Hi,
We're encountering a problem with the APEXLang export through SQLcl (tested with both 26.1 and 26.2), but also from the APEX builder (26.1 patch 2).
We have our own plugin that has an attribute where the value is a single opening square bracket. When we export the app as APEXLang and run SQLcl apex validate or try to import it, it returns the following error on this attribute:
Property: mentionMarker, does not support Arrays
Apparently it sees the value as the start of an array instead of a string.
The workaround is to replace [ in the exported .apx file by "[", but we would have to do that on every export for multiple APEX pages.
I tested some more and found that the problem also occurs on non-plugin attributes.
On oracleapex.com I created a new app and only added a page item with value [ in the label attribute to the home page. This doesn't throw the error, because there are no other square brackets on the page and the APEXLang parser apparently has a way to deal with that. However, if there is another attribute that is an array, for example when adding some template options to that same page item, it DOES throw an error when validating.
It seems to me that this is a bug in the parser.