Added API documentation to src/cmark.h. Closes #224.

1 files changed, 109 insertions, 46 deletions

diff --git a/src/cmark.h b/src/cmark.h
index 85dffa4..9de1037 100644
--- a/src/cmark.h
+++ b/src/cmark.h
@@ -91,12 +91,14 @@ typedef enum {
  * ## Creating and Destroying Nodes
  */
 
-/**
+/** Creates a new node of type 'type'.  Note that the node may have
+ * other required properties, which it is the caller's responsibility
+ * to assign.
  */
 CMARK_EXPORT cmark_node*
 cmark_node_new(cmark_node_type type);
 
-/**
+/** Frees the memory allocated for a node.
  */
 CMARK_EXPORT void
 cmark_node_free(cmark_node *node);
@@ -105,52 +107,83 @@ cmark_node_free(cmark_node *node);
  * ## Tree Traversal
  */
 
+/** Returns the next node in the sequence after 'node', or NULL if
+ * there is none.
+ */
 CMARK_EXPORT cmark_node*
 cmark_node_next(cmark_node *node);
 
-/**
+/** Returns the previous node in the sequence after 'node', or NULL if
+ * there is none.
  */
 CMARK_EXPORT cmark_node*
 cmark_node_previous(cmark_node *node);
 
-/**
+/** Returns the parent of 'node', or NULL if there is none.
  */
 CMARK_EXPORT cmark_node*
 cmark_node_parent(cmark_node *node);
 
-/**
+/** Returns the first child of 'node', or NULL if 'node' has no children.
  */
 CMARK_EXPORT cmark_node*
 cmark_node_first_child(cmark_node *node);
 
-/**
+/** Returns the last child of 'node', or NULL if 'node' has no children.
  */
 CMARK_EXPORT cmark_node*
 cmark_node_last_child(cmark_node *node);
 
 /**
  * ## Iterator
+ *
+ * An iterator will walk through a tree of nodes, starting from a root
+ * node, returning one node at a time, together with information about
+ * whether the node is being entered or exited.  The iterator will
+ * first descend to a child node, if there is one.  When there is no
+ * child, the iterator will go to the next sibling.  When there is no
+ * next sibling, the iterator will return to the parent (but with
+ * a 'cmark_event_type' of `CMARK_EVENT_EXIT`).  The iterator will
+ * return `CMARK_EVENT_DONE` when it reaches the root node again.
+ * One natural application is an HTML renderer, where an `ENTER` event
+ * outputs an open tag and an `EXIT` event outputs a close tag.
+ * An iterator might also be used to transform an AST in some systematic
+ * way, for example, turning all level-3 headers into regular paragraphs.
+ *
+ *     void
+ *     usage_example(cmark_node *root) {
+ *         cmark_event_type ev_type;
+ *         cmark_iter *iter = cmark_iter_new(root);
+ *
+ *         while ((ev_type = cmark_iter_next(iter)) != CMARK_EVENT_DONE) {
+ *             cmark_node *cur = cmark_iter_get_node(iter);
+ *             // Do something with `cur` and `ev_type`
+ *         }
+ *
+ *         cmark_iter_free(iter);
+ *     }
  */
 
-/**
+/** Creates a new iterator starting at 'root'.
  */
 CMARK_EXPORT
 cmark_iter*
 cmark_iter_new(cmark_node *root);
 
-/**
+/** Frees the memory allocated for an iterator.
  */
 CMARK_EXPORT
 void
 cmark_iter_free(cmark_iter *iter);
 
-/**
+/** Returns the event type (`CMARK_EVENT_ENTER`, `CMARK_EVENT_EXIT`,
+ * or `CMARK_EVENT_DONE`) for the next node.
  */
 CMARK_EXPORT
 cmark_event_type
 cmark_iter_next(cmark_iter *iter);
 
-/**
+/** Returns the next node in the sequence described above.
  */
 CMARK_EXPORT
 cmark_node*
@@ -160,102 +193,108 @@ cmark_iter_get_node(cmark_iter *iter);
  * ## Accessors
  */
 
