API documentation is missing an explanation of CMARK_NODE_CUSTOM_BLOCK and CMARK_NODE_CUSTOM_INLINE

[arranstewart]

The API documentation for cmark (e.g. in the cmark.3 man page) does not explain the purpose or proper use of the CMARK_NODE_CUSTOM_BLOCK and CMARK_NODE_HTML_INLINE constants from the cmark_node_type enum. (Actually, it does not explain the purpose or use of any of the cmark_node_type constants; but all the others correspond fairly obviously to blocks or inlines in the CommonMark spec.)

I see that the changelog contains some description of them:

• [API change] Added CUSTOM_BLOCK and CUSTOM_INLINE node types. They are never generated by the parser, and do not correspond to CommonMark elements. They are designed to be inserted by filters that postprocess the AST. For example, a filter might convert specially marked code blocks to svg diagrams in HTML and tikz diagrams in LaTeX, passing these through to the renderer as a CUSTOM_BLOCK. These nodes can have children, but they also have literal text to be printed by the renderer "on enter" and "on exit." Added cmark_node_get_on_enter, cmark_node_set_on_enter, cmark_node_get_on_exit, cmark_node_set_on_exit to API.

But that information really should be in the API documentation, not in the changelog - without it, the API documentation cannot be understood. And because the changelog uses the abbreviation CUSTOM_BLOCK instead of spelling out CMARK_NODE_CUSTOM_BLOCK in full, searching for CMARK_NODE_CUSTOM_BLOCK in the repository will never bring up that changelog entry, making it difficult for developers to work out what it was intended to do.

If the man page is the only place that would need updating, then I'd be happy to create a PR to add the changelog information to the man page, if desired.

[jgm]

Agreed, this should be in the docs. Note that the man page is autogenerated from comments in the source (see the cmark.3 target in the Makefile). So you'd need to add comments to the source (cmark.h).

[arranstewart]

No worries - yes, I just now saw the make_man_page.py script as I was poking around. I'll let you know once I've got something. Cheers!