adamc@1036: // Detect browser quirks that we should be aware of.
adamc@1036: 
adamc@1036: function needsDynPrefix() {
adamc@1260:     var span = document.createElement("span");
adamc@1260:     span.innerHTML = "<script>alert('test');</script>";
adamc@1260:     var scripts = span.getElementsByTagName("script");
adamc@1260:     return scripts.length == 0;
adamc@1036: }
adamc@1036: 
adamc@1036: var dynPrefix = needsDynPrefix() ? "<span style=\"display:none\">A</span>" : "";
adamc@1036: 
adamc@970: // Function versions of operators
adamc@970: 
adamc@970: function not(x) { return !x; }
adamc@970: function neg(x) { return -x; }
adamc@970: 
adamc@970: function eq(x, y) { return x == y; }
adamc@970: function plus(x, y) { return x + y; }
adamc@970: function minus(x, y) { return x - y; }
adamc@970: function times(x, y) { return x * y; }
adamc@970: function div(x, y) { return x / y; }
adam@1360: function divInt(x, y) { var n = x / y; return n < 0 ? Math.ceil(n) : Math.floor(n); }
adamc@970: function mod(x, y) { return x % y; }
adam@1360: function modInt(x, y) { var n = x % y; return n < 0 ? Math.ceil(n) : Math.floor(n); }
adamc@970: function lt(x, y) { return x < y; }
adamc@970: function le(x, y) { return x <= y; }
adamc@970: 
adamc@1061: // Characters
adamc@1061: 
adamc@1061: function isLower(c) { return c >= 'a' && c <= 'z'; }
adamc@1061: function isUpper(c) { return c >= 'A' && c <= 'Z'; }
adamc@1061: function isAlpha(c) { return isLower(c) || isUpper(c); }
adamc@1061: function isDigit(c) { return c >= '0' && c <= '9'; }
adamc@1061: function isAlnum(c) { return isAlpha(c) || isDigit(c); }
adamc@1061: function isBlank(c) { return c == ' ' || c == '\t'; }
adamc@1061: function isSpace(c) { return isBlank(c) || c == '\r' || c == '\n'; }
adamc@1061: function isXdigit(c) { return isDigit(c) || (c >= 'a' && c <= 'f') || (c >= 'A' && c <= 'F'); }
adamc@1177: function toLower(c) { return c.toLowerCase(); }
adamc@1177: function toUpper(c) { return c.toUpperCase(); }
adamc@1061: 
adamc@1061: 
adamc@692: // Lists
adamc@692: 
adamc@580: function cons(v, ls) {
adamc@1260:     return { next : ls, data : v };
adamc@690: }
adamc@969: function rev(ls) {
adamc@1260:     var acc = null;
adamc@1260:     for (; ls; ls = ls.next)
adamc@1260:         acc = cons(ls.data, acc);
adamc@1260:     return acc;
adamc@969: }
adamc@690: function concat(ls1, ls2) {
adamc@1260:     var acc = ls2;
adamc@1260:     ls1 = rev(ls1);
adamc@1260:     for (; ls1; ls1 = ls1.next)
adamc@1260:         acc = cons(ls1.data, acc);
adamc@1260:     return acc;
adamc@690: }
adamc@690: function member(x, ls) {
adamc@1260:     for (; ls; ls = ls.next)
adamc@1260:         if (ls.data == x)
adamc@1260:             return true;
adamc@1260:     return false;
adamc@690: }
adamc@690: function remove(x, ls) {
adamc@1260:     var acc = null;
adamc@969: 
adamc@1260:     for (; ls; ls = ls.next)
adamc@1260:         if (ls.data == x)
adamc@1260:             return concat(acc, ls.next);
adamc@1260:         else
adamc@1260:             acc = cons(ls.data, acc);
adamc@969: 
adamc@1260:     return ls;
adamc@690: }
adamc@690: function union(ls1, ls2) {
adamc@1260:     var acc = ls2;
adamc@969: 
adamc@1260:     for (; ls1; ls1 = ls1.next)
adamc@1260:         if (!member(ls1.data, ls2))
adamc@1260:             acc = cons(ls1.data, acc);
adamc@969: 
adamc@1260:     return acc;
adamc@580: }
adamc@703: function length(ls) {
adamc@1260:     var acc = 0;
adamc@969: 
adamc@1260:     for (; ls; ls = ls.next)
adamc@1260:         ++acc;
adamc@969: 
adamc@1260:     return acc;
adamc@703: }
adamc@670: 
adamc@690: 
adam@1487: // Time
adam@1487: 
adam@1487: function showTime(tm) {
adam@1487:     var newDate = new Date();
adam@1487:     newDate.setTime(tm / 1000);
adam@1487:     return newDate.toUTCString();
adam@1487: }
adam@1487: 
adam@1487: function now() {
adam@1487:     return (new Date()).getTime() * 1000;
adam@1487: }
adam@1487: 
adam@1514: function diffInSeconds(tm1, tm2) {
adam@1514:     return Math.round((tm2 - tm1) / 1000000);
adam@1514: }
adam@1514: 
adam@1514: function toSeconds(tm) {
adam@1514:     return Math.round(tm / 1000000);
adam@1514: }
adam@1514: 
adam@1518: function addSeconds(tm, n) {
adam@1518:     return tm + n * 1000000;
adam@1518: }
adam@1518: 
adam@1487: 
adamc@729: // Error handling
adamc@729: 
adamc@729: function whine(msg) {
adamc@1260:     alert(msg);
adamc@1260:     throw msg;
adamc@729: }
adamc@729: 
adamc@810: function pf(loc) {
adamc@1260:     throw ("Pattern match failure (" + loc + ")");
adamc@729: }
adamc@729: 
adam@1553: var lameDuck = false;
adam@1553: 
adamc@798: function runHandlers(kind, ls, arg) {
adam@1553:     if (!lameDuck) {
adam@1553:         if (ls == null)
adam@1553:             alert(kind + ": " + arg);
adam@1553:         for (; ls; ls = ls.next)
adam@1553:             try {
adam@1553:                 exec({c:"a", f:{c:"a", f:ls.data, x:{c:"c", v:arg}}, x:{c:"c", v:null}});
adam@1553:             } catch (v) { }
adam@1553:     }
adamc@729: }
adamc@729: 
adamc@729: var errorHandlers = null;
adamc@729: 
adamc@729: function onError(f) {
adamc@1260:     errorHandlers = cons(f, errorHandlers);
adamc@729: }
adamc@729: 
adamc@729: function er(s) {
adamc@1260:     runHandlers("Error", errorHandlers, s);
adamc@1260:     throw {uw_error: s};
adamc@729: }
adamc@729: 
adamc@729: var failHandlers = null;
adamc@729: 
adamc@729: function onFail(f) {
adamc@1260:     failHandlers = cons(f, failHandlers);
adamc@729: }
adamc@729: 
adamc@729: function doExn(v) {
adamc@1260:     if (v == null || v.uw_error == null) {
adamc@1260:         var s = (v == null ? "null" : v.message ? v.message : v.toString());
adamc@1260:         if (v != null && v.fileName && v.lineNumber)
adamc@1260:             s += " (" + v.fileName + ":" + v.lineNumber + ")";
adamc@1260:         runHandlers("Fail", failHandlers, s);
adamc@1260:     }
adamc@729: }
adamc@729: 
adamc@729: var disconnectHandlers = null;
adamc@729: 
adamc@976: function flift(f) {
kkallio@1484:     return {c: "c", v:{env:cons(f,null), body:{c:"v", n:1}}};
adamc@976: }
adamc@976: 
adamc@729: function onDisconnect(f) {
adamc@1260:     disconnectHandlers = cons(flift(f), disconnectHandlers);
adamc@729: }
adamc@729: 
adamc@729: function discon() {
adamc@1260:     runHandlers("Disconnect", disconnectHandlers, null);
adamc@729: }
adamc@729: 
adamc@729: var connectHandlers = null;
adamc@729: 
adamc@729: function onConnectFail(f) {
