godoc/static/godocs.js - tools - Git at Google

 // Copyright 2012 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.

 /* A little code to ease navigation of these documents.
  *
  * On window load we:
  *  + Generate a table of contents (generateTOC)
  *  + Bind foldable sections (bindToggles)
  *  + Bind links to foldable sections (bindToggleLinks)
  */

 (function() {
 'use strict';

 // Mobile-friendly topbar menu
 $(function() {
   var menu = $('#menu');
   var menuButton = $('#menu-button');
   var menuButtonArrow = $('#menu-button-arrow');
   menuButton.click(function(event) {
     menu.toggleClass('menu-visible');
     menuButtonArrow.toggleClass('vertical-flip');
     event.preventDefault();
     return false;
   });
 });

 /* Generates a table of contents: looks for h2 and h3 elements and generates
  * links. "Decorates" the element with id=="nav" with this table of contents.
  */
 function generateTOC() {
   if ($('#manual-nav').length > 0) {
     return;
   }

   var nav = $('#nav');
   if (nav.length === 0) {
     return;
   }

   var toc_items = [];
   $(nav).nextAll('h2, h3').each(function() {
     var node = this;
     if (node.id == '')
       node.id = 'tmp_' + toc_items.length;
     var link = $('<a/>').attr('href', '#' + node.id).text($(node).text());
     var item;
     if ($(node).is('h2')) {
       item = $('<dt/>');
     } else { // h3
       item = $('<dd class="indent"/>');
     }
     item.append(link);
     toc_items.push(item);
   });
   if (toc_items.length <= 1) {
     return;
   }

   var dl1 = $('<dl/>');
   var dl2 = $('<dl/>');

   var split_index = (toc_items.length / 2) + 1;
   if (split_index < 8) {
     split_index = toc_items.length;
   }
   for (var i = 0; i < split_index; i++) {
     dl1.append(toc_items[i]);
   }
   for (/* keep using i */; i < toc_items.length; i++) {
     dl2.append(toc_items[i]);
   }

   var tocTable = $('<table class="unruled"/>').appendTo(nav);
   var tocBody = $('<tbody/>').appendTo(tocTable);
   var tocRow = $('<tr/>').appendTo(tocBody);

   // 1st column
   $('<td class="first"/>').appendTo(tocRow).append(dl1);
   // 2nd column
   $('<td/>').appendTo(tocRow).append(dl2);
 }

 function bindToggle(el) {
   $('.toggleButton', el).click(function() {
     if ($(this).closest(".toggle, .toggleVisible")[0] != el) {
       // Only trigger the closest toggle header.
       return;
     }

     if ($(el).is('.toggle')) {
       $(el).addClass('toggleVisible').removeClass('toggle');
     } else {
       $(el).addClass('toggle').removeClass('toggleVisible');
     }
   });
 }

 function bindToggles(selector) {
   $(selector).each(function(i, el) {
     bindToggle(el);
   });
 }

 function bindToggleLink(el, prefix) {
   $(el).click(function() {
     var href = $(el).attr('href');
     var i = href.indexOf('#'+prefix);
     if (i < 0) {
       return;
     }
     var id = '#' + prefix + href.slice(i+1+prefix.length);
     if ($(id).is('.toggle')) {
       $(id).find('.toggleButton').first().click();
     }
   });
 }
 function bindToggleLinks(selector, prefix) {
   $(selector).each(function(i, el) {
     bindToggleLink(el, prefix);
   });
 }

 function setupDropdownPlayground() {
   if (!$('#page').is('.wide')) {
     return; // don't show on front page
   }
   var button = $('#playgroundButton');
   var div = $('#playground');
   var setup = false;
   button.toggle(function() {
     button.addClass('active');
     div.show();
     if (setup) {
       return;
     }
     setup = true;
     playground({
       'codeEl': $('.code', div),
       'outputEl': $('.output', div),
       'runEl': $('.run', div),
       'fmtEl': $('.fmt', div),
       'shareEl': $('.share', div),
       'shareRedirect': '//play.golang.org/p/'
     });
   },
   function() {
     button.removeClass('active');
     div.hide();
   });
   button.show();
   $('#menu').css('min-width', '+=60');
 }

 function setupInlinePlayground() {
 	'use strict';
 	// Set up playground when each element is toggled.
 	$('div.play').each(function (i, el) {
 		// Set up playground for this example.
 		var setup = function() {
 			var code = $('.code', el);
 			playground({
 				'codeEl':   code,
 				'outputEl': $('.output', el),
 				'runEl':    $('.run', el),
 				'fmtEl':    $('.fmt', el),
 				'shareEl':  $('.share', el),
 				'shareRedirect': '//play.golang.org/p/'
 			});

