experimental reversed flag

Author: qfox

lib/bem-graph.js

@@ -23,7 +23,7 @@ class BemGraph {
     naturalDependenciesOf(entities, tech) {
         return this.dependenciesOf(this._sortNaturally(entities), tech);
     }
-    dependenciesOf(entities, tech) {
+    dependenciesOf(entities, tech, reversed) {
         if (!Array.isArray(entities)) {
             entities = [entities];
         }
@@ -40,10 +40,7 @@ class BemGraph {
         }, []);
 
         // Recommended order
-        const _positions = vertices.reduce((res, e, pos) => { res[e.id] = pos + 1; return res; }, {});
-        const _sort = (a, b) => _positions[a.id] - _positions[b.id];
-
-        const iter = resolve(this._mixedGraph, vertices, tech, _sort);
+        const iter = resolve(this._mixedGraph, vertices, tech, reversed);
         const arr = Array.from(iter);
 
         // TODO: returns iterator
@@ -61,6 +58,9 @@ class BemGraph {
             return obj;
         }).filter(Boolean);
     }
+    reverseDependenciesOf(entities, tech) {
+        return this.dependenciesOf(entities, tech, true);
+    }
     naturalize() {
         const mixedGraph = this._mixedGraph;
 

lib/mixed-graph-resolve.js

@@ -64,7 +64,10 @@ class TopoGroups {
     }
 }
 
-function resolve(mixedGraph, startVertices, tech, backsort) {
+function resolve(mixedGraph, startVertices, tech, reverse) {
+    const _positions = startVertices.reduce((res, e, pos) => { res[e.id] = pos + 1; return res; }, {});
+    const backsort = (a, b) => _positions[a.id] - _positions[b.id];
+
     const orderedSuccessors = []; // L ← Empty list that will contain the sorted nodes
     const _orderedVisits = {}; // Hash with visiting flags: temporary - false, permanently - true
     const unorderedSuccessors = new VertexSet(); // The rest nodes
@@ -74,7 +77,7 @@ function resolve(mixedGraph, startVertices, tech, backsort) {
     // ... while there are unmarked nodes do
     startVertices.forEach(v => visit(v, false));
 
-    const _orderedSuccessors = Array.from(new VertexSet(orderedSuccessors.reverse()));
+    const _orderedSuccessors = reverse ? [] : Array.from(new VertexSet(orderedSuccessors.reverse()));
     const _unorderedSuccessors = Array.from(unorderedSuccessors).sort(backsort);
 
     // console.log({topogroups, ordered: Array.from(_orderedSuccessors).map(v => v.id), unordered: Array.from(_unorderedSuccessors).map(v => v.id)});
@@ -115,7 +118,7 @@ function resolve(mixedGraph, startVertices, tech, backsort) {
         topo.lookupCreate(fromVertex.id);
 
         // ... for each node m with an edge from n to m do
-        const orderedDirectSuccessors = mixedGraph.directSuccessors(fromVertex, { ordered: true, tech });
+        const orderedDirectSuccessors = reverse ? [] : mixedGraph.directSuccessors(fromVertex, { ordered: true, tech });
 
         for (let successor of orderedDirectSuccessors) {
             if (successor.id === fromVertex.id) { // TODO: Filter loops earlier
@@ -146,7 +149,7 @@ function resolve(mixedGraph, startVertices, tech, backsort) {
         weak || orderedSuccessors.unshift(fromVertex);
         weak && unorderedSuccessors.add(fromVertex);
 
-        const unorderedDirectSuccessors = mixedGraph.directSuccessors(fromVertex, { ordered: false, tech });
+        const unorderedDirectSuccessors = mixedGraph.directSuccessors(fromVertex, { ordered: false, tech, reversed: reverse });
 
         for (let successor of unorderedDirectSuccessors) {
             // console.log('unordered', successor.id);

lib/mixed-graph.js

@@ -18,6 +18,7 @@ module.exports = class MixedGraph {
         this._vertices = new VertexSet();
         this._orderedGraphMap = new Map();
         this._unorderedGraphMap = new Map();
+        this._reverseGraphMap = new Map();
     }
     addVertex(vertex) {
         this._vertices.add(vertex);
@@ -51,6 +52,17 @@ module.exports = class MixedGraph {
 
         subgraph.addEdge(fromVertex, toVertex);
 
+        let reverseSubgraph = this._getSubgraph({ tech, reversed: true });
+
+        // Create DirectedGraph for each tech
+        if (!reverseSubgraph) {
+            reverseSubgraph = new DirectedGraph();
+
+            this._reverseGraphMap.set(tech, reverseSubgraph);
+        }
+
+        reverseSubgraph.addEdge(toVertex, fromVertex);
+
         return this;
     }
     /**
@@ -86,7 +98,8 @@ module.exports = class MixedGraph {
         );
     }
     _getGraphMap(data) {
-        return data.ordered ? this._orderedGraphMap : this._unorderedGraphMap;
+        return data.reversed ? this._reverseGraphMap
+            : data.ordered ? this._orderedGraphMap : this._unorderedGraphMap;
     }
     _getSubgraph(data) {
         return this._getGraphMap(data).get(data.tech);