Re: fret-diagram and barré with another finger on the same string

[Carl Sorensen]

On 3/13/19, 3:00 AM, "David Kastrup" <address@hidden> wrote:

    Carl Sorensen <address@hidden> writes:
    
    > On 3/12/19, 6:42 AM, "Federico Bruni" <address@hidden> wrote:
    >       %\fret-diagram-terse "x;o;o;5-1-(;5-1;7-3-);" % this returns "Wrong 
    >     type argument in position 1"
    >     }
    >
    > In order to have two indications on the same string (the end of the barre 
plus another fret) you will need to use either the fret-diagram or the 
fret-diagram-verbose format.  fret-diagram-terse only handles one indication 
per string.
    
    Is that a restriction inherent in the format or in the code?  The error
    message (if you want to call it that) seems less than helpful.  Like
    when you are in a foreign country and ask your table neighbor to pass
    the salt and they commit ritual suicide.  Doesn't inspire confidence.
    
I think the limitation is inherent in the format.  The markup argument in 
question says the following:

Mute string 6.
Have string 5 open.
Have string 4 open.
Start a barre on string 3 at the fifth fret with the first finger.
Have the first finger press string 2 at the fifth fret.
Have the 3rd finger press string 1 at the seventh fret and end a barre there.

The error message comes from the inability to end a barre on the 7th fret since 
there was never one started.

I agree that the error message is pretty abysmal; there is no error checking in 
the fret-diagram-terse procedure, so you get whatever results from trying 
inappropriate things.

I think there are two action items that result from this report.  One is to 
make clear in the documentation that only a single fret can be affected per 
string in a fret-diagram-terse markup.  Another is to at least put some 
rudimentary error checking in fret-diagram-terse.  I'll look into both.

Thanks,

Carl