 			// Make the code textarea resize to fit content.
 			var resize = function() {
 				code.height(0);
 				var h = code[0].scrollHeight;
 				code.height(h+20); // minimize bouncing.
 				code.closest('.input').height(h);
 			};
 			code.on('keydown', resize);
 			code.on('keyup', resize);
 			code.keyup(); // resize now.
 		};

 		// If example already visible, set up playground now.
 		if ($(el).is(':visible')) {
 			setup();
 			return;
 		}

 		// Otherwise, set up playground when example is expanded.
 		var built = false;
 		$(el).closest('.toggle').click(function() {
 			// Only set up once.
 			if (!built) {
 				setup();
 				built = true;
 			}
 		});
 	});
 }

 // fixFocus tries to put focus to div#page so that keyboard navigation works.
 function fixFocus() {
   var page = $('div#page');
   var topbar = $('div#topbar');
   page.css('outline', 0); // disable outline when focused
   page.attr('tabindex', -1); // and set tabindex so that it is focusable
   $(window).resize(function (evt) {
     // only focus page when the topbar is at fixed position (that is, it's in
     // front of page, and keyboard event will go to the former by default.)
     // by focusing page, keyboard event will go to page so that up/down arrow,
     // space, etc. will work as expected.
     if (topbar.css('position') == "fixed")
       page.focus();
   }).resize();
 }

 function toggleHash() {
   var id = window.location.hash.substring(1);
   // Open all of the toggles for a particular hash.
   var els = $(
     document.getElementById(id),
     $('a[name]').filter(function() {
       return $(this).attr('name') == id;
     })
   );

   while (els.length) {
     for (var i = 0; i < els.length; i++) {
       var el = $(els[i]);
       if (el.is('.toggle')) {
         el.find('.toggleButton').first().click();
       }
     }
     els = el.parent();
   }
 }

 function personalizeInstallInstructions() {
   var prefix = '?download=';
   var s = window.location.search;
   if (s.indexOf(prefix) != 0) {
     // No 'download' query string; detect "test" instructions from User Agent.
     if (navigator.platform.indexOf('Win') != -1) {
       $('.testUnix').hide();
       $('.testWindows').show();
     } else {
       $('.testUnix').show();
       $('.testWindows').hide();
     }
     return;
   }

   var filename = s.substr(prefix.length);
   var filenameRE = /^go1\.\d+(\.\d+)?([a-z0-9]+)?\.([a-z0-9]+)(-[a-z0-9]+)?(-osx10\.[68])?\.([a-z.]+)$/;
   $('.downloadFilename').text(filename);
   $('.hideFromDownload').hide();
   var m = filenameRE.exec(filename);
   if (!m) {
     // Can't interpret file name; bail.
     return;
   }

   var os = m[3];
   var ext = m[6];
   if (ext != 'tar.gz') {
     $('#tarballInstructions').hide();
   }
   if (os != 'darwin' || ext != 'pkg') {
     $('#darwinPackageInstructions').hide();
   }
   if (os != 'windows') {
     $('#windowsInstructions').hide();
     $('.testUnix').show();
     $('.testWindows').hide();
   } else {
     if (ext != 'msi') {
       $('#windowsInstallerInstructions').hide();
     }
     if (ext != 'zip') {
       $('#windowsZipInstructions').hide();
     }
     $('.testUnix').hide();
     $('.testWindows').show();
   }

   var download = "https://dl.google.com/go/" + filename;

   var message = $('<p class="downloading">'+
     'Your download should begin shortly. '+
     'If it does not, click <a>this link</a>.</p>');
   message.find('a').attr('href', download);
   message.insertAfter('#nav');

   window.location = download;
 }

 function updateVersionTags() {
   var v = window.goVersion;
   if (/^go[0-9.]+$/.test(v)) {
     $(".versionTag").empty().text(v);
     $(".whereTag").hide();
   }
 }

 function addPermalinks() {
   function addPermalink(source, parent) {
     var id = source.attr("id");
     if (id == "" || id.indexOf("tmp_") === 0) {
       // Auto-generated permalink.
       return;
     }
     if (parent.find("> .permalink").length) {
       // Already attached.
       return;
     }
     parent.append(" ").append($("<a class='permalink'>&#xb6;</a>").attr("href", "#" + id));
   }

   $("#page .container").find("h2[id], h3[id]").each(function() {
     var el = $(this);
     addPermalink(el, el);
   });

   $("#page .container").find("dl[id]").each(function() {
     var el = $(this);
     // Add the anchor to the "dt" element.
     addPermalink(el, el.find("> dt").first());
   });
 }

