `new` is required.

IPython/html/static/base/js/utils.js

@@ -1,423 +1,436
 //----------------------------------------------------------------------------
 //  Copyright (C) 2008-2012  The IPython Development Team
 //
 //  Distributed under the terms of the BSD License.  The full license is in
 //  the file COPYING, distributed as part of this software.
 //----------------------------------------------------------------------------
 
 //============================================================================
 // Utilities
 //============================================================================
 IPython.namespace('IPython.utils');
 
 IPython.utils = (function (IPython) {
     "use strict";
 
     //============================================================================
     // Cross-browser RegEx Split
     //============================================================================
 
     // This code has been MODIFIED from the code licensed below to not replace the
     // default browser split.  The license is reproduced here.
 
     // see http://blog.stevenlevithan.com/archives/cross-browser-split for more info:
     /*!
      * Cross-Browser Split 1.1.1
      * Copyright 2007-2012 Steven Levithan <stevenlevithan.com>
      * Available under the MIT License
      * ECMAScript compliant, uniform cross-browser split method
      */
 
     /**
      * Splits a string into an array of strings using a regex or string
      * separator. Matches of the separator are not included in the result array.
      * However, if `separator` is a regex that contains capturing groups,
      * backreferences are spliced into the result each time `separator` is
      * matched. Fixes browser bugs compared to the native
      * `String.prototype.split` and can be used reliably cross-browser.
      * @param {String} str String to split.
      * @param {RegExp|String} separator Regex or string to use for separating
      *     the string.
      * @param {Number} [limit] Maximum number of items to include in the result
      *     array.
      * @returns {Array} Array of substrings.
      * @example
      *
      * // Basic use
      * regex_split('a b c d', ' ');
      * // -> ['a', 'b', 'c', 'd']
      *
      * // With limit
      * regex_split('a b c d', ' ', 2);
      * // -> ['a', 'b']
      *
      * // Backreferences in result array
      * regex_split('..word1 word2..', /([a-z]+)(\d+)/i);
      * // -> ['..', 'word', '1', ' ', 'word', '2', '..']
      */
     var regex_split = function (str, separator, limit) {
         // If `separator` is not a regex, use `split`
         if (Object.prototype.toString.call(separator) !== "[object RegExp]") {
             return split.call(str, separator, limit);
         }
         var output = [],
             flags = (separator.ignoreCase ? "i" : "") +
                     (separator.multiline  ? "m" : "") +
                     (separator.extended   ? "x" : "") + // Proposed for ES6
                     (separator.sticky     ? "y" : ""), // Firefox 3+
             lastLastIndex = 0,
             // Make `global` and avoid `lastIndex` issues by working with a copy
             separator = new RegExp(separator.source, flags + "g"),
             separator2, match, lastIndex, lastLength;
         str += ""; // Type-convert
 
         var compliantExecNpcg = typeof(/()??/.exec("")[1]) === "undefined";
         if (!compliantExecNpcg) {
             // Doesn't need flags gy, but they don't hurt
             separator2 = new RegExp("^" + separator.source + "$(?!\\s)", flags);
         }
         /* Values for `limit`, per the spec:
          * If undefined: 4294967295 // Math.pow(2, 32) - 1
          * If 0, Infinity, or NaN: 0
          * If positive number: limit = Math.floor(limit); if (limit > 4294967295) limit -= 4294967296;
          * If negative number: 4294967296 - Math.floor(Math.abs(limit))
          * If other: Type-convert, then use the above rules
          */
         limit = typeof(limit) === "undefined" ?
             -1 >>> 0 : // Math.pow(2, 32) - 1
             limit >>> 0; // ToUint32(limit)
         while (match = separator.exec(str)) {
             // `separator.lastIndex` is not reliable cross-browser
             lastIndex = match.index + match[0].length;
             if (lastIndex > lastLastIndex) {
                 output.push(str.slice(lastLastIndex, match.index));
                 // Fix browsers whose `exec` methods don't consistently return `undefined` for
                 // nonparticipating capturing groups
                 if (!compliantExecNpcg && match.length > 1) {
                     match[0].replace(separator2, function () {
                         for (var i = 1; i < arguments.length - 2; i++) {
                             if (typeof(arguments[i]) === "undefined") {
                                 match[i] = undefined;
                             }
                         }
                     });
                 }
                 if (match.length > 1 && match.index < str.length) {
                     Array.prototype.push.apply(output, match.slice(1));
                 }
                 lastLength = match[0].length;
                 lastLastIndex = lastIndex;
                 if (output.length >= limit) {
                     break;
                 }
             }
             if (separator.lastIndex === match.index) {
                 separator.lastIndex++; // Avoid an infinite loop
             }
         }
         if (lastLastIndex === str.length) {
             if (lastLength || !separator.test("")) {
                 output.push("");
             }
         } else {
             output.push(str.slice(lastLastIndex));
         }
         return output.length > limit ? output.slice(0, limit) : output;
     };
 