adamc@1260:     connectHandlers = cons(flift(f), connectHandlers);
adamc@729: }
adamc@729: 
adamc@729: function conn() {
adamc@1260:     runHandlers("Connect", connectHandlers, null);
adamc@729: }
adamc@729: 
adamc@729: var serverHandlers = null;
adamc@729: 
adamc@729: function onServerError(f) {
adamc@1260:     serverHandlers = cons(f, serverHandlers);
adamc@729: }
adamc@729: 
adamc@729: function servErr(s) {
adamc@1260:     window.setTimeout(function () { runHandlers("Server", serverHandlers, s); }, 0);
adamc@729: }
adamc@729: 
adam@1555: // Key events
adam@1555: 
adam@1555: var uw_event = null;
adam@1555: 
adam@1555: function kc() {
adam@1555:     return window.event ? event.keyCode : (uw_event ? uw_event.which : 0);
adam@1555: }
adam@1555: 
adam@1555: // Document events
adam@1555: 
adam@1555: function uw_handler(name, f) {
adam@1555:     var old = document[name];
adam@1555:     if (old == undefined)
adam@1559:         document[name] = function(event) { uw_event = event; execF(f); };
adam@1555:     else
adam@1559:         document[name] = function(event) { uw_event = event; old(); execF(f); };
adam@1555: }
adam@1555: 
adam@1555: function uw_onClick(f) {
adam@1555:     uw_handler("onclick", f);
adam@1555: }
adam@1555: 
adam@1555: function uw_onDblclick(f) {
adam@1555:     uw_handler("ondblclick", f);
adam@1555: }
adam@1555: 
adam@1555: function uw_onMousedown(f) {
adam@1555:     uw_handler("onmousedown", f);
adam@1555: }
adam@1555: 
adam@1555: function uw_onMouseup(f) {
adam@1555:     uw_handler("onmouseup", f);
adam@1555: }
adam@1555: 
adam@1555: function uw_keyHandler(name, f) {
adam@1555:     var old = document[name];
adam@1555:     if (old == undefined)
adam@1559:         document[name] = function(event) { uw_event = event; execF(execF(f, kc())); };
adam@1555:     else
adam@1559:         document[name] = function(event) { uw_event = event; old(); execF(execF(f, kc())); };
adam@1555: }
adam@1555: 
adam@1555: function uw_onKeydown(f) {
adam@1555:     uw_keyHandler("onkeydown", f);
adam@1555: }
adam@1555: 
adam@1555: function uw_onKeypress(f) {
adam@1555:     uw_keyHandler("onkeypress", f);
adam@1555: }
adam@1555: 
adam@1555: function uw_onKeyup(f) {
adam@1555:     uw_keyHandler("onkeyup", f);
adam@1555: }
adam@1555: 
adam@1559: // Cancelling of further event processing
adam@1559: 
adam@1559: function uw_preventDefault() {
adam@1559:     var e = window.event ? window.event : uw_event;
adam@1559:     e.returnValue = false;
adam@1559:     if (e.preventDefault) e.preventDefault();
adam@1559: }
adam@1559: 
adam@1559: function uw_stopPropagation() {
adam@1559:     var e = window.event ? window.event : uw_event;
adam@1559:     e.cancelBubble = true;
adam@1559:     if (e.stopPropagation) e.stopPropagation();
adam@1559: }
adamc@729: 
adamc@692: // Embedding closures in XML strings
adamc@692: 
adamc@693: function cs(f) {
adamc@1260:     return {closure: f};
adamc@693: }
adamc@693: 
adamc@693: function isWeird(v) {
adamc@1260:     return v.closure != null || v.cat1 != null;
adamc@693: }
adamc@693: 
adamc@692: function cat(s1, s2) {
adamc@1260:     if (isWeird(s1) || isWeird(s2))
adamc@1260:         return {cat1: s1, cat2: s2};
adamc@1260:     else
adamc@1260:         return s1 + s2;
adamc@692: }
adamc@692: 
adamc@692: var closures = [];
adamc@703: var freeClosures = null;
adamc@692: 
adamc@692: function newClosure(f) {
adamc@1260:     var n;
adamc@1260:     if (freeClosures == null) {
adamc@1260:         n = closures.length;
adamc@1260:     } else {
adamc@1260:         n = freeClosures.data;
adamc@1260:         freeClosures = freeClosures.next;
adamc@1260:     }
adamc@1260:     closures[n] = f;
adamc@1260:     return n;
adamc@692: }
adamc@692: 
adamc@703: function freeClosure(n) {
adamc@1260:     closures[n] = null;
adamc@1260:     freeClosures = cons(n, freeClosures);
adamc@703: }
adamc@703: 
adamc@692: function cr(n) {
adamc@1260:     return closures[n];
adamc@692: }
adamc@692: 
adamc@703: function flatten(cls, tr) {
adamc@1260:     if (tr.cat1 != null)
adamc@1260:         return flatten(cls, tr.cat1) + flatten(cls, tr.cat2);
adamc@1260:     else if (tr.closure != null) {
adamc@1260:         var cl = newClosure(tr.closure);
adamc@1260:         cls.v = cons(cl, cls.v);
adamc@1260:         return "cr(" + cl + ")";
adamc@1260:     } else
adamc@1260:         return tr;
adamc@692: }
adamc@692: 
adamc@728: function flattenLocal(s) {
adamc@1260:     var cls = {v : null};
adamc@1260:     var r = flatten(cls, s);
adamc@1260:     for (cl = cls.v; cl != null; cl = cl.next)
adamc@1260:         freeClosure(cl.data);
adamc@1260:     return r;
adamc@728: }
adamc@728: 
adamc@692: 
adamc@692: 
adamc@692: // Dynamic tree management
adamc@692: 
adamc@690: function populate(node) {
adamc@1260:     var s = node.signal;
adamc@1260:     var oldSources = node.sources;
adamc@1260:     try {
adamc@1260:         var sr = execF(s, null);
adamc@1260:         var newSources = sr._sources;
adamc@690: 
adamc@1260:         for (var sp = oldSources; sp; sp = sp.next)
adamc@1260:             if (!member(sp.data, newSources))
adamc@1260:                 sp.data.dyns = remove(node, sp.data.dyns);
adamc@690: 
adamc@1260:         for (var sp = newSources; sp; sp = sp.next)
adamc@1260:             if (!member(sp.data, oldSources))
adamc@1260:                 sp.data.dyns = cons(node, sp.data.dyns);
adamc@690: 
adamc@1260:         node.sources = newSources;
adamc@1260:         node.recreate(sr._data);
adamc@1260:     } catch (v) {
adamc@1260:         doExn(v);
adamc@1260:     }
adamc@579: }
adamc@574: 
adamc@580: function sc(v) {
adamc@1260:     return {data : v, dyns : null};
adamc@580: }
adamc@580: function sv(s, v) {
adam@1491:     if (s.data != v) {
adam@1491:         s.data = v;
adamc@967: 
adam@1491:         for (var ls = s.dyns; ls; ls = ls.next)
adam@1491:             if (!ls.dead)
adam@1491:                 populate(ls.data);
adam@1491:     }
adamc@580: }
adamc@601: function sg(s) {
adamc@1260:     return s.data;
adamc@601: }
adamc@579: 
adamc@580: function ss(s) {
adamc@1260:     return {env:cons(s, null), body:{c:"r", l:
adamc@1260:             cons({n:"sources", v:{c:"c", v:cons(s, null)}},
adamc@1260:                  cons({n:"data", v:{c:"f", f:sg, a:cons({c:"v", n:1}, null)}}, null))}};
adamc@580: }
adamc@580: function sr(v) {
adamc@1260:     return {env:null, body:{c:"c", v:{_sources : null, _data : v}}};
adamc@580: }
