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- "use strict";
-
- var PERMANENT_MARKER = 2;
- var TEMPORARY_MARKER = 1;
-
- function createError(node, graph) {
- var er = new Error("Nondeterministic import's order");
-
- var related = graph[node];
- var relatedNode = related.find(function (relatedNode) {
- return graph[relatedNode].indexOf(node) > -1;
- });
-
- er.nodes = [node, relatedNode];
-
- return er;
- }
-
- function walkGraph(node, graph, state, result, strict) {
- if (state[node] === PERMANENT_MARKER) return;
- if (state[node] === TEMPORARY_MARKER) {
- if (strict) return createError(node, graph);
- return;
- }
-
- state[node] = TEMPORARY_MARKER;
-
- var children = graph[node];
- var length = children.length;
-
- for (var i = 0; i < length; ++i) {
- var er = walkGraph(children[i], graph, state, result, strict);
- if (er instanceof Error) return er;
- }
-
- state[node] = PERMANENT_MARKER;
-
- result.push(node);
- }
-
- function topologicalSort(graph, strict) {
- var result = [];
- var state = {};
-
- var nodes = Object.keys(graph);
- var length = nodes.length;
-
- for (var i = 0; i < length; ++i) {
- var er = walkGraph(nodes[i], graph, state, result, strict);
- if (er instanceof Error) return er;
- }
-
- return result;
- }
-
- module.exports = topologicalSort;
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