Help understanding QLexers

[Andrea]

On 23/01/2021 11:54, kristof.mulier at telenet.be wrote:
> Hi Andrea,
> Did you have a look at the QScintilla (unofficial) documentation page?
> Here is the page about lexers:
> https://qscintilla.com/#syntax_highlighting
> 
> And here about your specific question:
> https://qscintilla.com/#syntax_highlighting/subclass_qscilexercustom/all_about_styles
> 
> Hope it helps.
> 

It helps to a degree.
I seem to understand that LexerCustom is very powerful and requires subclasses to
1) define all the styles they need
2) apply them in styleText() when they are needed

and there is no leak of the definition of is a number or a comment outside this class.

But it leaves open a few questions
1) why are the other lexers not inheriting form custom, what do they do which is different?
2) all other lexers seems to offer much more usable interface based on keywords (sets of keywords)

And in a lot of cases, this is all it is needed. Add a couple of options to define what is a string 
(" vs '), what is a comment and people do not need to think how to implement styleText().

So, I still think the interface is upside down.
Custom should have been the base class.
Then a keyword-based implementation (from which all existing lexers derive from)
And if one needs a really special lexer, then she can derive and do something completely different.

But I think I am very confused about how to read the documentation.

This is what I need to understand.
https://www.scintilla.org/ScintillaDoc.html#SCI_SETKEYWORDS

Thanks