adamc@580: function sb(x,y) {
adamc@1260:     return {env:cons(y,cons(x,null)),
adamc@1260:             body:{c:"=",
adamc@1260:                 e1:{c:"a", f:{c:"v", n:2}, x:{c:"c", v:null}},
adamc@1260:                 e2:{c:"=",
adamc@1260:                     e1:{c:"a",
adamc@1260:                         f:{c:"a", f:{c:"v", n:2}, x:{c:".", r:{c:"v", n:0}, f:"data"}},
adamc@1260:                         x:{c:"c", v:null}},
adamc@1260:                     e2:{c:"r", l:cons(
adamc@1260:                                       {n:"sources", v:{c:"f", f:union, a:cons({c:".", r:{c:"v", n:1}, f:"sources"},
adamc@1260:                                                                               cons({c:".", r:{c:"v", n:0}, f:"sources"}, null))}},
adamc@1260:                                       cons({n:"data", v:{c:".", r:{c:"v", n:0}, f:"data"}}, null))}}}};
adamc@580: }
adamc@841: function scur(s) {
adamc@1260:     return execF(s, null)._data;
adamc@841: }
adamc@571: 
adamc@604: function lastParent() {
adamc@1260:     var pos = document.body;
adamc@604: 
adamc@1260:     while (pos.lastChild && pos.lastChild.nodeType == 1)
adamc@1260:         pos = pos.lastChild;
adamc@600: 
adamc@1260:     pos = pos.parentNode;
adamc@1039: 
adamc@1260:     return pos;
adamc@600: }
adamc@600: 
adamc@898: function parent() {
adamc@1260:     return thisScript ? thisScript.parentNode : lastParent();
adamc@898: }
adamc@898: 
adamc@604: function addNode(node) {
adamc@1260:     if (thisScript)
adamc@1260:         thisScript.parentNode.replaceChild(node, thisScript);
adamc@1260:     else
adamc@1260:         lastParent().appendChild(node);
adamc@603: }
adamc@603: 
adamc@690: var thisScript = null;
adamc@690: 
adamc@604: function runScripts(node) {
adamc@1260:     if (node.getElementsByTagName) {
adamc@1260:         var savedScript = thisScript;
adamc@603: 
adamc@1260:         var scripts = node.getElementsByTagName("script"), scriptsCopy = [];
adamc@1260:         var len = scripts.length;
adamc@1260:         for (var i = 0; i < len; ++i)
adamc@1260:             scriptsCopy[i] = scripts[i];
adamc@1260:         for (var i = 0; i < len; ++i) {
adamc@1260:             thisScript = scriptsCopy[i];
adamc@1039: 
adamc@1260:             try {
adamc@1260:                 eval(thisScript.text);
adamc@1260:             } catch (v) {
adamc@1260:                 doExn(v);
adamc@1260:             }
adamc@1260:             if (thisScript.parentNode)
adamc@1260:                 thisScript.parentNode.removeChild(thisScript);
adamc@1260:         }
adamc@1260: 
adamc@1260:         thisScript = savedScript;
adamc@729:     }
adamc@603: }
adamc@603: 
adamc@603: 
adamc@692: // Dynamic tree entry points
adamc@692: 
adamc@967: function killScript(scr) {
adamc@1260:     scr.dead = true;
adamc@1260:     for (var ls = scr.sources; ls; ls = ls.next)
adamc@1260:         ls.data.dyns = remove(scr, ls.data.dyns);
adamc@1260:     for (var ls = scr.closures; ls; ls = ls.next)
adamc@1260:         freeClosure(ls.data);
adamc@967: }
adamc@967: 
adam@1538: // Sometimes we wind up with tables that contain <script>s outside the single <tbody>.
adam@1538: // To avoid dealing with that case, we normalize by moving <script>s into <tbody>.
adam@1538: function normalizeTable(table) {
adam@1538:     var orig = table;
adam@1538: 
adam@1538:     var script, next;
adam@1538: 
adam@1538:     while (table.tagName != "TABLE")
adam@1538:         table = table.parentNode;
adam@1538: 
adam@1538:     for (var tbody = table.firstChild; tbody; tbody = tbody.nextSibling) {
adam@1538:         if (tbody.tagName == "TBODY") {
adam@1538:             for (script = table.firstChild; script && script != tbody; script = next) {
adam@1538:                 next = script.nextSibling;
adam@1538: 
adam@1538:                 tbody.insertBefore(script, tbody.firstChild);
adam@1538:             }
adam@1538: 
adam@1538:             return;
adam@1538:         }
adam@1538:     }
adam@1538: 
adam@1538:     var tbody = document.createElement("tbody");
adam@1538:     for (script = table.firstChild; script; script = next) {
adam@1538:         next = script.nextSibling;
adam@1538:         
adam@1538:         tbody.insertBefore(script, tbody.firstChild);
adam@1538:     }
adam@1538:     table.appendChild(tbody);
adam@1538: }
adam@1538: 
adamc@901: function dyn(pnode, s) {
adamc@1260:     var x = document.createElement("script");
adamc@1260:     x.dead = false;
adamc@1260:     x.signal = s;
adamc@1260:     x.sources = null;
adamc@1260:     x.closures = null;
adamc@899: 
adamc@1260:     var firstChild = null;
adamc@899: 
adamc@1260:     x.recreate = function(v) {
adamc@1260:         for (var ls = x.closures; ls; ls = ls.next)
adamc@1260:             freeClosure(ls.data);
adamc@945: 
adamc@946:         var next;
adamc@1260:         for (var child = firstChild; child && child != x; child = next) {
adamc@1260:             next = child.nextSibling;
adamc@1260: 
adamc@1260:             killScript(child);
adamc@1260:             if (child.getElementsByTagName) {
adamc@1260:                 var arr = child.getElementsByTagName("script");
adamc@1260:                 for (var i = 0; i < arr.length; ++i)
adamc@1260:                     killScript(arr[i]);
adamc@1260:             }
adamc@1260: 
adamc@1260:             if (child.parentNode)
adamc@1260:                 child.parentNode.removeChild(child);
adamc@946:         }
adamc@903: 
adamc@1260:         var cls = {v : null};
adamc@1260:         var html = flatten(cls, v);
adamc@1260:         if (pnode != "table" && pnode != "tr")
adamc@1260:             html = dynPrefix + html;
adamc@1260:         x.closures = cls.v;
adamc@946: 
adamc@1260:         if (pnode == "table") {
adam@1538:             normalizeTable(x.parentNode);
adam@1538: 
adamc@1260:             var dummy = document.createElement("body");
adamc@1260:             dummy.innerHTML = "<table>" + html + "</table>";
adamc@1260:             runScripts(dummy);
adamc@1260:             var table = x.parentNode;
adamc@1260: 
adamc@1260:             if (table) {
adamc@1260:                 firstChild = null;
adamc@1260:                 var tbody;
adamc@1260: 
adamc@1260:                 var arr = dummy.getElementsByTagName("tbody");
adamc@1260: 
adamc@1260:                 var tbody;
adamc@1260:                 if (arr.length > 0 && arr[0].parentNode == dummy.firstChild) {
adamc@1260:                     tbody = arr[0];
