Work on inline attributes

plug-api/lib/attribute.ts

@@ -0,0 +1,51 @@
+import {
+  findNodeOfType,
+  ParseTree,
+  replaceNodesMatching,
+} from "$sb/lib/tree.ts";
+
+export type Attribute = {
+  name: string;
+  value: string;
+};
+
+const numberRegex = /^-?\d+(\.\d+)?$/;
+
+/**
+ * Extracts attributes from a tree, optionally cleaning them out of the tree.
+ * @param tree tree to extract attributes from
+ * @param clean whether or not to clean out the attributes from the tree
+ * @returns mapping from attribute name to attribute value
+ */
+export function extractAttributes(
+  tree: ParseTree,
+  clean: boolean,
+): Record<string, any> {
+  const attributes: Record<string, any> = {};
+  replaceNodesMatching(tree, (n) => {
+    if (n.type === "ListItem") {
+      // Find top-level only, no nested lists
+      return n;
+    }
+    if (n.type === "Attribute") {
+      const nameNode = findNodeOfType(n, "AttributeName");
+      const valueNode = findNodeOfType(n, "AttributeValue");
+      if (nameNode && valueNode) {
+        let val: any = valueNode.children![0].text!;
+        if (numberRegex.test(val)) {
+          val = +val;
+        }
+        attributes[nameNode.children![0].text!] = val;
+      }
+      // Remove from tree
+      if (clean) {
+        return null;
+      } else {
+        return n;
+      }
+    }
+    // Go on...
+    return undefined;
+  });
+  return attributes;
+}