-/**
+/** Returns the type of 'node', or `CMARK_NODE_NONE` on error.
  */
 CMARK_EXPORT cmark_node_type
 cmark_node_get_type(cmark_node *node);
 
-/**
+/** Returns the string contents of 'node', or NULL if none.
  */
 CMARK_EXPORT const char*
 cmark_node_get_string_content(cmark_node *node);
 
-/**
+/** Sets the string contents of 'node'.  Returns 1 on success,
+ * 0 on failure.
  */
 CMARK_EXPORT int
 cmark_node_set_string_content(cmark_node *node, const char *content);
 
-/**
+/** Returns the header level of 'node', or 0 if 'node' is not a header.
  */
 CMARK_EXPORT int
 cmark_node_get_header_level(cmark_node *node);
 
-/**
+/** Sets the header level of 'node', returning 1 on success and 0 on error.
  */
 CMARK_EXPORT int
 cmark_node_set_header_level(cmark_node *node, int level);
 
-/**
+/** Returns the list type of 'node', or `CMARK_NO_LIST` if 'node'
+ * is not a list.
  */
 CMARK_EXPORT cmark_list_type
 cmark_node_get_list_type(cmark_node *node);
 
-/**
+/** Sets the list type of 'node', returning 1 on success and 0 on error.
  */
 CMARK_EXPORT int
 cmark_node_set_list_type(cmark_node *node, cmark_list_type type);
 
-/**
+/** Returns starting number of 'node', if it is an ordered list, otherwise 0.
  */
 CMARK_EXPORT int
 cmark_node_get_list_start(cmark_node *node);
 
-/**
+/** Sets starting number of 'node', if it is an ordered list. Returns 1
+ * on success, 0 on failure.
  */
 CMARK_EXPORT int
 cmark_node_set_list_start(cmark_node *node, int start);
 
-/**
+/** Returns 1 if 'node' is a tight list, 0 otherwise.
  */
 CMARK_EXPORT int
 cmark_node_get_list_tight(cmark_node *node);
 
-/**
+/** Sets the "tightness" of a list.  Returns 1 on success, 0 on failure.
  */
 CMARK_EXPORT int
 cmark_node_set_list_tight(cmark_node *node, int tight);
 
-/**
+/** Returns the info string from a fenced code block, or NULL if none.
  */
 CMARK_EXPORT const char*
 cmark_node_get_fence_info(cmark_node *node);
 
-/**
+/** Sets the info string in a fenced code block, returning 1 on
+ * success and 0 on failure.
  */
 CMARK_EXPORT int
 cmark_node_set_fence_info(cmark_node *node, const char *info);
 
-/**
+/** Gets the URL of a link or image 'node', or NULL if none.
  */
 CMARK_EXPORT const char*
 cmark_node_get_url(cmark_node *node);
 
-/**
+/** Sets the URL of a link or image 'node'. Returns 1 on success,
+ * 0 on failure.
  */
 CMARK_EXPORT int
 cmark_node_set_url(cmark_node *node, const char *url);
 
-/**
+/** Gets the title of a link or image 'node', or NULL if none.
  */
 CMARK_EXPORT const char*
 cmark_node_get_title(cmark_node *node);
 
-/**
+/** Sets the title of a link or image 'node'. Returns 1 on success,
+ * 0 on failure.
  */
 CMARK_EXPORT int
 cmark_node_set_title(cmark_node *node, const char *title);
 
-/**
+/** Returns the line on which 'node' begins.
  */
 CMARK_EXPORT int
 cmark_node_get_start_line(cmark_node *node);
 
-/**
+/** Returns the column at which 'node' begins.
  */
 CMARK_EXPORT int
 cmark_node_get_start_column(cmark_node *node);
 
-/**
+/** Returns the line on which 'node' ends.
  */
 CMARK_EXPORT int
 cmark_node_get_end_line(cmark_node *node);
@@ -264,61 +303,83 @@ cmark_node_get_end_line(cmark_node *node);
  * ## Tree Manipulation
  */
 