     //============================================================================
     // End contributed Cross-browser RegEx Split
     //============================================================================
 
 
     var uuid = function () {
         // http://www.ietf.org/rfc/rfc4122.txt
         var s = [];
         var hexDigits = "0123456789ABCDEF";
         for (var i = 0; i < 32; i++) {
             s[i] = hexDigits.substr(Math.floor(Math.random() * 0x10), 1);
         }
         s[12] = "4";  // bits 12-15 of the time_hi_and_version field to 0010
         s[16] = hexDigits.substr((s[16] & 0x3) | 0x8, 1);  // bits 6-7 of the clock_seq_hi_and_reserved to 01
 
         var uuid = s.join("");
         return uuid;
     };
 
 
     //Fix raw text to parse correctly in crazy XML
     function xmlencode(string) {
         return string.replace(/\&/g,'&'+'amp;')
             .replace(/</g,'&'+'lt;')
             .replace(/>/g,'&'+'gt;')
             .replace(/\'/g,'&'+'apos;')
             .replace(/\"/g,'&'+'quot;')
             .replace(/`/g,'&'+'#96;');
     }
 
 
     //Map from terminal commands to CSS classes
     var ansi_colormap = {
         "01":"ansibold",
         
         "30":"ansiblack",
         "31":"ansired",
         "32":"ansigreen",
         "33":"ansiyellow",
         "34":"ansiblue",
         "35":"ansipurple",
         "36":"ansicyan",
         "37":"ansigray",
         
         "40":"ansibgblack",
         "41":"ansibgred",
         "42":"ansibggreen",
         "43":"ansibgyellow",
         "44":"ansibgblue",
         "45":"ansibgpurple",
         "46":"ansibgcyan",
         "47":"ansibggray"
     };
     
     function _process_numbers(attrs, numbers) {
         // process ansi escapes
         var n = numbers.shift();
         if (ansi_colormap[n]) {
             if ( ! attrs["class"] ) {
                 attrs["class"] = ansi_colormap[n];
             } else {
                 attrs["class"] += " " + ansi_colormap[n];
             }
         } else if (n == "38" || n == "48") {
             // VT100 256 color or 24 bit RGB
             if (numbers.length < 2) {
                 console.log("Not enough fields for VT100 color", numbers);
                 return;
             }
             
             var index_or_rgb = numbers.shift();
             var r,g,b;
             if (index_or_rgb == "5") {
                 // 256 color
                 var idx = parseInt(numbers.shift());
                 if (idx < 16) {
                     // indexed ANSI
                     // ignore bright / non-bright distinction
                     idx = idx % 8;
                     var ansiclass = ansi_colormap[n[0] + (idx % 8).toString()];
                     if ( ! attrs["class"] ) {
                         attrs["class"] = ansiclass;
                     } else {
                         attrs["class"] += " " + ansiclass;
                     }
                     return;
                 } else if (idx < 232) {
                     // 216 color 6x6x6 RGB
                     idx = idx - 16;
                     b = idx % 6;
                     g = Math.floor(idx / 6) % 6;
                     r = Math.floor(idx / 36) % 6;
                     // convert to rgb
                     r = (r * 51);
                     g = (g * 51);
                     b = (b * 51);
                 } else {
                     // grayscale
                     idx = idx - 231;
                     // it's 1-24 and should *not* include black or white,
                     // so a 26 point scale
                     r = g = b = Math.floor(idx * 256 / 26);
                 }
             } else if (index_or_rgb == "2") {
                 // Simple 24 bit RGB
                 if (numbers.length > 3) {
                     console.log("Not enough fields for RGB", numbers);
                     return;
                 }
                 r = numbers.shift();
                 g = numbers.shift();
                 b = numbers.shift();
             } else {
                 console.log("unrecognized control", numbers);
                 return;
             }
             if (r !== undefined) {
                 // apply the rgb color
                 var line;
                 if (n == "38") {
                     line = "color: ";
                 } else {
                     line = "background-color: ";
                 }
                 line = line + "rgb(" + r + "," + g + "," + b + ");"
                 if ( !attrs["style"] ) {
                     attrs["style"] = line;
                 } else {
                     attrs["style"] += " " + line;
                 }
             }
         }
     }
 
     function ansispan(str) {
         // ansispan function adapted from github.com/mmalecki/ansispan (MIT License)
         // regular ansi escapes (using the table above)
         return str.replace(/\033\[(0?[01]|22|39)?([;\d]+)?m/g, function(match, prefix, pattern) {
             if (!pattern) {
                 // [(01|22|39|)m close spans
                 return "</span>";
             }
             // consume sequence of color escapes
             var numbers = pattern.match(/\d+/g);
             var attrs = {};
             while (numbers.length > 0) {
                 _process_numbers(attrs, numbers);
             }
             
             var span = "<span ";
             for (var attr in attrs) {
                 var value = attrs[attr];
                 span = span + " " + attr + '="' + attrs[attr] + '"';
             }
             return span + ">";
         });
     };
     
