Exclamation marks are not parsed correctly

[obahareth]

Exclamation marks are not parsed correctly

[dumbbell]

Hi!

Sorry, I didn't notice your issue...

The !foobar notation is a tag handle in YAML: it tells the following tree (in your example the map with color, background and italic) should be interpreted in a specific way by the application, and not as a regular YAML node (i.e. a plain map in your example). Without this, the YAML constructor is unable to build the expected structure. That's why you're supposed to provide a module which is able to construct some kind of object from this map.

If you try your document with other online parsers, they will complain like yamerl:

• http://yaml-online-parser.appspot.com/
• https://codebeautify.org/yaml-validator/

That said, as YAML tags are quite complex, I don't pretend I totally understand how they work so I may be misinterpreting the specification. Thus I will add an option to ignore unrecognized tags and proceed as if it's a bare YAML document.

[dumbbell]

I just added the option. Here is an example with a subset of your document:

yamerl:decode_file("issue-26.yaml", [{ignore_unrecognized_tags, true}]).

[[{"IDE",
   [{"editor",
     [{"themes",
       [{"base16-zenburn",
         [{"built-in",
           [{"color","#dc8cc3"},
            {"background","#3f3f3f"},
            {"italic",false}]}]}]}]}]}]]

Is it good enough for your use case?

[obahareth]

Yeah that seems perfect, thanks @dumbbell!

[dumbbell]

Cool! Thanks :)

[lud]

Hi,

How do you provide tag handlers to the parser ?

Thank you

[dumbbell]

Hi @lud!

Tags are handled at the construction step, not the parsing step.

To implement your own node construction, I suggest you take a look at the Erlang anonymous function node construction:
https://github.com/yakaz/yamerl/blob/master/src/yamerl_node_erlang_fun.erl

You have to implement the same three exported functions:

• tags/0
• construct_token/3
• node_pres/1

To use this module, you need to configure it in the yamerl application. Here is an example with the Erlang function construction module:

yamerl_app:set_param(node_mods, [yamerl_node_erlang_fun]).

I should probably implement a behavior to ease that process.

[lud]

Perfect, thank you!