Add simplification of nodes

3 files changed, 68 insertions, 3 deletions

diff --git a/lib/html/ast.js b/lib/html/ast.js
index 25f4874..afecfce 100644
--- a/lib/html/ast.js
+++ b/lib/html/ast.js
@@ -1,5 +1,8 @@
 var _ = require("underscore");
 
+var htmlPaths = require("../html-paths");
+
+
 function fragment(children) {
     return {
         type: "fragment",
@@ -8,10 +11,15 @@ function fragment(children) {
 }
 
 function element(tagName, attributes, children) {
+    return elementWithTag(
+        htmlPaths.element(tagName, attributes, {fresh: true}),
+        children);
+}
+
+function elementWithTag(tag, children) {
     return {
         type: "element",
-        tagName: tagName,
-        attributes: attributes,
+        tag: tag,
         children: collapseFragments(children)
     };
 }
@@ -31,4 +39,5 @@ function collapseFragments(elements) {
 
 exports.fragment = fragment;
 exports.element = element;
+exports.elementWithTag = elementWithTag;
 exports.text = text;
diff --git a/lib/html/index.js b/lib/html/index.js
index f9e957a..41d348f 100644
--- a/lib/html/index.js
+++ b/lib/html/index.js
@@ -1,5 +1,17 @@
-var ast = require("./ast.js");
+var ast = require("./ast");
 
 exports.fragment = ast.fragment;
 exports.element = ast.element;
+exports.elementWithTag = ast.elementWithTag;
 exports.text = ast.text;
+
+function pathToNode(path, children) {
+    var result = ast.fragment(children);
+    for (var index = path.length - 1; index >= 0; index--) {
+        result = ast.elementWithTag(path[index], [result]);
+    }
+    return result;
+}
+
+exports.pathToNode = pathToNode;
+exports.simplify = require("./simplify");
diff --git a/lib/html/simplify.js b/lib/html/simplify.js
new file mode 100644
index 0000000..52a1b0a
--- /dev/null
+++ b/lib/html/simplify.js
@@ -0,0 +1,44 @@
+var _ = require("underscore");
+
+var ast = require("./ast");
+
+function simplify(node) {
+    return simplifiers[node.type](node);
+};
+
+var simplifiers = {
+    fragment: simplifyFragment,
+    element: simplifyElement,
+    text: simplifyText
+};
+
+function simplifyFragment(node) {
+    return ast.fragment(simplifyNodes(node.children));
+}
+
+function simplifyElement(node) {
+    return ast.elementWithTag(node.tag, simplifyNodes(node.children));
+}
+
+function simplifyText(node) {
+    return node;
+}
+
+function simplifyNodes(nodes) {
+    var children = [];
+    
+    nodes.map(simplify).forEach(function(child) {
+        var lastChild = children[children.length - 1];
+        if (child.type === "element" && !child.tag.fresh && lastChild && _.isEqual(lastChild.tag, child.tag)) {
+            child.children.forEach(function(grandChild) {
+                // Mutation is fine since simplifying elements create a copy of the children.
+                lastChild.children.push(grandChild);
+            });
+        } else {
+            children.push(child);
+        }
+    });
+    return children;
+}
+
+module.exports = simplify;