Initial project import

tools/v/vlib/x/markdown/plaintext.v

@@ -0,0 +1,287 @@
+// 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
+
+// PlainTextRenderer renders a parsed markdown AST to UTF-8 console-friendly text.
+struct PlainTextRenderer {
+	opts    Options
+	ref_map map[string]LinkRef
+mut:
+	sb strings.Builder
+	// footnote tracking
+	fn_order []string
+	fn_nodes map[string]&Node
+	// list tracking
+	list_depth int
+	list_nums  []int
+}
+
+// render renders the document node to plain text.
+pub fn (mut r PlainTextRenderer) render(doc &Node) string {
+	r.sb = strings.new_builder(1024)
+	if r.opts.footnotes {
+		for child in doc.children {
+			if child.kind == .footnote_def {
+				r.fn_nodes[child.fn_label] = child
+			}
+		}
+	}
+	r.render_children(doc)
+	if r.opts.footnotes && r.fn_order.len > 0 {
+		r.render_footnotes_section()
+	}
+	return r.sb.str().trim_right('\n') + '\n'
+}
+
+fn (mut r PlainTextRenderer) render_node(node &Node) {
+	match node.kind {
+		.document { r.render_children(node) }
+		.heading { r.render_heading(node) }
+		.paragraph { r.render_paragraph(node) }
+		.blockquote { r.render_blockquote(node) }
+		.list { r.render_list(node) }
+		.list_item { r.render_list_item(node) }
+		.code_block, .fenced_code { r.render_code_block(node) }
+		.thematic_break { r.sb.write_string('---\n') }
+		.html_block { r.render_html_block(node) }
+		.link_ref_def, .footnote_def {}
+		.table { r.render_table(node) }
+		.table_head, .table_body { r.render_children(node) }
+		.table_row { r.render_table_row(node) }
+		.table_cell { r.render_table_cell(node) }
+		.definition_list { r.render_children(node) }
+		.definition_term { r.render_definition_term(node) }
+		.definition_desc { r.render_definition_desc(node) }
+		.text { r.render_text(node) }
+		.emphasis { r.render_wrapped(node, '*') }
+		.strong { r.render_wrapped(node, '**') }
+		.code_span { r.sb.write_string('`' + node.literal + '`') }
+		.link { r.render_link(node) }
+		.image { r.render_image(node) }
+		.autolink { r.sb.write_string(node.literal) }
+		.raw_html { r.render_raw_html(node) }
+		.hard_break, .soft_break { r.sb.write_string('\n') }
+		.strikethrough { r.render_wrapped(node, '~~') }
+		.task_checkbox { r.render_task_checkbox(node) }
+		.footnote_ref { r.render_footnote_ref(node) }
+	}
+}
+
+fn (mut r PlainTextRenderer) render_children(node &Node) {
+	for child in node.children {
+		r.render_node(child)
+	}
+}
+
+fn (mut r PlainTextRenderer) render_inline(src string) {
+	nodes := parse_inline(src, r.opts, r.ref_map)
+	for node in nodes {
+		r.render_node(node)
+	}
+}
+
+fn (mut r PlainTextRenderer) render_heading(node &Node) {
+	r.sb.write_string('${'#'.repeat(node.level)} ')
+	if node.children.len > 0 {
+		r.render_children(node)
+	} else {
+		r.render_inline(node.literal)
+	}
+	r.sb.write_string('\n\n')
+}
+
+fn (mut r PlainTextRenderer) render_paragraph(node &Node) {
+	if node.children.len > 0 {
+		r.render_children(node)
+	} else {
+		r.render_inline(node.literal)
+	}
+	r.sb.write_string('\n')
+}
+
+fn (mut r PlainTextRenderer) render_blockquote(node &Node) {
+	mut inner := strings.new_builder(128)
+	mut rr := PlainTextRenderer{
+		opts:     r.opts
+		ref_map:  r.ref_map
+		fn_order: r.fn_order.clone()
+		fn_nodes: r.fn_nodes
+	}
+	rr.sb = inner
+	rr.render_children(node)
+	for line in rr.sb.str().trim_right('\n').split('\n') {
+		r.sb.write_string('> ${line}\n')
+	}
+	// Keep footnote reference order discovered inside the blockquote.