 $(document).ready(function() {
   generateTOC();
   addPermalinks();
   bindToggles(".toggle");
   bindToggles(".toggleVisible");
   bindToggleLinks(".exampleLink", "example_");
   bindToggleLinks(".overviewLink", "");
   bindToggleLinks(".examplesLink", "");
   bindToggleLinks(".indexLink", "");
   setupDropdownPlayground();
   setupInlinePlayground();
   fixFocus();
   setupTypeInfo();
   setupCallgraphs();
   toggleHash();
   personalizeInstallInstructions();
   updateVersionTags();

   // godoc.html defines window.initFuncs in the <head> tag, and root.html and
   // codewalk.js push their on-page-ready functions to the list.
   // We execute those functions here, to avoid loading jQuery until the page
   // content is loaded.
   for (var i = 0; i < window.initFuncs.length; i++) window.initFuncs[i]();
 });

 // -- analysis ---------------------------------------------------------

 // escapeHTML returns HTML for s, with metacharacters quoted.
 // It is safe for use in both elements and attributes
 // (unlike the "set innerText, read innerHTML" trick).
 function escapeHTML(s) {
     return s.replace(/&/g, '&amp;').
              replace(/\"/g, '&quot;').
              replace(/\'/g, '&#39;').
              replace(/</g, '&lt;').
              replace(/>/g, '&gt;');
 }

 // makeAnchor returns HTML for an <a> element, given an anchorJSON object.
 function makeAnchor(json) {
   var html = escapeHTML(json.Text);
   if (json.Href != "") {
       html = "<a href='" + escapeHTML(json.Href) + "'>" + html + "</a>";
   }
   return html;
 }

 function showLowFrame(html) {
   var lowframe = document.getElementById('lowframe');
   lowframe.style.height = "200px";
   lowframe.innerHTML = "<p style='text-align: left;'>" + html + "</p>\n" +
       "<div onclick='hideLowFrame()' style='position: absolute; top: 0; right: 0; cursor: pointer;'>✘</div>"
 };

 document.hideLowFrame = function() {
   var lowframe = document.getElementById('lowframe');
   lowframe.style.height = "0px";
 }

 // onClickCallers is the onclick action for the 'func' tokens of a
 // function declaration.
 document.onClickCallers = function(index) {
   var data = document.ANALYSIS_DATA[index]
   if (data.Callers.length == 1 && data.Callers[0].Sites.length == 1) {
     document.location = data.Callers[0].Sites[0].Href; // jump to sole caller
     return;
   }

   var html = "Callers of <code>" + escapeHTML(data.Callee) + "</code>:<br/>\n";
   for (var i = 0; i < data.Callers.length; i++) {
     var caller = data.Callers[i];
     html += "<code>" + escapeHTML(caller.Func) + "</code>";
     var sites = caller.Sites;
     if (sites != null && sites.length > 0) {
       html += " at line ";
       for (var j = 0; j < sites.length; j++) {
         if (j > 0) {
           html += ", ";
         }
         html += "<code>" + makeAnchor(sites[j]) + "</code>";
       }
     }
     html += "<br/>\n";
   }
   showLowFrame(html);
 };

 // onClickCallees is the onclick action for the '(' token of a function call.
 document.onClickCallees = function(index) {
   var data = document.ANALYSIS_DATA[index]
   if (data.Callees.length == 1) {
     document.location = data.Callees[0].Href; // jump to sole callee
     return;
   }

   var html = "Callees of this " + escapeHTML(data.Descr) + ":<br/>\n";
   for (var i = 0; i < data.Callees.length; i++) {
     html += "<code>" + makeAnchor(data.Callees[i]) + "</code><br/>\n";
   }
   showLowFrame(html);
 };

 // onClickTypeInfo is the onclick action for identifiers declaring a named type.
 document.onClickTypeInfo = function(index) {
   var data = document.ANALYSIS_DATA[index];
   var html = "Type <code>" + data.Name + "</code>: " +
   "&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<small>(size=" + data.Size + ", align=" + data.Align + ")</small><br/>\n";
   html += implementsHTML(data);
   html += methodsetHTML(data);
   showLowFrame(html);
 };

 // implementsHTML returns HTML for the implements relation of the
 // specified TypeInfoJSON value.
 function implementsHTML(info) {
   var html = "";
   if (info.ImplGroups != null) {
     for (var i = 0; i < info.ImplGroups.length; i++) {
       var group = info.ImplGroups[i];
       var x = "<code>" + escapeHTML(group.Descr) + "</code> ";
       for (var j = 0; j < group.Facts.length; j++) {
         var fact = group.Facts[j];
         var y = "<code>" + makeAnchor(fact.Other) + "</code>";
         if (fact.ByKind != null) {
           html += escapeHTML(fact.ByKind) + " type " + y + " implements " + x;
         } else {
           html += x + " implements " + y;
         }
         html += "<br/>\n";
       }
     }
   }
   return html;
 }


