Implement and expose a source map.

Its generation is conditioned to the setting of the
OPT_SOURCEPOS flag.

Add cmark_parser_get_first_source_extent(parser).
Add cmark_source_extent_get_start(extent).
Add cmark_source_extent_get_stop(extent).
Add cmark_source_extent_get_next(extent).
Add cmark_source_extent_get_previous(extent).
Add cmark_source_extent_get_node(extent).
Add cmark_source_extent_get_type(extent.
Add cmark_source_extent_get_type_string(extent).

API change.

src/CMakeLists.txt

@@ -18,6 +18,7 @@ set(HEADERS
   houdini.h
   cmark_ctype.h
   render.h
+  source_map.h
   )
 set(LIBRARY_SOURCES
   cmark.c
@@ -40,6 +41,7 @@ set(LIBRARY_SOURCES
   houdini_html_e.c
   houdini_html_u.c
   cmark_ctype.c
+  source_map.c
   ${HEADERS}
   )
 

src/cmark.h

@@ -66,6 +66,21 @@ typedef enum {
   CMARK_NODE_LAST_INLINE = CMARK_NODE_IMAGE,
 } cmark_node_type;
 
+typedef enum {
+  CMARK_EXTENT_NONE,
+  CMARK_EXTENT_OPENER,
+  CMARK_EXTENT_CLOSER,
+  CMARK_EXTENT_BLANK,
+  CMARK_EXTENT_CONTENT,
+  CMARK_EXTENT_PUNCTUATION,
+  CMARK_EXTENT_LINK_DESTINATION,
+  CMARK_EXTENT_LINK_TITLE,
+  CMARK_EXTENT_LINK_LABEL,
+  CMARK_EXTENT_REFERENCE_DESTINATION,
+  CMARK_EXTENT_REFERENCE_LABEL,
+  CMARK_EXTENT_REFERENCE_TITLE,
+} cmark_extent_type;
+
 /* For backwards compatibility: */
 #define CMARK_NODE_HEADER CMARK_NODE_HEADING
 #define CMARK_NODE_HRULE CMARK_NODE_THEMATIC_BREAK
@@ -93,6 +108,7 @@ typedef enum {
 typedef struct cmark_node cmark_node;
 typedef struct cmark_parser cmark_parser;
 typedef struct cmark_iter cmark_iter;
+typedef struct cmark_source_extent cmark_source_extent;
 
 /**
  * ## Custom memory allocator support
@@ -504,6 +520,11 @@ void cmark_parser_feed(cmark_parser *parser, const char *buffer, size_t len);
 CMARK_EXPORT
 cmark_node *cmark_parser_finish(cmark_parser *parser);
 
+/** Return a pointer to the first extent of the parser's source map
+ */
+CMARK_EXPORT
+cmark_source_extent *cmark_parser_get_first_source_extent(cmark_parser *parser);
+
 /** Parse a CommonMark document in 'buffer' of length 'len'.
  * Returns a pointer to a tree of nodes.  The memory allocated for
  * the node tree should be released using 'cmark_node_free'
@@ -515,10 +536,44 @@ cmark_node *cmark_parse_document(const char *buffer, size_t len, int options);
 /** Parse a CommonMark document in file 'f', returning a pointer to
  * a tree of nodes.  The memory allocated for the node tree should be
  * released using 'cmark_node_free' when it is no longer needed.
+ * Returns NULL on error.
  */
 CMARK_EXPORT
 cmark_node *cmark_parse_file(FILE *f, int options);
 
+/**
+ * ## Source map API
+ */
+
+/* Return the index, in bytes, of the start of this extent */
+CMARK_EXPORT
+size_t cmark_source_extent_get_start(cmark_source_extent *extent);
+
+/* Return the index, in bytes, of the stop of this extent. This
+ * index is not included in the extent*/
+CMARK_EXPORT
+size_t cmark_source_extent_get_stop(cmark_source_extent *extent);
+
+/* Return the extent immediately following 'extent' */
+CMARK_EXPORT
+cmark_source_extent *cmark_source_extent_get_next(cmark_source_extent *extent);
+
+/* Return the extent immediately preceding 'extent' */
+CMARK_EXPORT
+cmark_source_extent *cmark_source_extent_get_previous(cmark_source_extent *extent);
+
+/* Return the node 'extent' maps to */
+CMARK_EXPORT
+cmark_node *cmark_source_extent_get_node(cmark_source_extent *extent);
+
+/* Return the type of 'extent' */
+CMARK_EXPORT
+cmark_extent_type cmark_source_extent_get_type(cmark_source_extent *extent);
+
+/* Return a string representation of 'extent' */
+CMARK_EXPORT
+const char *cmark_source_extent_get_type_string(cmark_source_extent *extent);
+
 /**
  * ## Rendering
  */