Gedit highlight (gtksourceview): how to highlight a block inside [curly] braces with a color

Question

I need to highlight every whole block of code that is inside curly braces, so I created a rule:

<context id="action-body" style-ref="action-body" extend-parent="true">
   <start>{</start>
   <end>}</end>
   <include>
      <context ref="builtin-vars" />
      <context ref="keywords" />
   </include>
</context>

It highlights code, keywords and vars inside correctly, but it of course stops if there is another closing curly bracket inside. I know that it is not trivial for regular expressions to check level of recursion, but may be gtkSourceView syntax has something special for cases like these?

It is a serious thing, because a language (PegJS, in fact) I am making highlighting for can contain JavaScript code only inside curly braces, not outside. And I want to highlight them with one color exluding :)

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Related:

• Regex to get string between curly braces "{I want what's between the curly braces}"
• How can I extract a string between matching braces in Perl?

Answer 1

This way (from) highlights ok (gedit goes a little slow when cursor in braces) when such syntax is used on a single line, but not for multi-line:

<context id="action-body" style-ref="action-body">
   <match>(\{(?:[^{}]*|(?0))*\})</match>
   <!-- <include>
      <context ref="builtin-vars"/>
      <context ref="keywords"/>
   </include> -->
</context>

(and it do not allows me to use included contexts, but the spec says I can :( )