 // methodsetHTML returns HTML for the methodset of the specified
 // TypeInfoJSON value.
 function methodsetHTML(info) {
   var html = "";
   if (info.Methods != null) {
     for (var i = 0; i < info.Methods.length; i++) {
       html += "<code>" + makeAnchor(info.Methods[i]) + "</code><br/>\n";
     }
   }
   return html;
 }

 // onClickComm is the onclick action for channel "make" and "<-"
 // send/receive tokens.
 document.onClickComm = function(index) {
   var ops = document.ANALYSIS_DATA[index].Ops
   if (ops.length == 1) {
     document.location = ops[0].Op.Href; // jump to sole element
     return;
   }

   var html = "Operations on this channel:<br/>\n";
   for (var i = 0; i < ops.length; i++) {
     html += makeAnchor(ops[i].Op) + " by <code>" + escapeHTML(ops[i].Fn) + "</code><br/>\n";
   }
   if (ops.length == 0) {
     html += "(none)<br/>\n";
   }
   showLowFrame(html);
 };

 $(window).load(function() {
     // Scroll window so that first selection is visible.
     // (This means we don't need to emit id='L%d' spans for each line.)
     // TODO(adonovan): ideally, scroll it so that it's under the pointer,
     // but I don't know how to get the pointer y coordinate.
     var elts = document.getElementsByClassName("selection");
     if (elts.length > 0) {
 	elts[0].scrollIntoView()
     }
 });

 // setupTypeInfo populates the "Implements" and "Method set" toggle for
 // each type in the package doc.
 function setupTypeInfo() {
   for (var i in document.ANALYSIS_DATA) {
     var data = document.ANALYSIS_DATA[i];

     var el = document.getElementById("implements-" + i);
     if (el != null) {
       // el != null => data is TypeInfoJSON.
       if (data.ImplGroups != null) {
         el.innerHTML = implementsHTML(data);
         el.parentNode.parentNode.style.display = "block";
       }
     }

     var el = document.getElementById("methodset-" + i);
     if (el != null) {
       // el != null => data is TypeInfoJSON.
       if (data.Methods != null) {
         el.innerHTML = methodsetHTML(data);
         el.parentNode.parentNode.style.display = "block";
       }
     }
   }
 }

 function setupCallgraphs() {
   if (document.CALLGRAPH == null) {
     return
   }
   document.getElementById("pkg-callgraph").style.display = "block";

   var treeviews = document.getElementsByClassName("treeview");
   for (var i = 0; i < treeviews.length; i++) {
     var tree = treeviews[i];
     if (tree.id == null || tree.id.indexOf("callgraph-") != 0) {
       continue;
     }
     var id = tree.id.substring("callgraph-".length);
     $(tree).treeview({collapsed: true, animated: "fast"});
     document.cgAddChildren(tree, tree, [id]);
     tree.parentNode.parentNode.style.display = "block";
   }
 }

 document.cgAddChildren = function(tree, ul, indices) {
   if (indices != null) {
     for (var i = 0; i < indices.length; i++) {
       var li = cgAddChild(tree, ul, document.CALLGRAPH[indices[i]]);
       if (i == indices.length - 1) {
         $(li).addClass("last");
       }
     }
   }
   $(tree).treeview({animated: "fast", add: ul});
 }

 // cgAddChild adds an <li> element for document.CALLGRAPH node cgn to
 // the parent <ul> element ul. tree is the tree's root <ul> element.
 function cgAddChild(tree, ul, cgn) {
    var li = document.createElement("li");
    ul.appendChild(li);
    li.className = "closed";

    var code = document.createElement("code");

    if (cgn.Callees != null) {
      $(li).addClass("expandable");

      // Event handlers and innerHTML updates don't play nicely together,
      // hence all this explicit DOM manipulation.
      var hitarea = document.createElement("div");
      hitarea.className = "hitarea expandable-hitarea";
      li.appendChild(hitarea);

      li.appendChild(code);

      var childUL = document.createElement("ul");
      li.appendChild(childUL);
      childUL.setAttribute('style', "display: none;");

      var onClick = function() {
        document.cgAddChildren(tree, childUL, cgn.Callees);
        hitarea.removeEventListener('click', onClick)
      };
      hitarea.addEventListener('click', onClick);

    } else {
      li.appendChild(code);
    }
    code.innerHTML += "&nbsp;" + makeAnchor(cgn.Func);
    return li
 }

 })();
	// Copyright 2012 The Go Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style
	// license that can be found in the LICENSE file.

