Myujth

I am attempting to write a music related package where the user can enter chord names, that will be nicely printed:

% this prints out the C chord
somecommandC

However, a chord names can have sharps and flats and I want the UI to be as simple as possible. Basically, avoid the need for the user to have to escape the # character, so he can write just this:

somecommandC#

instead of this:

somecommandC#

In this answer, I read that this can be done with:

catcode`#=12

So this, indeed, works:

documentclassarticle
newcommandmycommand[1]

 chord=#1
 
catcode`#=12 
begindocument
mycommandG#
enddocument

And prints "chord=G#".

However, I am unable to make that trick work in the real situation, because all of this is actually embedded into a Tikz environment:

documentclassarticle
usepackagetikz

newenvironmentmyenv

 newcommandmycommand[1]
 
 draw(0,0) node chord=##1;
 
 begintikzpicture


 endtikzpicture
 

catcode`#=12

begindocument
beginmyenv
mycommandG#
endmyenv
enddocument

This MCVE produces lots of errors that I cannot understand:

ABD: EveryShipout initializing macros
(/usr/local/texlive/2017/texmf-dist/tex/context/base/mkii/supp-pdf.mkii
[Loading MPS to PDF converter (version 2006.09.02).]
! Use of @@mptopdf@@newabove doesn't match its definition.
l.136 @@mptopdf@@newabove csname n
 ewcountendcsname scratchcounter
If you say, e.g., `defa1...', then you must always
put `1' after `a', since control sequence names are
made up of letters only. The macro here has not been
followed by the required stuff, so I'm ignoring it.

! Extra endcsname.
l.136 ...opdf@@newabove csname newcountendcsname
...

Questions:

• Can this be fixed in some way? How?


• Or am I going the wrong way? Is there another path to achieve this goal?

Delay the setting:

documentclassarticle
usepackagetikz

newenvironmentmyenv
 %
 newcommandmycommand[1]
 %
 draw(0,0) node chord=##1;
 %
 begintikzpicture
 
 %
 endtikzpicture%
 

AtBeginDocumentcatcode`#=12 

begindocument
beginmyenv
mycommandG#
endmyenv
enddocument

It's a bad idea nonetheless. Use G# and your life will be better.

documentclassarticle
usepackagetikz

 newcommandmycommand[1]
 
 draw(0,0) node chord=#1;
 

newenvironmentmyenv

 catcode`#=12
 begintikzpicture


 endtikzpicture




begindocument
beginmyenv
mycommandG#
endmyenv
enddocument