Lexer and optional arguments

[Daniel]

On 2022-04-18 19:46, Jean-Marc Lasgouttes wrote:
> Le 18/03/2022 à 18:45, Daniel a écrit :
>> Is it possible to have optional arguments read with Lexer? I imagine 
>> something like:
>>
>> Command <Parameter1> [<Parameter2>]
>>
>> So Parameter1 is necessary but Parameter2 is optional. The Lexer would 
>> only look on the same line for an optional parameter.
> 
> Going back to old mails...

Me too... Unfortunately, I still find the lexer stuff hard to understand.

> What is possible is to read one line with eatLine() and then parse it, 
> possibly with the lexer itself.

Maybe someone can give me a hint on how to create a lexer from a string 
that I get via eatLine()?

> Or do something like in Layout::readAlignPossible.

So, could I alternatively just use lex.next() and still don't eat too 
many commands because it would be somehow reset once I use 
lex.popTable(), or what would be the idea?

Background:

I am back to getting the DynamicMenuButton to work with classic menus 
rather than having to hard code every menu in a cumbersome and 
non-customizable way.

It works, but I would like to combine two different button styles:

(1) a simple menu when one clicks on a button (as with Custom text styles)

(2) a function on the button itself and a menu to the side (as with Paste).

So, I thought about a function like this:

DynamicMenuButton <menu> <label> [<function>]

where the last argument is optional.

/Daniel