	/* A little code to ease navigation of these documents.
	*
	* On window load we:
	* + Generate a table of contents (generateTOC)
	* + Bind foldable sections (bindToggles)
	* + Bind links to foldable sections (bindToggleLinks)
	*/

	(function() {
	'use strict';

	// Mobile-friendly topbar menu
	$(function() {
	var menu = $('#menu');
	var menuButton = $('#menu-button');
	var menuButtonArrow = $('#menu-button-arrow');
	menuButton.click(function(event) {
	menu.toggleClass('menu-visible');
	menuButtonArrow.toggleClass('vertical-flip');
	event.preventDefault();
	return false;
	});
	});

	/* Generates a table of contents: looks for h2 and h3 elements and generates
	* links. "Decorates" the element with id=="nav" with this table of contents.
	*/
	function generateTOC() {
	if ($('#manual-nav').length > 0) {
	return;
	}

	var nav = $('#nav');
	if (nav.length === 0) {
	return;
	}

	var toc_items = [];
	$(nav).nextAll('h2, h3').each(function() {
	var node = this;
	if (node.id == '')
	node.id = 'tmp_' + toc_items.length;
	var link = $('<a/>').attr('href', '#' + node.id).text($(node).text());
	var item;
	if ($(node).is('h2')) {
	item = $('<dt/>');
	} else { // h3
	item = $('<dd class="indent"/>');
	}
	item.append(link);
	toc_items.push(item);
	});
	if (toc_items.length <= 1) {
	return;
	}

	var dl1 = $('<dl/>');
	var dl2 = $('<dl/>');

	var split_index = (toc_items.length / 2) + 1;
	if (split_index < 8) {
	split_index = toc_items.length;
	}
	for (var i = 0; i < split_index; i++) {
	dl1.append(toc_items[i]);
	}
	for (/* keep using i */; i < toc_items.length; i++) {
	dl2.append(toc_items[i]);
	}

	var tocTable = $('<table class="unruled"/>').appendTo(nav);
	var tocBody = $('<tbody/>').appendTo(tocTable);
	var tocRow = $('<tr/>').appendTo(tocBody);

	// 1st column
	$('<td class="first"/>').appendTo(tocRow).append(dl1);
	// 2nd column
	$('<td/>').appendTo(tocRow).append(dl2);
	}

	function bindToggle(el) {
	$('.toggleButton', el).click(function() {
	if ($(this).closest(".toggle, .toggleVisible")[0] != el) {
	// Only trigger the closest toggle header.
	return;
	}

	if ($(el).is('.toggle')) {
	$(el).addClass('toggleVisible').removeClass('toggle');
	} else {
	$(el).addClass('toggle').removeClass('toggleVisible');
	}
	});
	}

	function bindToggles(selector) {
	$(selector).each(function(i, el) {
	bindToggle(el);
	});
	}

	function bindToggleLink(el, prefix) {
	$(el).click(function() {
	var href = $(el).attr('href');
	var i = href.indexOf('#'+prefix);
	if (i < 0) {
	return;
	}
	var id = '#' + prefix + href.slice(i+1+prefix.length);
	if ($(id).is('.toggle')) {
	$(id).find('.toggleButton').first().click();
	}
	});
	}
	function bindToggleLinks(selector, prefix) {
	$(selector).each(function(i, el) {
	bindToggleLink(el, prefix);
	});
	}

	function setupDropdownPlayground() {
	if (!$('#page').is('.wide')) {
	return; // don't show on front page
	}
	var button = $('#playgroundButton');
	var div = $('#playground');
	var setup = false;
	button.toggle(function() {
	button.addClass('active');
	div.show();
	if (setup) {
	return;
	}
	setup = true;
	playground({
	'codeEl': $('.code', div),
	'outputEl': $('.output', div),
	'runEl': $('.run', div),
	'fmtEl': $('.fmt', div),
	'shareEl': $('.share', div),
	'shareRedirect': '//play.golang.org/p/'
	});
	},
	function() {
	button.removeClass('active');
	div.hide();
	});
	button.show();
	$('#menu').css('min-width', '+=60');
	}

	function setupInlinePlayground() {
	'use strict';
	// Set up playground when each element is toggled.
	$('div.play').each(function (i, el) {
	// Set up playground for this example.
	var setup = function() {
	var code = $('.code', el);
	playground({
	'codeEl': code,
	'outputEl': $('.output', el),
	'runEl': $('.run', el),
	'fmtEl': $('.fmt', el),
	'shareEl': $('.share', el),
	'shareRedirect': '//play.golang.org/p/'
	});

