42 lines
1.4 KiB
JavaScript
42 lines
1.4 KiB
JavaScript
(function() {
|
|
|
|
// Returns boolean indicating if the swap was successful.
|
|
// Requires that the two signal graphs have exactly the same
|
|
// structure.
|
|
ElmRuntime.swap = function(from, to) {
|
|
function similar(nodeOld,nodeNew) {
|
|
var idOkay = nodeOld.id === nodeNew.id;
|
|
var lengthOkay = nodeOld.kids.length === nodeNew.kids.length;
|
|
return idOkay && lengthOkay;
|
|
}
|
|
function swap(nodeOld,nodeNew) {
|
|
nodeNew.value = nodeOld.value;
|
|
return true;
|
|
}
|
|
var canSwap = depthFirstTraversals(similar, from.inputs, to.inputs);
|
|
if (canSwap) { depthFirstTraversals(swap, from.inputs, to.inputs); }
|
|
from.node.parentNode.replaceChild(to.node, from.node);
|
|
return canSwap;
|
|
}
|
|
|
|
// Returns false if the node operation f ever fails.
|
|
function depthFirstTraversals(f, queueOld, queueNew) {
|
|
if (queueOld.length !== queueNew.length) return false;
|
|
queueOld = queueOld.slice(0);
|
|
queueNew = queueNew.slice(0);
|
|
|
|
var seen = [];
|
|
while (queueOld.length > 0 && queueNew.length > 0) {
|
|
var nodeOld = queueOld.pop();
|
|
var nodeNew = queueNew.pop();
|
|
if (seen.indexOf(nodeOld.id) < 0) {
|
|
if (!f(nodeOld, nodeNew)) return false;
|
|
queueOld = queueOld.concat(nodeOld.kids);
|
|
queueNew = queueNew.concat(nodeNew.kids);
|
|
seen.push(nodeOld.id);
|
|
}
|
|
}
|
|
return true;
|
|
}
|
|
|
|
}());
|