adamc@1260:                     var next;
adamc@1260:                     for (var node = dummy.firstChild.firstChild; node; node = next) {
adamc@1260:                         next = node.nextSibling;
adamc@1260: 
adamc@1260:                         if (node.tagName != "TBODY")
adamc@1260:                             tbody.appendChild(node);
adamc@1260:                     }
adamc@1260:                 } else
adamc@1260:                     tbody = dummy.firstChild;
adamc@1260: 
adamc@1260:                 var next;
adamc@1260:                 firstChild = document.createElement("script");
adamc@1260:                 table.insertBefore(firstChild, x);
adamc@1260:                 for (var node = tbody.firstChild; node; node = next) {
adamc@1260:                     next = node.nextSibling;
adamc@1260:                     table.insertBefore(node, x);
adamc@1260:                 }
adamc@1260:             }
adamc@1260:         } else if (pnode == "tr") {
adamc@1260:             var dummy = document.createElement("body");
adamc@1260:             dummy.innerHTML = "<table><tr>" + html + "</tr></table>";
adamc@1260:             runScripts(dummy);
adamc@1260:             var table = x.parentNode;
adamc@1260: 
adamc@1260:             if (table) {
adamc@1260:                 var arr = dummy.getElementsByTagName("tr");
adamc@1260:                 firstChild = null;
adamc@1260:                 var tr;
adamc@1260:                 if (arr.length > 0 && table != null)
adamc@1260:                     tr = arr[0];
adamc@1260:                 else
adamc@1260:                     tr = dummy.firstChild;
adamc@1260: 
adamc@1260:                 var next;
adamc@1260:                 firstChild = document.createElement("script");
adamc@1260:                 table.insertBefore(firstChild, x);
adamc@1260:                 for (var node = tr.firstChild; node; node = next) {
adamc@1260:                     next = node.nextSibling;
adamc@1260:                     table.insertBefore(node, x);
adamc@1260:                 }
adamc@1260:             }
adamc@1260:         } else {
adamc@1260:             firstChild = document.createElement("span");
adamc@1260:             firstChild.innerHTML = html;
adamc@1260:             runScripts(firstChild);
adamc@1260:             if (x.parentNode)
adamc@1260:                 x.parentNode.insertBefore(firstChild, x);
adamc@903:         }
adamc@1260:     };
adamc@899: 
adamc@1260:     addNode(x);
adamc@1260:     populate(x);
adamc@571: }
adamc@582: 
adam@1463: function input(x, s, recreate, type, name) {
adam@1463:     if (name) x.name = name;
adamc@1260:     if (type) x.type = type;
adamc@1260:     x.dead = false;
adamc@1260:     x.signal = ss(s);
adamc@1260:     x.sources = null;
adamc@1260:     x.recreate = recreate(x);
adamc@1260:     addNode(x);
adamc@1260:     populate(x);
adamc@816: 
adamc@1260:     return x;
adamc@816: }
adamc@816: 
adam@1463: function inp(s, name) {
adamc@1260:     var x = input(document.createElement("input"), s,
adam@1463:                   function(x) { return function(v) { if (x.value != v) x.value = v; }; }, null, name);
adamc@1260:     x.value = s.data;
adam@1491:     x.onkeyup = x.oninput = x.onchange = x.onpropertychange = function() { sv(s, x.value) };
adamc@816: 
adamc@1260:     return x;
adamc@816: }
adamc@816: 
adam@1479: function selectValue(x) {
adam@1479:     if (x.options.length == 0)
adam@1479:         return "";
adam@1479:     else
adam@1479:         return x.options[x.selectedIndex].value;
adam@1479: }
adam@1479: 
adam@1479: function setSelectValue(x, v) {
adam@1479:   for (var i = 0; i < x.options.length; ++i) {
adam@1479:       if(x.options[i].value == v) {
adam@1479:           x.selectedIndex = i;
adam@1479:           return;
adam@1479:       }
adam@1479:   }
adam@1479: }
adam@1479: 
adamc@816: function sel(s, content) {
adamc@1260:     var dummy = document.createElement("span");
adamc@1260:     dummy.innerHTML = "<select>" + content + "</select>";
adam@1479:     var x = input(dummy.firstChild, s, function(x) { return function(v) { if (selectValue(x) != v) setSelectValue(x, v); }; });
adam@1479: 
adam@1479:     for (var i = 0; i < x.options.length; ++i) {
adam@1479:         if (x.options[i].value == "")
adam@1479:             x.options[i].value = x.options[i].text;
adam@1479:         else
adam@1479:             x.options[i].value = x.options[i].value.substring(1);
adam@1479:     }
adam@1479: 
adam@1479:     setSelectValue(x, s.data);
adam@1479:     if (selectValue(x) != s.data)
adam@1479:         sv(s, selectValue(x));
adam@1479:     x.onchange = function() { sv(s, selectValue(x)) };
adamc@797: 
adamc@1260:     return x;
adamc@598: }
adamc@598: 
adamc@817: function chk(s) {
adamc@1260:     var x = input(document.createElement("input"), s,
adamc@1260:                   function(x) { return function(v) { if (x.checked != v) x.checked = v; }; }, "checkbox");
adamc@1260:     x.defaultChecked = x.checked = s.data;
adamc@1260:     x.onclick = function() { sv(s, x.checked) };
adamc@817: 
adamc@1260:     return x;
adamc@817: }
adamc@817: 
adamc@1099: function tbx(s) {
adamc@1260:     var x = input(document.createElement("textarea"), s,
adamc@1260:                   function(x) { return function(v) { if (x.innerHTML != v) x.innerHTML = v; }; });
adamc@1260:     x.innerHTML = s.data;
adam@1491:     x.onkeyup = x.oninput = x.onchange = x.onpropertychange = function() { sv(s, x.value) };
adamc@1099: 
adamc@1260:     return x;
adamc@1099: }
adamc@1099: 
adamc@800: function addOnChange(x, f) {
adamc@1260:     var old = x.onchange;
adam@1290:     if (old == null)
adam@1290:         x.onchange = f;
adam@1290:     else
adam@1290:         x.onchange = function() { old(); f(); };
adam@1290: }
adam@1290: 
adam@1290: function addOnKeyUp(x, f) {
adam@1290:     var old = x.onkeyup;
adam@1290:     if (old == null)
adam@1290:         x.onkeyup = f;
adam@1290:     else
adam@1290:         x.onkeyup = function(x) { old(x); f(x); };
adamc@800: }
adamc@800: 
adamc@692: 
adamc@692: // Basic string operations
adamc@692: 
adamc@597: function eh(x) {
adamc@1260:     if (x == null)
adamc@1260:         return "NULL";
adamc@1260:     else
adamc@1260:         return x.split("&").join("&amp;").split("<").join("&lt;").split(">").join("&gt;");
adamc@597: }
adamc@597: 
adamc@582: function ts(x) { return x.toString() }
adamc@586: function bs(b) { return (b ? "True" : "False") }
adamc@586: 