	// Make the code textarea resize to fit content.
	var resize = function() {
	code.height(0);
	var h = code[0].scrollHeight;
	code.height(h+20); // minimize bouncing.
	code.closest('.input').height(h);
	};
	code.on('keydown', resize);
	code.on('keyup', resize);
	code.keyup(); // resize now.
	};

	// If example already visible, set up playground now.
	if ($(el).is(':visible')) {
	setup();
	return;
	}

	// Otherwise, set up playground when example is expanded.
	var built = false;
	$(el).closest('.toggle').click(function() {
	// Only set up once.
	if (!built) {
	setup();
	built = true;
	}
	});
	});
	}

	// fixFocus tries to put focus to div#page so that keyboard navigation works.
	function fixFocus() {
	var page = $('div#page');
	var topbar = $('div#topbar');
	page.css('outline', 0); // disable outline when focused
	page.attr('tabindex', -1); // and set tabindex so that it is focusable
	$(window).resize(function (evt) {
	// only focus page when the topbar is at fixed position (that is, it's in
	// front of page, and keyboard event will go to the former by default.)
	// by focusing page, keyboard event will go to page so that up/down arrow,
	// space, etc. will work as expected.
	if (topbar.css('position') == "fixed")
	page.focus();
	}).resize();
	}

	function toggleHash() {
	var id = window.location.hash.substring(1);
	// Open all of the toggles for a particular hash.
	var els = $(
	document.getElementById(id),
	$('a[name]').filter(function() {
	return $(this).attr('name') == id;
	})
	);

	while (els.length) {
	for (var i = 0; i < els.length; i++) {
	var el = $(els[i]);
	if (el.is('.toggle')) {
	el.find('.toggleButton').first().click();
	}
	}
	els = el.parent();
	}
	}

	function personalizeInstallInstructions() {
	var prefix = '?download=';
	var s = window.location.search;
	if (s.indexOf(prefix) != 0) {
	// No 'download' query string; detect "test" instructions from User Agent.
	if (navigator.platform.indexOf('Win') != -1) {
	$('.testUnix').hide();
	$('.testWindows').show();
	} else {
	$('.testUnix').show();
	$('.testWindows').hide();
	}
	return;
	}

	var filename = s.substr(prefix.length);
	var filenameRE = /^go1\.\d+(\.\d+)?([a-z0-9]+)?\.([a-z0-9]+)(-[a-z0-9]+)?(-osx10\.[68])?\.([a-z.]+)$/;
	$('.downloadFilename').text(filename);
	$('.hideFromDownload').hide();
	var m = filenameRE.exec(filename);
	if (!m) {
	// Can't interpret file name; bail.
	return;
	}

	var os = m[3];
	var ext = m[6];
	if (ext != 'tar.gz') {
	$('#tarballInstructions').hide();
	}
	if (os != 'darwin' \|\| ext != 'pkg') {
	$('#darwinPackageInstructions').hide();
	}
	if (os != 'windows') {
	$('#windowsInstructions').hide();
	$('.testUnix').show();
	$('.testWindows').hide();
	} else {
	if (ext != 'msi') {
	$('#windowsInstallerInstructions').hide();
	}
	if (ext != 'zip') {
	$('#windowsZipInstructions').hide();
	}
	$('.testUnix').hide();
	$('.testWindows').show();
	}

	var download = "https://dl.google.com/go/" + filename;

	var message = $('<p class="downloading">'+
	'Your download should begin shortly. '+
	'If it does not, click <a>this link</a>.</p>');
	message.find('a').attr('href', download);
	message.insertAfter('#nav');

	window.location = download;
	}

	function updateVersionTags() {
	var v = window.goVersion;
	if (/^go[0-9.]+$/.test(v)) {
	$(".versionTag").empty().text(v);
	$(".whereTag").hide();
	}
	}

	function addPermalinks() {
	function addPermalink(source, parent) {
	var id = source.attr("id");
	if (id == "" \|\| id.indexOf("tmp_") === 0) {
	// Auto-generated permalink.
	return;
	}
	if (parent.find("> .permalink").length) {
	// Already attached.
	return;
	}
	parent.append(" ").append($("<a class='permalink'>¶</a>").attr("href", "#" + id));
	}

	$("#page .container").find("h2[id], h3[id]").each(function() {
	var el = $(this);
	addPermalink(el, el);
	});

	$("#page .container").find("dl[id]").each(function() {
	var el = $(this);
	// Add the anchor to the "dt" element.
	addPermalink(el, el.find("> dt").first());
	});
	}