-/**
+/** Unlinks a 'node', removing it from the tree, but not freeing its
+ * memory.  (Use 'cmark_node_free' for that.)
  */
 CMARK_EXPORT void
 cmark_node_unlink(cmark_node *node);
 
-/**
+/** Inserts 'sibling' before 'node'.  Returns 1 on success, 0 on failure.
  */
 CMARK_EXPORT int
 cmark_node_insert_before(cmark_node *node, cmark_node *sibling);
 
-/**
+/** Inserts 'sibling' after 'node'. Returns 1 on success, 0 on failure.
  */
 CMARK_EXPORT int
 cmark_node_insert_after(cmark_node *node, cmark_node *sibling);
 
-/**
+/** Adds 'child' to the beginning of the children of 'node'.
+ * Returns 1 on success, 0 on failure.
  */
 CMARK_EXPORT int
 cmark_node_prepend_child(cmark_node *node, cmark_node *child);
 
-/**
+/** Adds 'child' to the end of the children of 'node'.
+ * Returns 1 on success, 0 on failure.
  */
 CMARK_EXPORT int
 cmark_node_append_child(cmark_node *node, cmark_node *child);
 
 /**
  * ## Parsing
+ *
+ * Simple interface:
+ *
+ *     cmark_node *document = cmark_parse_document("Hello *world*", 12);
+ *
+ * Streaming interface:
+ *
+ *     cmark_parser *parser = cmark_parser_new();
+ *     FILE *fp = fopen("myfile.md", "r");
+ *     while ((bytes = fread(buffer, 1, sizeof(buffer), fp)) > 0) {
+ *     	   cmark_parser_feed(parser, buffer, bytes);
+ *     	   if (bytes < sizeof(buffer)) {
+ *     	       break;
+ *     	   }
+ *     }
+ *     document = cmark_parser_finish(parser);
+ *     cmark_parser_free(parser);
  */
 
-/**
+/** Creates a new parser object.
  */
 CMARK_EXPORT
 cmark_parser *cmark_parser_new();
 
-/**
+/** Frees memory allocated for a parser object.
  */
 CMARK_EXPORT
 void cmark_parser_free(cmark_parser *parser);
 
-/**
+/** Feeds a string of length 'len' to 'parser'.
  */
 CMARK_EXPORT
-cmark_node *cmark_parser_finish(cmark_parser *parser);
+void cmark_parser_feed(cmark_parser *parser, const char *buffer, size_t len);
 
-/**
+/** Finish parsing and return a pointer to a tree of nodes.
  */
 CMARK_EXPORT
-void cmark_parser_feed(cmark_parser *parser, const char *buffer, size_t len);
+cmark_node *cmark_parser_finish(cmark_parser *parser);
 
-/**
+/** Parse a CommonMark document in 'buffer' of length 'len'.
+ * Returns a pointer to a tree of nodes.
  */
 CMARK_EXPORT
 cmark_node *cmark_parse_document(const char *buffer, size_t len);
 
-/**
+/** Parse a CommonMark document in file 'f', returning a pointer to
+ * a tree of nodes.
  */
 CMARK_EXPORT
 cmark_node *cmark_parse_file(FILE *f);
@@ -327,17 +388,19 @@ cmark_node *cmark_parse_file(FILE *f);
  * ## Rendering
  */
 
-/**
+/** Render a 'node' tree for debugging purposes, showing
+ * the hierachy of nodes and their types and contents.
  */
 CMARK_EXPORT
 char *cmark_render_ast(cmark_node *root);
 
-/**
+/** Render a 'node' tree as an HTML fragment.  It is up to the user
+ * to add an appropriate header and footer.
  */
 CMARK_EXPORT
 char *cmark_render_html(cmark_node *root);
 
-/**
+/** Render a 'node' tree as a groff man page, without the header.
  */
 CMARK_EXPORT
 char *cmark_render_man(cmark_node *root);