adamc@1057: function id(x) { return x; }
adamc@1038: function sub(s, i) { return s.charAt(i); }
adamc@828: function suf(s, i) { return s.substring(i); }
adamc@828: function slen(s) { return s.length; }
adamc@829: function sidx(s, ch) {
adamc@1260:     var r = s.indexOf(ch);
adamc@1260:     if (r == -1)
adamc@1260:         return null;
adamc@1260:     else
adamc@1260:         return r;
adamc@829: }
adamc@831: function sspn(s, chs) {
adamc@1260:     for (var i = 0; i < s.length; ++i)
adamc@1260:         if (chs.indexOf(s.charAt(i)) != -1)
adamc@1260:             return i;
adamc@831: 
adamc@1260:     return null;
adamc@831: }
adamc@829: function schr(s, ch) {
adamc@1260:     var r = s.indexOf(ch);
adamc@1260:     if (r == -1)
adamc@1260:         return null;
adamc@1260:     else
adamc@1260:         return s.substring(r);
adamc@829: }
adamc@829: function ssub(s, start, len) {
adamc@1260:     return s.substring(start, start+len);
adamc@829: }
adamc@821: 
adamc@649: function pi(s) {
adamc@1260:     var r = parseInt(s);
adamc@1260:     if (r.toString() == s)
adamc@1260:         return r;
adamc@1260:     else
adamc@1260:         er("Can't parse int: " + s);
adamc@649: }
adamc@649: 
adamc@649: function pfl(s) {
adamc@1260:     var r = parseFloat(s);
adamc@1260:     if (r.toString() == s)
adamc@1260:         return r;
adamc@1260:     else
adamc@1260:         er("Can't parse float: " + s);
adamc@649: }
adamc@649: 
adamc@838: function pio(s) {
adamc@1260:     var r = parseInt(s);
adamc@1260:     if (r.toString() == s)
adamc@1260:         return r;
adamc@1260:     else
adamc@1260:         return null;
adamc@838: }
adamc@838: 
adamc@838: function pflo(s) {
adamc@1260:     var r = parseFloat(s);
adamc@1260:     if (r.toString() == s)
adamc@1260:         return r;
adamc@1260:     else
adamc@1260:         return null;
adamc@838: }
adamc@838: 
adamc@692: function uf(s) {
adamc@1260:     if (s.length == 0)
adamc@1260:         return "_";
adamc@1260:     s = s.replace(new RegExp ("\\.", "g"), ".2E");
adamc@1260:     return (s.charAt(0) == '_' ? "_" : "") + encodeURIComponent(s).replace(new RegExp ("%", "g"), ".");
adamc@691: }
adamc@691: 
adamc@692: function uu(s) {
adamc@1260:     if (s.length > 0 && s.charAt(0) == '_') {
adamc@1260:         s = s.substring(1);
adamc@1260:     } else if (s.length >= 3 && (s.charAt(0) == '%' || s.charAt(0) == '.')
adamc@1260:                && s.charAt(1) == '5' && (s.charAt(2) == 'f' || s.charAt(2) == 'F'))
adamc@1260:         s = s.substring(3);
adamc@1260:     s = s.replace(new RegExp ("\\+", "g"), " ");
adamc@1260:     s = s.replace(new RegExp ("\\.", "g"), "%");
adamc@1260:     return decodeURIComponent(s);
adamc@905: }
adamc@905: 
adamc@1108: function atr(s) {
adamc@1260:     return s.replace(new RegExp ("\"", "g"), "&quot;").replace(new RegExp ("&", "g"), "&amp;")
adamc@1260:         }
adamc@1108: 
adamc@912: function ub(b) {
adamc@1260:     return b ? "1" : "0";
adamc@912: }
adamc@912: 
adamc@905: function uul(getToken, getData) {
adamc@1260:     var tok = getToken();
adamc@1260:     if (tok == "Nil") {
adamc@1260:         return null;
adamc@1260:     } else if (tok == "Cons") {
adamc@1260:         var d = getData();
adamc@1260:         var l = uul(getToken, getData);
adamc@1260:         return {_1:d, _2:l};
adamc@1260:     } else
adamc@1260:         whine("Can't unmarshal list (" + tok + ")");
adamc@692: }
adamc@692: 
adamc@961: function strcmp(str1, str2) {
adamc@1260:     return ((str1 == str2) ? 0 : ((str1 > str2) ? 1 : -1));
adamc@961: }
adamc@692: 
adamc@603: 
adamc@692: // Remote calls
adamc@609: 
adamc@703: var client_id = null;
adamc@668: var client_pass = 0;
adamc@668: var url_prefix = "/";
adamc@673: var timeout = 60;
adam@1552: var isPost = false;
adamc@668: 
adamc@668: function getXHR(uri)
adamc@609: {
adamc@609:     try {
adamc@1260:         return new XMLHttpRequest();
adamc@609:     } catch (e) {
adamc@1260:         try {
adamc@1260:             return new ActiveXObject("Msxml2.XMLHTTP");
adamc@1260:         } catch (e) {
adamc@1260:             try {
adamc@1260:                 return new ActiveXObject("Microsoft.XMLHTTP");
adamc@1260:             } catch (e) {
adamc@1260:                 whine("Your browser doesn't seem to support AJAX.");
adamc@1260:             }
adamc@1260:         }
adamc@609:     }
adamc@609: }
adamc@609: 
adamc@736: var sig = null;
adamc@736: 
adamc@1042: var unloading = false, inFlight = null;
adamc@1042: 
adamc@1042: function unload() {
adamc@1260:     unloading = true;
adamc@1042: 
adamc@1260:     for (; inFlight; inFlight = inFlight.next) {
adamc@1260:         inFlight.data.abort();
adamc@1260:     }
adamc@1042: }
adamc@1042: 
adamc@736: function requestUri(xhr, uri, needsSig) {
adamc@1260:     if (unloading)
adamc@1260:         return;
adamc@1042: 
adamc@1260:     xhr.open("POST", uri, true);
adamc@1260:     xhr.setRequestHeader("Content-type", "text/plain");
adam@1549:     try {
adam@1549:         xhr.setRequestHeader("Content-length", "0");
adam@1549:         xhr.setRequestHeader("Connection", "close");
adam@1549:     } catch (e) { }
adamc@668: 
adamc@1260:     if (client_id != null) {
adamc@1260:         xhr.setRequestHeader("UrWeb-Client", client_id.toString());
adamc@1260:         xhr.setRequestHeader("UrWeb-Pass", client_pass.toString());
adamc@1260:     }
adamc@668: 
adamc@1260:     if (needsSig) {
adamc@1260:         if (sig == null)
adamc@1260:             whine("Missing cookie signature!");
adamc@736: 
adamc@1260:         xhr.setRequestHeader("UrWeb-Sig", sig);
adamc@1260:     }
adamc@736: 
adamc@1260:     inFlight = cons(xhr, inFlight);
adamc@1260:     xhr.send(null);
adamc@668: }
adamc@668: 
adamc@1042: function xhrFinished(xhr) {
adamc@1260:     xhr.abort();
adamc@1260:     inFlight = remove(xhr, inFlight);
adamc@1042: }
adamc@1042: 
adamc@1111: function unurlify(parse, s) {
adamc@1260:     return parse(s);
adamc@1111: }
adamc@1111: 
adam@1385: function redirect(s) {
adam@1385:     window.location = s;
adam@1385: }
adam@1385: 
adamc@978: function rc(prefix, uri, parse, k, needsSig) {
adamc@1260:     uri = cat(prefix, uri);
adamc@1260:     uri = flattenLocal(uri);
adamc@1260:     var xhr = getXHR();
adamc@609: 
adamc@1260:     xhr.onreadystatechange = function() {
adamc@1260:         if (xhr.readyState == 4) {
adamc@1260:             var isok = false;
adamc@612: 
adamc@1260:             try {
adamc@1260:                 if (xhr.status == 200)
