Re: ly:add-option behaviour

[Urs Liska]

Am 08.08.2016 um 15:53 schrieb David Kastrup:
> Urs Liska <address@hidden> writes:
>
>> I'm wondering about the behaviour of ly:add-option
>>
>> If I have the following file:
>>
>> \version "2.19.47"
>>
>> #(ly:add-option 'humdrum-file #f "Set to the file name of a Humdrum file")
>>
>> #(display (ly:get-option 'humdrum-file))
>>
>> and invoke LilyPond with the command line option -dmy-option=my-value
>>
>> The display is #f or whatever I set as default value in ly:add-option.
>>
>> If I comment out the ly:add-option line I get the correct value
>> displayed but also a warning "no such internal option: my-option".
>>
>> I thought I could use that line to suppress the warning and preset the
>> option with a default value that it will have when the option isn't
>> passed on the command line. But I have the impression that ly:add-option
>> *overwrites* any value passed through the command line.
>>
>> What am I missing?
> ly:add-option takes effect too late to be of any use except in
> LilyPond's initialization phase.
>

That means ly:add-option is of no use in user files?