	$(document).ready(function() {
	generateTOC();
	addPermalinks();
	bindToggles(".toggle");
	bindToggles(".toggleVisible");
	bindToggleLinks(".exampleLink", "example_");
	bindToggleLinks(".overviewLink", "");
	bindToggleLinks(".examplesLink", "");
	bindToggleLinks(".indexLink", "");
	setupDropdownPlayground();
	setupInlinePlayground();
	fixFocus();
	setupTypeInfo();
	setupCallgraphs();
	toggleHash();
	personalizeInstallInstructions();
	updateVersionTags();

	// godoc.html defines window.initFuncs in the <head> tag, and root.html and
	// codewalk.js push their on-page-ready functions to the list.
	// We execute those functions here, to avoid loading jQuery until the page
	// content is loaded.
	for (var i = 0; i < window.initFuncs.length; i++) window.initFuncs[i]();
	});

	// -- analysis ---------------------------------------------------------

	// escapeHTML returns HTML for s, with metacharacters quoted.
	// It is safe for use in both elements and attributes
	// (unlike the "set innerText, read innerHTML" trick).
	function escapeHTML(s) {
	return s.replace(/&/g, '&').
	replace(/\"/g, '"').
	replace(/\'/g, ''').
	replace(/</g, '<').
	replace(/>/g, '>');
	}

	// makeAnchor returns HTML for an <a> element, given an anchorJSON object.
	function makeAnchor(json) {
	var html = escapeHTML(json.Text);
	if (json.Href != "") {
	html = "<a href='" + escapeHTML(json.Href) + "'>" + html + "</a>";
	}
	return html;
	}

	function showLowFrame(html) {
	var lowframe = document.getElementById('lowframe');
	lowframe.style.height = "200px";
	lowframe.innerHTML = "<p style='text-align: left;'>" + html + "</p>\n" +
	"<div onclick='hideLowFrame()' style='position: absolute; top: 0; right: 0; cursor: pointer;'>✘</div>"
	};

	document.hideLowFrame = function() {
	var lowframe = document.getElementById('lowframe');
	lowframe.style.height = "0px";
	}

	// onClickCallers is the onclick action for the 'func' tokens of a
	// function declaration.
	document.onClickCallers = function(index) {
	var data = document.ANALYSIS_DATA[index]
	if (data.Callers.length == 1 && data.Callers[0].Sites.length == 1) {
	document.location = data.Callers[0].Sites[0].Href; // jump to sole caller
	return;
	}

	var html = "Callers of <code>" + escapeHTML(data.Callee) + "</code>:<br/>\n";
	for (var i = 0; i < data.Callers.length; i++) {
	var caller = data.Callers[i];
	html += "<code>" + escapeHTML(caller.Func) + "</code>";
	var sites = caller.Sites;
	if (sites != null && sites.length > 0) {
	html += " at line ";
	for (var j = 0; j < sites.length; j++) {
	if (j > 0) {
	html += ", ";
	}
	html += "<code>" + makeAnchor(sites[j]) + "</code>";
	}
	}
	html += "<br/>\n";
	}
	showLowFrame(html);
	};

	// onClickCallees is the onclick action for the '(' token of a function call.
	document.onClickCallees = function(index) {
	var data = document.ANALYSIS_DATA[index]
	if (data.Callees.length == 1) {
	document.location = data.Callees[0].Href; // jump to sole callee
	return;
	}

	var html = "Callees of this " + escapeHTML(data.Descr) + ":<br/>\n";
	for (var i = 0; i < data.Callees.length; i++) {
	html += "<code>" + makeAnchor(data.Callees[i]) + "</code><br/>\n";
	}
	showLowFrame(html);
	};

	// onClickTypeInfo is the onclick action for identifiers declaring a named type.
	document.onClickTypeInfo = function(index) {
	var data = document.ANALYSIS_DATA[index];
	var html = "Type <code>" + data.Name + "</code>: " +
	"      <small>(size=" + data.Size + ", align=" + data.Align + ")</small><br/>\n";
	html += implementsHTML(data);
	html += methodsetHTML(data);
	showLowFrame(html);
	};

	// implementsHTML returns HTML for the implements relation of the
	// specified TypeInfoJSON value.
	function implementsHTML(info) {
	var html = "";
	if (info.ImplGroups != null) {
	for (var i = 0; i < info.ImplGroups.length; i++) {
	var group = info.ImplGroups[i];
	var x = "<code>" + escapeHTML(group.Descr) + "</code> ";
	for (var j = 0; j < group.Facts.length; j++) {
	var fact = group.Facts[j];
	var y = "<code>" + makeAnchor(fact.Other) + "</code>";
	if (fact.ByKind != null) {
	html += escapeHTML(fact.ByKind) + " type " + y + " implements " + x;
	} else {
	html += x + " implements " + y;
	}
	html += "<br/>\n";
	}
	}
	}
	return html;
	}