adamc@1260:                     isok = true;
adamc@1260:             } catch (e) { }
adamc@612: 
adamc@1260:             if (isok) {
adam@1446:                 var lines = xhr.responseText.split("\n");
adam@1446:                 if (lines.length != 2)
adam@1446:                     whine("Bad RPC response lines");
adam@1446: 
adam@1446:                 eval(lines[0]);
adam@1446: 
adamc@1260:                 try {
adam@1446:                     k(parse(lines[1]));
adamc@1260:                 } catch (v) {
adamc@1260:                     doExn(v);
adamc@1260:                 }
adamc@1260:             } else {
adamc@1260:                 conn();
adamc@1260:             }
adamc@1260: 
adamc@1260:             xhrFinished(xhr);
adamc@729:         }
adamc@1260:     };
adamc@1042: 
adamc@1260:     requestUri(xhr, uri, needsSig);
adamc@609: }
adamc@667: 
adamc@667: function path_join(s1, s2) {
adamc@1260:     if (s1.length > 0 && s1.charAt(s1.length-1) == '/')
adamc@1260:         return s1 + s2;
adamc@1260:     else
adamc@1260:         return s1 + "/" + s2;
adamc@667: }
adamc@667: 
adamc@670: var channels = [];
adamc@670: 
adamc@670: function newQueue() {
adamc@1260:     return { front : null, back : null };
adamc@670: }
adamc@670: function enqueue(q, v) {
adamc@1260:     if (q.front == null) {
adamc@1260:         q.front = cons(v, null);
adamc@1260:         q.back = q.front;
adamc@1260:     } else {
adamc@1260:         var node = cons(v, null);
adamc@1260:         q.back.next = node;
adamc@1260:         q.back = node;
adamc@1260:     }
adamc@670: }
adamc@670: function dequeue(q) {
adamc@670:     if (q.front == null)
adamc@1260:         return null;
adamc@1260:     else {
adamc@1260:         var r = q.front.data;
adamc@1260:         q.front = q.front.next;
adamc@1260:         if (q.front == null)
adamc@1260:             q.back = null;
adamc@1260:         return r;
adamc@1260:     }
adamc@670: }
adamc@670: 
adamc@670: function newChannel() {
adamc@1260:     return { msgs : newQueue(), listeners : newQueue() };
adamc@670: }
adamc@670: 
adamc@667: function listener() {
adamc@1260:     var uri = path_join(url_prefix, ".msgs");
adamc@1260:     var xhr = getXHR();
adamc@1260:     var tid, orsc, onTimeout;
adamc@673: 
adamc@1260:     var connect = function () {
adamc@1260:         xhr.onreadystatechange = orsc;
adamc@1260:         tid = window.setTimeout(onTimeout, timeout * 500);
adamc@1260:         requestUri(xhr, uri, false);
adamc@1260:     }
adamc@673: 
adamc@1260:     orsc = function() {
adamc@1260:         if (xhr.readyState == 4) {
adamc@1260:             window.clearTimeout(tid);
adamc@673: 
adamc@1260:             var isok = false;
adamc@667: 
adamc@1260:             try {
adamc@1260:                 if (xhr.status == 200)
adamc@1260:                     isok = true;
adamc@1260:             } catch (e) { }
adamc@667: 
adamc@1260:             if (isok) {
adam@1447:                 var text = xhr.responseText;
adamc@1260:                 if (text == "")
adamc@1260:                     return;
adamc@1260:                 var lines = text.split("\n");
adamc@889: 
adam@1552:                 if (lines.length == 1 && lines[0] == "R") {
adam@1553:                     lameDuck = true;
adam@1553: 
adam@1552:                     if (isPost)
adam@1552:                         history.back();
adam@1552:                     else
adam@1552:                         location.reload();
adam@1552: 
adam@1552:                     return;
adam@1552:                 }
adam@1552: 
adamc@1260:                 if (lines.length < 2) {
adamc@1260:                     discon();
adamc@1260:                     return;
adamc@1260:                 }
adamc@1260: 
adam@1447:                 var messageReader = function(i) {
adam@1447:                     if (i+1 >= lines.length) {
adam@1447:                         xhrFinished(xhr);
adam@1447:                         connect();
adam@1447:                     }
adam@1447:                     else {
adam@1447:                         var chn = lines[i];
adam@1447:                         var msg = lines[i+1];
adamc@1260: 
adam@1447:                         if (chn == "E") {
adam@1447:                             eval(msg);
adam@1447:                             window.setTimeout(function() { messageReader(i+2); }, 0);
adam@1447:                         } else {
adam@1447:                             if (chn < 0)
adam@1447:                                 whine("Out-of-bounds channel in message from remote server");
adamc@1260: 
adam@1447:                             var ch;
adamc@1260: 
adam@1447:                             if (chn >= channels.length || channels[chn] == null) {
adam@1447:                                 ch = newChannel();
adam@1447:                                 channels[chn] = ch;
adam@1447:                             } else
adam@1447:                                 ch = channels[chn];
adamc@1260: 
adam@1447:                             var listener = dequeue(ch.listeners);
adam@1447:                             if (listener == null) {
adam@1447:                                 enqueue(ch.msgs, msg);
adam@1447:                             } else {
adam@1447:                                 try {
adam@1447:                                     listener(msg);
adam@1447:                                 } catch (v) {
adam@1447:                                     doExn(v);
adam@1447:                                 }
adam@1447:                             }
adam@1447: 
adam@1447:                             messageReader(i+2);
adamc@1260:                         }
adamc@1260:                     }
adamc@1260:                 }
adamc@1260: 
adam@1447:                 messageReader(0);
adamc@1260:             }
adamc@1260:             else {
adamc@1260:                 try {
adamc@1260:                     if (xhr.status != 0)
adamc@1260:                         servErr("Error querying remote server for messages: " + xhr.status);
adamc@1260:                 } catch (e) { }
adamc@1260:             }
adamc@729:         }
adamc@1260:     };
adamc@669: 
adamc@1260:     onTimeout = function() {
adamc@1260:         xhrFinished(xhr);
adamc@1260:         connect();
adamc@1260:     };
adamc@670: 
adamc@673:     connect();
adamc@667: }
adamc@670: 
adamc@670: function rv(chn, parse, k) {
adamc@1260:     if (chn == null)
adamc@1260:         return;
adamc@682: 
adamc@1260:     if (chn < 0)