+	r.fn_order = rr.fn_order
+	r.sb.write_string('\n')
+}
+
+fn (mut r PlainTextRenderer) render_list(node &Node) {
+	r.list_depth++
+	if node.is_ordered {
+		r.list_nums << node.list_start
+	} else {
+		r.list_nums << 0
+	}
+	r.render_children(node)
+	r.list_nums.delete_last()
+	r.list_depth--
+	if r.list_depth == 0 {
+		r.sb.write_string('\n')
+	}
+}
+
+fn (mut r PlainTextRenderer) render_list_item(node &Node) {
+	indent := '  '.repeat(if r.list_depth > 0 { r.list_depth - 1 } else { 0 })
+	idx := r.list_nums.len - 1
+	marker := if idx >= 0 && r.list_nums[idx] > 0 {
+		m := '${r.list_nums[idx]}. '
+		r.list_nums[idx]++
+		m
+	} else {
+		'- '
+	}
+	r.sb.write_string(indent + marker)
+	for i, child in node.children {
+		if i > 0 {
+			r.sb.write_string(' ')
+		}
+		if child.kind == .paragraph {
+			if child.children.len > 0 {
+				r.render_children(child)
+			} else {
+				r.render_inline(child.literal)
+			}
+		} else if child.kind == .list {
+			r.sb.write_string('\n')
+			r.render_node(child)
+		} else {
+			r.render_node(child)
+		}
+	}
+	r.sb.write_string('\n')
+}
+
+fn (mut r PlainTextRenderer) render_code_block(node &Node) {
+	r.sb.write_string('```\n')
+	r.sb.write_string(node.literal.trim_right('\n'))
+	r.sb.write_string('\n```\n\n')
+}
+
+fn (mut r PlainTextRenderer) render_html_block(node &Node) {
+	if r.opts.renderer_opts.unsafe_ {
+		r.sb.write_string(node.literal)
+	} else {
+		r.sb.write_string('[raw HTML omitted]\n')
+	}
+}
+
+fn (mut r PlainTextRenderer) render_table(node &Node) {
+	r.render_children(node)
+	r.sb.write_string('\n')
+}
+
+fn (mut r PlainTextRenderer) render_table_row(node &Node) {
+	r.render_children(node)
+	r.sb.write_string('\n')
+}
+
+fn (mut r PlainTextRenderer) render_table_cell(node &Node) {
+	r.sb.write_string(node.literal.trim_space())
+	r.sb.write_string(' | ')
+}
+
+fn (mut r PlainTextRenderer) render_definition_term(node &Node) {
+	r.render_inline(node.literal)
+	r.sb.write_string('\n')
+	for child in node.children {
+		r.render_node(child)
+	}
+}
+
+fn (mut r PlainTextRenderer) render_definition_desc(node &Node) {
+	r.sb.write_string('  - ')
+	r.render_inline(node.literal)
+	r.sb.write_string('\n')
+}
+
+fn (mut r PlainTextRenderer) render_text(node &Node) {
+	content := if r.opts.typographer {
+		smart_punctuate(node.literal)
+	} else {
+		node.literal
+	}
+	r.sb.write_string(content)
+}
+
+fn (mut r PlainTextRenderer) render_wrapped(node &Node, marker string) {
+	r.sb.write_string(marker)
+	r.render_children(node)
+	r.sb.write_string(marker)
+}
+
+fn (mut r PlainTextRenderer) render_link(node &Node) {
+	r.render_children(node)
+	if node.dest.len > 0 {
+		r.sb.write_string(' (${node.dest})')
+	}
+}
+
+fn (mut r PlainTextRenderer) render_image(node &Node) {
+	alt := node.text_content().trim_space()
+	if alt.len == 0 {
+		r.sb.write_string('[image]')
+	} else {
+		r.sb.write_string('[image: ${alt}]')
+	}
+	if node.dest.len > 0 {
+		r.sb.write_string(' (${node.dest})')
+	}
+}
+
+fn (mut r PlainTextRenderer) render_raw_html(node &Node) {
+	if r.opts.renderer_opts.unsafe_ {
+		r.sb.write_string(node.literal)
+	}
+}
+
+fn (mut r PlainTextRenderer) render_task_checkbox(node &Node) {
+	r.sb.write_string(if node.checked { '☑' } else { '☐' })
+}
+
+fn (mut r PlainTextRenderer) render_footnote_ref(node &Node) {
+	label := node.fn_label
+	mut idx := 0
+	for i, l in r.fn_order {
+		if l == label {
+			idx = i + 1
+			break
+		}
+	}
+	if idx == 0 {
+		r.fn_order << label
+		idx = r.fn_order.len
+	}
+	r.sb.write_string('[${idx}]')
+}
+
+fn (mut r PlainTextRenderer) render_footnotes_section() {
+	r.sb.write_string('\nFootnotes:\n')
+	for label in r.fn_order {
+		fn_node := r.fn_nodes[label] or { continue }
+		mut idx := 0
+		for i, l in r.fn_order {
+			if l == label {
+				idx = i + 1
+				break
+			}
+		}
+		r.sb.write_string('[${idx}] ')
+		r.render_inline(fn_node.literal)
+		r.sb.write_string('\n')
+	}
+}