	// methodsetHTML returns HTML for the methodset of the specified
	// TypeInfoJSON value.
	function methodsetHTML(info) {
	var html = "";
	if (info.Methods != null) {
	for (var i = 0; i < info.Methods.length; i++) {
	html += "<code>" + makeAnchor(info.Methods[i]) + "</code><br/>\n";
	}
	}
	return html;
	}

	// onClickComm is the onclick action for channel "make" and "<-"
	// send/receive tokens.
	document.onClickComm = function(index) {
	var ops = document.ANALYSIS_DATA[index].Ops
	if (ops.length == 1) {
	document.location = ops[0].Op.Href; // jump to sole element
	return;
	}

	var html = "Operations on this channel:<br/>\n";
	for (var i = 0; i < ops.length; i++) {
	html += makeAnchor(ops[i].Op) + " by <code>" + escapeHTML(ops[i].Fn) + "</code><br/>\n";
	}
	if (ops.length == 0) {
	html += "(none)<br/>\n";
	}
	showLowFrame(html);
	};

	$(window).load(function() {
	// Scroll window so that first selection is visible.
	// (This means we don't need to emit id='L%d' spans for each line.)
	// TODO(adonovan): ideally, scroll it so that it's under the pointer,
	// but I don't know how to get the pointer y coordinate.
	var elts = document.getElementsByClassName("selection");
	if (elts.length > 0) {
	elts[0].scrollIntoView()
	}
	});

	// setupTypeInfo populates the "Implements" and "Method set" toggle for
	// each type in the package doc.
	function setupTypeInfo() {
	for (var i in document.ANALYSIS_DATA) {
	var data = document.ANALYSIS_DATA[i];

	var el = document.getElementById("implements-" + i);
	if (el != null) {
	// el != null => data is TypeInfoJSON.
	if (data.ImplGroups != null) {
	el.innerHTML = implementsHTML(data);
	el.parentNode.parentNode.style.display = "block";
	}
	}

	var el = document.getElementById("methodset-" + i);
	if (el != null) {
	// el != null => data is TypeInfoJSON.
	if (data.Methods != null) {
	el.innerHTML = methodsetHTML(data);
	el.parentNode.parentNode.style.display = "block";
	}
	}
	}
	}

	function setupCallgraphs() {
	if (document.CALLGRAPH == null) {
	return
	}
	document.getElementById("pkg-callgraph").style.display = "block";

	var treeviews = document.getElementsByClassName("treeview");
	for (var i = 0; i < treeviews.length; i++) {
	var tree = treeviews[i];
	if (tree.id == null \|\| tree.id.indexOf("callgraph-") != 0) {
	continue;
	}
	var id = tree.id.substring("callgraph-".length);
	$(tree).treeview({collapsed: true, animated: "fast"});
	document.cgAddChildren(tree, tree, [id]);
	tree.parentNode.parentNode.style.display = "block";
	}
	}

	document.cgAddChildren = function(tree, ul, indices) {
	if (indices != null) {
	for (var i = 0; i < indices.length; i++) {
	var li = cgAddChild(tree, ul, document.CALLGRAPH[indices[i]]);
	if (i == indices.length - 1) {
	$(li).addClass("last");
	}
	}
	}
	$(tree).treeview({animated: "fast", add: ul});
	}

	// cgAddChild adds an <li> element for document.CALLGRAPH node cgn to
	// the parent <ul> element ul. tree is the tree's root <ul> element.
	function cgAddChild(tree, ul, cgn) {
	var li = document.createElement("li");
	ul.appendChild(li);
	li.className = "closed";

	var code = document.createElement("code");

	if (cgn.Callees != null) {
	$(li).addClass("expandable");

	// Event handlers and innerHTML updates don't play nicely together,
	// hence all this explicit DOM manipulation.
	var hitarea = document.createElement("div");
	hitarea.className = "hitarea expandable-hitarea";
	li.appendChild(hitarea);

	li.appendChild(code);

	var childUL = document.createElement("ul");
	li.appendChild(childUL);
	childUL.setAttribute('style', "display: none;");

	var onClick = function() {
	document.cgAddChildren(tree, childUL, cgn.Callees);
	hitarea.removeEventListener('click', onClick)
	};
	hitarea.addEventListener('click', onClick);

	} else {
	li.appendChild(code);
	}
	code.innerHTML += " " + makeAnchor(cgn.Func);
	return li
	}

	})();