adamc@1260:         whine("Out-of-bounds channel receive");
adamc@670: 
adamc@1260:     var ch;
adamc@670: 
adamc@1260:     if (chn >= channels.length || channels[chn] == null) {
adamc@1260:         ch = newChannel();
adamc@1260:         channels[chn] = ch;
adamc@1260:     } else
adamc@1260:         ch = channels[chn];
adamc@670: 
adamc@1260:     var msg = dequeue(ch.msgs);
adamc@1260:     if (msg == null) {
adamc@1260:         enqueue(ch.listeners, function(msg) { k(parse(msg)); });
adamc@1260:     } else {
adamc@1260:         try {
adamc@1260:             k(parse(msg));
adamc@1260:         } catch (v) {
adamc@1260:             doExn(v);
adamc@1260:         }
adamc@728:     }
adamc@670: }
adamc@693: 
adamc@978: function sl(ms, k) {
adamc@1260:     window.setTimeout(function() { k(null); }, ms);
adamc@1021: }
adamc@1021: 
adamc@1021: function sp(e) {
adamc@1260:     execF(e, null);
adamc@978: }
adamc@978: 
adamc@693: 
adamc@970: // The Ur interpreter
adamc@970: 
adamc@970: var urfuncs = [];
adamc@970: 
adamc@970: function lookup(env, n) {
adamc@1260:     while (env != null) {
adamc@1260:         if (n == 0)
adamc@1260:             return env.data;
adamc@1260:         else {
adamc@1260:             --n;
adamc@1260:             env = env.next;
adamc@1260:         }
adamc@970:     }
adamc@970: 
adamc@1260:     whine("Out-of-bounds Ur variable reference");
adamc@970: }
adamc@970: 
adamc@974: function execP(env, p, v) {
adamc@1260:     switch (p.c) {
adamc@1260:     case "w":
adamc@1260:         return env;
adamc@1260:     case "v":
adamc@1260:         return cons(v, env);
adamc@1260:     case "c":
adamc@1260:         if (v == p.v)
adamc@1260:             return env;
adamc@1260:         else
adamc@1260:             return false;
adamc@1260:     case "s":
adamc@1260:         if (v == null)
adamc@1260:             return false;
adamc@1260:         else
adamc@1260:             return execP(env, p.p, p.n ? v.v : v);
adamc@1260:     case "1":
adamc@1260:         if (v.n != p.n)
adamc@1260:             return false;
adamc@1260:         else
adamc@1260:             return execP(env, p.p, v.v);
adamc@1260:     case "r":
adamc@1260:         for (var fs = p.l; fs != null; fs = fs.next) {
adamc@1260:             env = execP(env, fs.data.p, v["_" + fs.data.n]);
adamc@1260:             if (env == false)
adamc@1260:                 return false;
adamc@1260:         }
adamc@1260:         return env;
adamc@1260:     default:
adamc@1260:         whine("Unknown Ur pattern kind" + p.c);
adamc@974:     }
adamc@974: }
adamc@974: 
adamc@970: function exec0(env, e) {
adamc@1260:     return exec1(env, null, e);
adamc@1020: }
adamc@1020: 
adamc@1020: function exec1(env, stack, e) {
adamc@1260:     var stack, usedK = false;
adamc@970: 
adamc@1260:     var saveEnv = function() {
adamc@1260:         if (stack.next != null && stack.next.data.c != "<")
adamc@1260:             stack = cons({c: "<", env: env}, stack.next);
adamc@1260:         else
adamc@1260:             stack = stack.next;
adamc@1260:     };
adamc@983: 
adamc@1260:     while (true) {
adamc@1260:         switch (e.c) {
adamc@1260:         case "c":
adamc@1260:             var v = e.v;
adamc@1260:             if (stack == null)
adamc@1260:                 return v;
adamc@1260:             var fr = stack.data;
adamc@970: 
adamc@1260:             switch (fr.c) {
adamc@1260:             case "s":
adamc@1260:                 e = {c: "c", v: {v: v}};
adamc@1260:                 stack = stack.next;
adamc@1260:                 break;
adamc@1260:             case "1":
adamc@1260:                 e = {c: "c", v: {n: fr.n, v: v}};
adamc@1260:                 stack = stack.next;
adamc@1260:                 break;
adamc@1260:             case "f":
adamc@1260:                 fr.args[fr.pos++] = v;
adamc@1260:                 if (fr.a == null) {
adamc@1260:                     var res;
adamc@1260:                     stack = stack.next;
adamc@1035: 
adamc@1260:                     if (fr.f.apply)
adamc@1260:                         res = fr.f.apply(null, fr.args);
adamc@1260:                     else if (fr.args.length == 0)
adamc@1260:                         res = fr.f();
adamc@1260:                     else if (fr.args.length == 1)
adamc@1260:                         res = fr.f(fr.args[0]);
adamc@1260:                     else if (fr.args.length == 2)
adamc@1260:                         res = fr.f(fr.args[0], fr.args[1]);
adamc@1260:                     else if (fr.args.length == 3)
adamc@1260:                         res = fr.f(fr.args[0], fr.args[1], fr.args[2]);
adamc@1260:                     else if (fr.args.length == 4)
adamc@1260:                         res = fr.f(fr.args[0], fr.args[1], fr.args[2], fr.args[3]);
adamc@1260:                     else if (fr.args.length == 5)
adamc@1260:                         res = fr.f(fr.args[0], fr.args[1], fr.args[2], fr.args[3], fr.args[4]);
adamc@1260:                     else
adamc@1260:                         whine("Native function has " + fr.args.length + " args, but there is no special case for that count.");
adamc@1035: 
adamc@1260:                     e = {c: "c", v: res};
adamc@1260:                     if (usedK) return null;
adamc@1260:                 } else {
adamc@1260:                     e = fr.a.data;
adamc@1260:                     fr.a = fr.a.next;
adamc@1260:                 }
adamc@1260:                 break;
adamc@1260:             case "a1":
adamc@1260:                 e = fr.x;
adamc@1260:                 stack = cons({c: "a2", f: v}, stack.next);
adamc@1260:                 break;
adamc@1260:             case "a2":
adamc@1260:                 if (fr.f == null)
adamc@1260:                     whine("Ur: applying null function");
adamc@1260:                 else if (fr.f.body) {
adamc@1260:                     saveEnv();
adamc@1260:                     env = cons(v, fr.f.env);
adamc@1260:                     e = fr.f.body;
adamc@1260:                 } else {
adamc@1260:                     e = {c: "c", v: fr.f(v)};
adamc@1260:                     stack = stack.next;
adamc@1260:                 }
adamc@1260:                 break;
adamc@1260:             case "<":
adamc@1260:                 env = fr.env;
adamc@1260:                 stack = stack.next;
adamc@1260:                 break;
adamc@1260:             case "r":
adamc@1260:                 fr.fs["_" + fr.n] = v;
adamc@1260:                 if (fr.l == null) {
