Re: scheme-function to provide value for \include

[Urs Liska]

Am 28.06.2016 um 11:05 schrieb David Kastrup:
> Urs Liska <address@hidden> writes:
>
>> Hi all,
>>
>> I am surprised that \include refuses to accept a string that isn't
>> passed literally but through a scheme-function:
>>
>> \version "2.19.43" givePath = #(define-scheme-function ()()   
>> "some/path/that/will/probably/not/be/found.ily") #(display (givePath))
>> \include \givePath
> \include is not a scheme function.  It switches input at a very low
> level.  \include is not even a reserved word and it never gets turned
> into a token.  It is a pattern of bytes causing an immediate reaction in
> the lexer.  That it accepts a #xxx or $xxx expression is hard-coded
> right in the lexer: it does not pass through the normal parser
> mechanisms for these constructs.
>
> Basically you are expecting something akin to the #include of the C
> preprocessor to accept calls of functions defined in C for specifying
> the file to include.
>

Thank you for the explanation.
Interestingly Harm provided a solution presumably working, but I have in
the meantime wrapped everything into a ly:parser-parse-string call.

Best
Urs