1 files changed, 34 insertions, 0 deletions
diff --git a/packages/gitbook/src/parse/walkSummary.js b/packages/gitbook/src/parse/walkSummary.js
new file mode 100644
index 0000000..47feb1f
--- /dev/null
+++ b/packages/gitbook/src/parse/walkSummary.js
@@ -0,0 +1,34 @@
+const Promise = require('../utils/promise');
+
+/**
+    Walk over a list of articles
+
+    @param {List<Article>} articles
+    @param {Function(article)}
+    @return {Promise}
+*/
+function walkArticles(articles, fn) {
+    return Promise.forEach(articles, function(article) {
+        return Promise(fn(article))
+        .then(function() {
+            return walkArticles(article.getArticles(), fn);
+        });
+    });
+}
+
+/**
+    Walk over summary and execute "fn" on each article
+
+    @param {Summary} summary
+    @param {Function(article)}
+    @return {Promise}
+*/
+function walkSummary(summary, fn) {
+    const parts = summary.getParts();
+
+    return Promise.forEach(parts, function(part) {
+        return walkArticles(part.getArticles(), fn);
+    });
+}
+
+module.exports = walkSummary;