adamc@1260:                     e = {c: "c", v: fr.fs};
adamc@1260:                     stack = stack.next;
adamc@1260:                 } else {
adamc@1260:                     fr.n = fr.l.data.n;
adamc@1260:                     e = fr.l.data.v;
adamc@1260:                     fr.l = fr.l.next;
adamc@1260:                 }
adamc@1260:                 break;
adamc@1260:             case ".":
adamc@1260:                 e = {c: "c", v: v["_" + fr.f]};
adamc@1260:                 stack = stack.next;
adamc@1260:                 break;
adamc@1260:             case ";":
adamc@1260:                 e = fr.e2;
adamc@1260:                 stack = stack.next;
adamc@1260:                 break;
adamc@1260:             case "=":
adamc@1260:                 saveEnv();
adamc@1260:                 env = cons(v, env);
adamc@1260:                 e = fr.e2;
adamc@1260:                 break;
adamc@1260:             case "m":
adamc@1260:                 var ps;
adamc@1260:                 for (ps = fr.p; ps != null; ps = ps.next) {
adamc@1260:                     var r = execP(env, ps.data.p, v);
adamc@1260:                     if (r != false) {
adamc@1260:                         saveEnv();
adamc@1260:                         env = r;
adamc@1260:                         e = ps.data.b;
adamc@1260:                         break;
adamc@1260:                     }
adamc@1260:                 }
adamc@1260:                 if (ps == null)
adamc@1260:                     whine("Match failure in Ur interpretation");
adamc@1260:                 break;
adamc@1260:             default:
adamc@1260:                 whine("Unknown Ur continuation kind " + fr.c);
adamc@1260:             }
adamc@1260: 
adamc@1260:             break;
adamc@1260:         case "v":
adamc@1260:             e = {c: "c", v: lookup(env, e.n)};
adamc@1260:             break;
adamc@1260:         case "n":
adamc@1260:             var idx = e.n;
adamc@1260:             e = urfuncs[idx];
adamc@1260:             if (e.c == "t")
adamc@1262:                 e = urfuncs[idx] = eval("(" + e.f + ")");
adamc@1260:             break;
adamc@1260:         case "s":
adamc@1260:             stack = cons({c: "s"}, stack);
adamc@1260:             e = e.v;
adamc@1260:             break;
adamc@1260:         case "1":
adamc@1260:             stack = cons({c: "1", n: e.n}, stack);
adamc@1260:             e = e.v;
adamc@1260:             break;
adamc@1260:         case "f":
adamc@1260:             if (e.a == null)
adamc@1260:                 e = {c: "c", v: (eval(e.f))()};
adamc@1260:             else {
adamc@1260:                 var args = [];
adamc@1260:                 stack = cons({c: "f", f: eval(e.f), args: args, pos: 0, a: e.a.next}, stack);
adamc@1260:                 if (!e.a.data.c) alert("[2] fr.f = " + e.f + "; 0 = " + e.a.data);
adamc@1260:                 e = e.a.data;
adamc@1260:             }
adamc@1260:             break;
adamc@1260:         case "l":
adamc@1260:             e = {c: "c", v: {env: env, body: e.b}};
adamc@1260:             break;
adamc@1260:         case "a":
adamc@1260:             stack = cons({c: "a1", x: e.x}, stack);
adamc@1260:             e = e.f;
adamc@1260:             break;
adamc@1260:         case "r":
adamc@1260:             if (e.l == null)
adamc@1260:                 whine("Empty Ur record in interpretation");
adamc@1260:             var fs = {};
adamc@1260:             stack = cons({c: "r", n: e.l.data.n, fs: fs, l: e.l.next}, stack);
adamc@1260:             e = e.l.data.v;
adamc@1260:             break;
adamc@1260:         case ".":
adamc@1260:             stack = cons({c: ".", f: e.f}, stack);
adamc@1260:             e = e.r;
adamc@1260:             break;
adamc@1260:         case ";":
adamc@1260:             stack = cons({c: ";", e2: e.e2}, stack);
adamc@1260:             e = e.e1;
adamc@1260:             break;
adamc@1260:         case "=":
adamc@1260:             stack = cons({c: "=", e2: e.e2}, stack);
adamc@1260:             e = e.e1;
adamc@1260:             break;
adamc@1260:         case "m":
adamc@1260:             stack = cons({c: "m", p: e.p}, stack);
adamc@1260:             e = e.e;
adamc@1260:             break;
adamc@1260:         case "e":
adamc@1260:             e = {c: "c", v: cs({c: "wc", env: env, body: e.e})};
adamc@1260:             break;
adamc@1260:         case "wc":
adamc@1260:             env = e.env;
adamc@1260:             e = e.body;
adamc@1260:             break;
adamc@1260:         case "K":
adamc@1260:             { var savedStack = stack.next, savedEnv = env;
adamc@1260:                 e = {c: "c", v: function(v) { return exec1(savedEnv, savedStack, {c: "c", v: v}); } };}
adamc@1260:             usedK = true;
adamc@1260:             break;      
adamc@1260:         default:
adamc@1260:             whine("Unknown Ur expression kind " + e.c);
adamc@970:         }
adamc@970:     }
adamc@970: }
adamc@970: 
adamc@976: function execD(e) {
adamc@1260:     return exec0(null, e);
adamc@976: }
adamc@976: 
adamc@970: function exec(e) {
adamc@1260:     var r = exec0(null, e);
adamc@970: 
adamc@1260:     if (r != null && r.body != null)
adamc@1260:         return function(v) { return exec0(cons(v, r.env), r.body); };
adamc@1260:     else
adamc@1260:         return r;
adamc@895: }
adamc@895: 
adamc@977: function execF(f, x) {
adamc@1260:     return exec0(cons(x, f.env), f.body);
adamc@977: }
adamc@977: 
adamc@895: 
adam@1290: // Wrappers
adam@1290: 
adam@1290: function confrm(s) {
adam@1290:     return confirm(s) ? true : false;
adam@1290: }
adam@1290: 
adam@1290: 
adamc@1323: // URL blessing
adamc@1323: 
adamc@1323: var urlRules = null;
adamc@1323: 
adamc@1323: function checkUrl(s) {
adamc@1323:     for (var r = urlRules; r; r = r.next) {
adamc@1323:         var ru = r.data;
adamc@1323:         if (ru.prefix ? s.indexOf(ru.pattern) == 0 : s == ru.pattern)
adamc@1323:             return ru.allow ? s : null;
adamc@1323:     }
adamc@1323: 
adamc@1323:     return null;
adamc@1323: }
adamc@1323: 
adamc@1323: function bless(s) {
adamc@1323:     u = checkUrl(s);
adamc@1323:     if (u == null)
adamc@1323:         er("Disallowed URL: " + s);
adamc@1323:     return u;
adamc@1323: }
adamc@1323: 
adam@1556: 
adam@1556: // ID generation
adam@1556: 
adam@1556: var nextId = 0;
adam@1556: 
adam@1556: function fresh() {
adam@1556:     return (--nextId).toString();
adam@1556: }
adam@1556: 
adamc@693: // App-specific code
adamc@693: