Added xml writer, to dump the AST in XML.

This is a work-in-progress.

CommonMark.dtd gives the DTD for the generated XML.

Closes #53.

1 files changed, 140 insertions, 0 deletions

diff --git a/src/xml.c b/src/xml.c
new file mode 100644
index 0000000..86fb6d4
--- /dev/null
+++ b/src/xml.c
@@ -0,0 +1,140 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <assert.h>
+
+#include "config.h"
+#include "cmark.h"
+#include "node.h"
+#include "buffer.h"
+#include "houdini.h"
+
+// Functions to convert cmark_nodes to XML strings.
+
+static void escape_xml(cmark_strbuf *dest, const unsigned char *source, int length)
+{
+	if (source != NULL) {
+		if (length < 0)
+			length = strlen((char *)source);
+
+		houdini_escape_html0(dest, source, (size_t)length, 0);
+	}
+}
+
+struct render_state {
+	cmark_strbuf* xml;
+	int indent;
+};
+
+static inline void indent(struct render_state *state)
+{
+	int i;
+	for (i = 0; i < state->indent; i++) {
+		cmark_strbuf_putc(state->xml, ' ');
+	}
+}
+
+static int
+S_render_node(cmark_node *node, cmark_event_type ev_type, void *vstate)
+{
+	struct render_state *state = vstate;
+	cmark_strbuf *xml = state->xml;
+	bool literal = false;
+
+	bool entering = (ev_type == CMARK_EVENT_ENTER);
+
+	if (entering) {
+		indent(state);
+		cmark_strbuf_printf(xml, "<%s", cmark_node_type_string(node));
+
+		if (node->start_line != 0) {
+			cmark_strbuf_printf(xml, " sourcepos=\"%d:%d-%d\"",
+					    node->start_line,
+					    node->start_column,
+					    node->end_line);
+		}
+
+		literal = false;
+
+		switch (node->type) {
+		case CMARK_NODE_TEXT:
+		case CMARK_NODE_CODE:
+		case CMARK_NODE_HTML:
+		case CMARK_NODE_INLINE_HTML:
+			cmark_strbuf_puts(xml, ">");
+			escape_xml(xml, node->as.literal.data,
+				   node->as.literal.len);
+			cmark_strbuf_puts(xml, "</");
+			cmark_strbuf_puts(xml, cmark_node_type_string(node));
+			literal = true;
+			break;
+		case CMARK_NODE_CODE_BLOCK:
+			if (node->as.code.info.len > 0) {
+				cmark_strbuf_puts(xml, " info=\"");
+				escape_xml(xml, node->as.code.info.data,
+					   node->as.code.info.len);
+				cmark_strbuf_putc(xml, '"');
+			}
+			cmark_strbuf_puts(xml, ">");
+			escape_xml(xml, node->as.code.literal.data,
+				   node->as.code.literal.len);
+			cmark_strbuf_puts(xml, "</");
+			cmark_strbuf_puts(xml, cmark_node_type_string(node));
+			literal = true;
+			break;
+		case CMARK_NODE_LINK:
+		case CMARK_NODE_IMAGE:
+			cmark_strbuf_puts(xml, " url=\"");
+			escape_xml(xml, node->as.link.url, -1);
+			cmark_strbuf_putc(xml, '"');
+			cmark_strbuf_puts(xml, " title=\"");
+			escape_xml(xml, node->as.link.title, -1);
+			cmark_strbuf_putc(xml, '"');
+			break;
+		default:
+			break;
+		}
+		if (node->first_child) {
+			state->indent += 2;
+		} else if (!literal) {
+			cmark_strbuf_puts(xml, " /");
+		}
+
+	} else {
+		if (node->first_child) {
+			state->indent -= 2;
+		}
+		indent(state);
+		cmark_strbuf_printf(xml, "</%s", cmark_node_type_string(node));
+	}
+
+	// TODO print attributes
+
+	cmark_strbuf_puts(xml, ">\n");
+
+	return 1;
+}
+
+char *cmark_render_xml(cmark_node *root)
+{
+	char *result;
+	cmark_strbuf xml = GH_BUF_INIT;
+	cmark_event_type ev_type;
+	cmark_node *cur;
+	struct render_state state = { &xml, 0 };
+	cmark_iter *iter = cmark_iter_new(root);
+
+	cmark_strbuf_puts(state.xml,
+			  "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n");
+	cmark_strbuf_puts(state.xml,
+			  "<!DOCTYPE CommonMark SYSTEM \"CommonMark.dtd\">\n");
+	while ((ev_type = cmark_iter_next(iter)) != CMARK_EVENT_DONE) {
+		cur = cmark_iter_get_node(iter);
+		S_render_node(cur, ev_type, &state);
+	}
+	result = (char *)cmark_strbuf_detach(&xml);
+
+	cmark_iter_free(iter);
+	cmark_strbuf_free(&xml);
+	return result;
+}