Initial project import

tools/v/vlib/x/markdown/node.v

@@ -0,0 +1,118 @@
+// Copyright 2026 The V Language. All rights reserved.
+// Use of this source code is governed by an MIT license
+// that can be found in the LICENSE file.
+module markdown
+
+import strings
+
+// NodeKind identifies what kind of AST node a Node represents.
+pub enum NodeKind {
+	document
+	heading
+	paragraph
+	blockquote
+	list
+	list_item
+	code_block
+	fenced_code
+	thematic_break
+	html_block
+	link_ref_def
+	table
+	table_head
+	table_body
+	table_row
+	table_cell
+	definition_list
+	definition_term
+	definition_desc
+	footnote_def
+	text
+	emphasis
+	strong
+	code_span
+	link
+	image
+	autolink
+	raw_html
+	hard_break
+	soft_break
+	strikethrough
+	footnote_ref
+	task_checkbox
+}
+
+// Alignment is the text alignment of a table cell column.
+pub enum Alignment {
+	none_
+	left
+	center
+	right
+}
+
+// Node is a node in the parsed markdown AST.
+// A document is a tree of Nodes with .document as the root.
+@[heap]
+pub struct Node {
+pub mut:
+	kind       NodeKind
+	level      int
+	is_tight   bool
+	is_ordered bool
+	list_start int = 1
+	fence_info string
+	literal    string
+	dest       string
+	title      string
+	label      string
+	checked    bool
+	align      Alignment
+	id         string
+	fn_label   string
+	fn_index   int
+	children   []&Node
+}
+
+// new_node allocates and returns a new Node of the given kind.
+pub fn new_node(kind NodeKind) &Node {
+	return &Node{
+		kind: kind
+	}
+}
+
+// append_child appends child as the last child of n.
+pub fn (mut n Node) append_child(child &Node) {
+	n.children << child
+}
+
+// text_content returns the plain-text content of this node and all descendants,
+// concatenated in document order.
+pub fn (n &Node) text_content() string {
+	match n.kind {
+		.text, .code_span, .raw_html {
+			return n.literal
+		}
+		else {
+			mut sb := strings.new_builder(64)
+			for child in n.children {
+				sb.write_string(child.text_content())
+			}
+			return sb.str()
+		}
+	}
+}
+
+// walk traverses n and all its descendants in pre-order (root before children).
+// The callback f receives each node; return false from f to stop traversal early.
+// walk itself returns false if traversal was stopped, true otherwise.
+pub fn (n &Node) walk(f fn (&Node) bool) bool {
+	if !f(n) {
+		return false
+	}
+	for child in n.children {
+		if !child.walk(f) {
+			return false
+		}
+	}
+	return true
+}