     // Transform ANSI color escape codes into HTML <span> tags with css
     // classes listed in the above ansi_colormap object. The actual color used
     // are set in the css file.
     function fixConsole(txt) {
         txt = xmlencode(txt);
         var re = /\033\[([\dA-Fa-f;]*?)m/;
         var opened = false;
         var cmds = [];
         var opener = "";
         var closer = "";
 
         // Strip all ANSI codes that are not color related.  Matches
         // all ANSI codes that do not end with "m".
         var ignored_re = /(?=(\033\[[\d;=]*[a-ln-zA-Z]{1}))\1(?!m)/g;
         txt = txt.replace(ignored_re, "");
         
         // color ansi codes
         txt = ansispan(txt);
         return txt;
     }
 
     // Remove chunks that should be overridden by the effect of
     // carriage return characters
     function fixCarriageReturn(txt) {
         var tmp = txt;
         do {
             txt = tmp;
             tmp = txt.replace(/\r+\n/gm, '\n'); // \r followed by \n --> newline
             tmp = tmp.replace(/^.*\r+/gm, '');  // Other \r --> clear line
         } while (tmp.length < txt.length);
         return txt;
     }
 
     // Locate any URLs and convert them to a anchor tag
     function autoLinkUrls(txt) {
         return txt.replace(/(^|\s)(https?|ftp)(:[^'">\s]+)/gi,
             "$1<a target=\"_blank\" href=\"$2$3\">$2$3</a>");
     }
 
     // some keycodes that seem to be platform/browser independent
     var keycodes = {
                 BACKSPACE:  8,
                 TAB      :  9,
                 ENTER    : 13,
                 SHIFT    : 16,
                 CTRL     : 17,
                 CONTROL  : 17,
                 ALT      : 18,
                 CAPS_LOCK: 20,
                 ESC      : 27,
                 SPACE    : 32,
                 PGUP     : 33,
                 PGDOWN   : 34,
                 END      : 35,
                 HOME     : 36,
                 LEFT_ARROW: 37,
                 LEFTARROW: 37,
                 LEFT     : 37,
                 UP_ARROW : 38,
                 UPARROW  : 38,
                 UP       : 38,
                 RIGHT_ARROW:39,
                 RIGHTARROW:39,
                 RIGHT    : 39,
                 DOWN_ARROW: 40,
                 DOWNARROW: 40,
                 DOWN     : 40,
                 // all three of these keys may be COMMAND on OS X:
                 LEFT_SUPER : 91,
                 RIGHT_SUPER : 92,
                 COMMAND  : 93,
     };
 
 
     var points_to_pixels = function (points) {
         // A reasonably good way of converting between points and pixels.
         var test = $('<div style="display: none; width: 10000pt; padding:0; border:0;"></div>');
         $(body).append(test);
         var pixel_per_point = test.width()/10000;
         test.remove();
         return Math.floor(points*pixel_per_point);
     };
 
+    var always_new = function (constructor) {
+        // wrapper around contructor to avoid requiring `var a = new constructor()`
+        // useful for passing constructors as callbacks,
+        // not for programmer laziness.
+        // from http://programmers.stackexchange.com/questions/118798
+        return function () {
+            var obj = Object.create(constructor.prototype);
+            constructor.apply(obj, arguments);
+            return obj;
+        };
+    };
+
 
     var url_path_join = function () {
         // join a sequence of url components with '/'
         var url = '';
         for (var i = 0; i < arguments.length; i++) {
             if (arguments[i] === '') {
                 continue;
             }
             if (url.length > 0 && url[url.length-1] != '/') {
                 url = url + '/' + arguments[i];
             } else {
                 url = url + arguments[i];
             }
         }
         return url;
     };
 
 
     var splitext = function (filename) {
         // mimic Python os.path.splitext
         // Returns ['base', '.ext']
         var idx = filename.lastIndexOf('.');
         if (idx > 0) {
             return [filename.slice(0, idx), filename.slice(idx)];
         } else {
             return [filename, ''];
         }
     }
 
 
     // http://stackoverflow.com/questions/2400935/browser-detection-in-javascript
     var browser = (function() {
         var N= navigator.appName, ua= navigator.userAgent, tem;
         var M= ua.match(/(opera|chrome|safari|firefox|msie)\/?\s*(\.?\d+(\.\d+)*)/i);
         if (M && (tem= ua.match(/version\/([\.\d]+)/i))!= null) M[2]= tem[1];
         M= M? [M[1], M[2]]: [N, navigator.appVersion,'-?'];
         return M;
     })();
 
 
     return {
         regex_split : regex_split,
         uuid : uuid,
         fixConsole : fixConsole,
         keycodes : keycodes,
         fixCarriageReturn : fixCarriageReturn,
         autoLinkUrls : autoLinkUrls,
         points_to_pixels : points_to_pixels,
         url_path_join : url_path_join,
         splitext : splitext,
+        always_new : always_new,
         browser : browser
     };
 
 }(IPython));