rename haskell -> tidal

packages/tidal/graph.mjs

@@ -0,0 +1,43 @@
+import { Graphviz } from '@hpcc-js/wasm';
+import toDot from 'jgf-dot';
+
+const graphvizLoaded = Graphviz.load();
+
+function walk(node, branch = [0], parent) {
+  let nodes = [];
+  let edges = [];
+  const color = 'white';
+  const current = {
+    id: branch.join('-'),
+    color,
+    fontcolor: color,
+    label: node.type.replace('\\', 'lambda'), // backslash kills graphviz..
+  };
+  nodes.push(current);
+  parent && edges.push({ source: parent.id, target: current.id, color });
+  if (node.children.length) {
+    node.children.forEach((child, j) => {
+      const { nodes: childNodes, edges: childEdges } = walk(child, branch.concat([j]), current);
+      nodes = nodes.concat(childNodes || []);
+      edges = edges.concat(childEdges || []);
+    });
+  }
+  return { nodes, edges };
+}
+
+export async function renderGraph(tree, container) {
+  const { nodes, edges } = walk(tree.rootNode);
+  const graphviz = await graphvizLoaded;
+  let dot = toDot({
+    graph: {
+      nodes,
+      edges,
+    },
+  });
+  dot = dot.split('\n');
+  dot.splice(1, 0, 'bgcolor="transparent"');
+  dot.splice(1, 0, 'color="white"');
+  dot = dot.join('\n');
+  const svg = await graphviz.layout(dot, 'svg', 'dot', {});
+  container.innerHTML = svg;
+}