Re: Add option to indicate frets by letters in tablature (issue164063)

[Trevor Daniels]

Hi Carl

Thanks for taking a look at this.

You wrote Sunday, December 06, 2009 3:23 PM>
> http://codereview.appspot.com/164063/diff/2001/3008
> File scm/translation-functions.scm (right):
>
> http://codereview.appspot.com/164063/diff/2001/3008#newcode393
> scm/translation-functions.scm:393: (define-public
> (fret-letter-tablature-format str context event)
> The change from string to str is contrary to the desired goal in
> LilyPond programming.
>
> The goal is to have all variable names be english words, rather 
> than
> abbreviations of english words.
>
> There is lots of legacy code where that is not true, but we should 
> not
> be writing new code like this.

I changed it because "string" is a keyword in Scheme.
It is even used as such in the same few lines of code.
Although "string" can be used as a variable name I don't
think it should be - it seems bad practice to overload
keywords in this way.

I fully agree with your point in general, but we need
to think of a variable name other than "string" for the
string on an instrument.  I tried, and failed :(, hence
str.

> http://codereview.appspot.com/164063/diff/2001/3008#newcode399
> scm/translation-functions.scm:399: (make-vcenter-markup
> If length of 'fretLetterExceptions is greater than zero, I think 
> we
> ought to throw a warning if fret is higher than the length of
> 'fretLetterExceptions so that the user will have an idea of why 
> things
> didn't work the way they wanted it to.

Hhm, I'm not so sure about this.  I had envisaged changing
only the c to r, leaving all letters beyond c to default.
As this would be the norm I don't think a warning is desirable,
but I'm willing to be convinced otherwise.  Actually, for most
ancient instruments only i or j, not both, is used, so maybe the
length of fretLetterExceptions would be somewhat greater than
3 normally, making a warning more appropriate.  Although if i
not j is a general rule, maybe that should be built in to the
default, then we'd be back to needing just the change from c to r.
Maybe a question on -user is needed on this point.

Trevor