Initial commit

node_modules/graphlib-dot/lib/build-graph.js

@@ -0,0 +1,129 @@
+"use strict";
+
+var _ = require("./lodash"),
+    Graph = require("./graphlib").Graph;
+
+module.exports = buildGraph;
+
+function buildGraph(parseTree) {
+  var isDirected = parseTree.type !== "graph",
+      isMultigraph = !parseTree.strict,
+      defaultStack = [{ node: {}, edge: {} }],
+      id = parseTree.id,
+      g = new Graph({ directed: isDirected, multigraph: isMultigraph, compound: true });
+      g.setGraph(id === null ? {} : {id: id});
+  _.each(parseTree.stmts, function(stmt) { handleStmt(g, stmt, defaultStack); });
+  return g;
+}
+
+function handleStmt(g, stmt, defaultStack, sg) {
+  switch(stmt.type) {
+    case "node": handleNodeStmt(g, stmt, defaultStack, sg); break;
+    case "edge": handleEdgeStmt(g, stmt, defaultStack, sg); break;
+    case "subgraph": handleSubgraphStmt(g, stmt, defaultStack, sg); break;
+    case "attr": handleAttrStmt(g, stmt, defaultStack); break;
+    case "inlineAttr": handleInlineAttrsStmt(g, stmt, defaultStack, sg); break;
+  }
+}
+
+function handleNodeStmt(g, stmt, defaultStack, sg) {
+  var v = stmt.id,
+      attrs = stmt.attrs;
+  maybeCreateNode(g, v, defaultStack, sg);
+  _.merge(g.node(v), attrs);
+}
+
+function handleEdgeStmt(g, stmt, defaultStack, sg) {
+  var attrs = stmt.attrs,
+      prev, curr;
+  _.each(stmt.elems, function(elem) {
+    handleStmt(g, elem, defaultStack, sg);
+
+    switch(elem.type) {
+      case "node": curr = [elem.id]; break;
+      case "subgraph": curr = collectNodeIds(elem); break;
+    }
+
+    _.each(prev, function(v) {
+      _.each(curr, function(w) {
+        var name;
+        if (g.hasEdge(v, w) && g.isMultigraph()) {
+          name = _.uniqueId("edge");
+        }
+        if (!g.hasEdge(v, w, name)) {
+          g.setEdge(v, w, _.clone(_.last(defaultStack).edge), name);
+        }
+        _.merge(g.edge(v, w, name), attrs);
+      });
+    });
+
+    prev = curr;
+  });
+}
+
+function handleSubgraphStmt(g, stmt, defaultStack, sg) {
+  var id = stmt.id;
+  if (id === undefined) {
+    id = generateSubgraphId(g);
+  }
+
+  defaultStack.push(_.clone(_.last(defaultStack)));
+
+  maybeCreateNode(g, id, defaultStack, sg);
+
+  _.each(stmt.stmts, function(s) {
+    handleStmt(g, s, defaultStack, id);
+  });
+
+  // If there are no statements remove the subgraph
+  if (!g.children(id).length) {
+    g.removeNode(id);
+  }
+
+  defaultStack.pop();
+}
+
+function handleAttrStmt(g, stmt, defaultStack) {
+  _.merge(_.last(defaultStack)[stmt.attrType], stmt.attrs);
+}
+
+function handleInlineAttrsStmt(g, stmt, defaultStack, sg) {
+  _.merge(sg ? g.node(sg) : g.graph(), stmt.attrs);
+}
+
+function generateSubgraphId(g) {
+  var id;
+  do {
+    id = _.uniqueId("sg");
+  } while (g.hasNode(id));
+  return id;
+}
+
+function maybeCreateNode(g, v, defaultStack, sg) {
+  if (!g.hasNode(v)) {
+    g.setNode(v, _.clone(_.last(defaultStack).node));
+    g.setParent(v, sg);
+  }
+}
+
+// Collect all nodes involved in a subgraph statement
+function collectNodeIds(stmt) {
+  var ids = {},
+      stack = [],
+      curr;
+
+  var push = stack.push.bind(stack);
+
+  push(stmt);
+  while(stack.length) {
+    curr = stack.pop();
+    switch(curr.type) {
+      case "node": ids[curr.id] = true; break;
+      case "edge": _.each(curr.elems, push); break;
+      case "subgraph": _.each(curr.stmts, push); break;
+    }
+  }
+
+  return _.keys(ids);
+}
+