1 files changed, 122 insertions, 0 deletions
diff --git a/cmark/src/iterator.c b/cmark/src/iterator.c
new file mode 100644
index 0000000000..cc428285ea
--- /dev/null
+++ b/cmark/src/iterator.c
@@ -0,0 +1,122 @@
+#include <assert.h>
+#include <stdbool.h>
+#include <stdlib.h>
+
+#include "node.h"
+#include "cmark.h"
+#include "iterator.h"
+
+static const int S_leaf_mask =
+    (1 << CMARK_NODE_HTML_BLOCK) | (1 << CMARK_NODE_THEMATIC_BREAK) |
+    (1 << CMARK_NODE_CODE_BLOCK) | (1 << CMARK_NODE_TEXT) |
+    (1 << CMARK_NODE_SOFTBREAK) | (1 << CMARK_NODE_LINEBREAK) |
+    (1 << CMARK_NODE_CODE) | (1 << CMARK_NODE_HTML_INLINE);
+
+cmark_iter *cmark_iter_new(cmark_node *root) {
+  if (root == NULL) {
+    return NULL;
+  }
+  cmark_mem *mem = root->mem;
+  cmark_iter *iter = (cmark_iter *)mem->calloc(1, sizeof(cmark_iter));
+  iter->mem = mem;
+  iter->root = root;
+  iter->cur.ev_type = CMARK_EVENT_NONE;
+  iter->cur.node = NULL;
+  iter->next.ev_type = CMARK_EVENT_ENTER;
+  iter->next.node = root;
+  return iter;
+}
+
+void cmark_iter_free(cmark_iter *iter) { iter->mem->free(iter); }
+
+static bool S_is_leaf(cmark_node *node) {
+  return ((1 << node->type) & S_leaf_mask) != 0;
+}
+
+cmark_event_type cmark_iter_next(cmark_iter *iter) {
+  cmark_event_type ev_type = iter->next.ev_type;
+  cmark_node *node = iter->next.node;
+
+  iter->cur.ev_type = ev_type;
+  iter->cur.node = node;
+
+  if (ev_type == CMARK_EVENT_DONE) {
+    return ev_type;
+  }
+
+  /* roll forward to next item, setting both fields */
+  if (ev_type == CMARK_EVENT_ENTER && !S_is_leaf(node)) {
+    if (node->first_child == NULL) {
+      /* stay on this node but exit */
+      iter->next.ev_type = CMARK_EVENT_EXIT;
+    } else {
+      iter->next.ev_type = CMARK_EVENT_ENTER;
+      iter->next.node = node->first_child;
+    }
+  } else if (node == iter->root) {
+    /* don't move past root */
+    iter->next.ev_type = CMARK_EVENT_DONE;
+    iter->next.node = NULL;
+  } else if (node->next) {
+    iter->next.ev_type = CMARK_EVENT_ENTER;
+    iter->next.node = node->next;
+  } else if (node->parent) {
+    iter->next.ev_type = CMARK_EVENT_EXIT;
+    iter->next.node = node->parent;
+  } else {
+    assert(false);
+    iter->next.ev_type = CMARK_EVENT_DONE;
+    iter->next.node = NULL;
+  }
+
+  return ev_type;
+}
+
+void cmark_iter_reset(cmark_iter *iter, cmark_node *current,
+                      cmark_event_type event_type) {
+  iter->next.ev_type = event_type;
+  iter->next.node = current;
+  cmark_iter_next(iter);
+}
+
+cmark_node *cmark_iter_get_node(cmark_iter *iter) { return iter->cur.node; }
+
+cmark_event_type cmark_iter_get_event_type(cmark_iter *iter) {
+  return iter->cur.ev_type;
+}
+
+cmark_node *cmark_iter_get_root(cmark_iter *iter) { return iter->root; }
+
+void cmark_consolidate_text_nodes(cmark_node *root) {
+  if (root == NULL) {
+    return;
+  }
+  cmark_iter *iter = cmark_iter_new(root);
+  cmark_strbuf buf = CMARK_BUF_INIT(iter->mem);
+  cmark_event_type ev_type;
+  cmark_node *cur, *tmp, *next;
+
+  while ((ev_type = cmark_iter_next(iter)) != CMARK_EVENT_DONE) {
+    cur = cmark_iter_get_node(iter);
+    if (ev_type == CMARK_EVENT_ENTER && cur->type == CMARK_NODE_TEXT &&
+        cur->next && cur->next->type == CMARK_NODE_TEXT) {
+      cmark_strbuf_clear(&buf);
+      cmark_strbuf_put(&buf, cur->data, cur->len);
+      tmp = cur->next;
+      while (tmp && tmp->type == CMARK_NODE_TEXT) {
+        cmark_iter_next(iter); // advance pointer
+        cmark_strbuf_put(&buf, tmp->data, tmp->len);
+        cur->end_column = tmp->end_column;
+        next = tmp->next;
+        cmark_node_free(tmp);
+        tmp = next;
+      }
+      iter->mem->free(cur->data);
+      cur->len = buf.size;
+      cur->data = cmark_strbuf_detach(&buf);
+    }
+  }
+
+  cmark_strbuf_free(&buf);
+  cmark_iter_free(iter);
+}