[Denemo-devel] embedded scheme in lilypond parser

[Richard Shann]

Next step in Denemo's new lilypond parser is embedded scheme:

We need to be careful not to perturb the lexer when swallowing the
scheme with scheme's read proc. Soft port is the way to go I think:

(define myport (make-soft-port ... lexer-getc ...
Then (read port) will get embedded scheme from the lilypond input being
lexed.

make-soft-port takes:

 1. procedure accepting one character for output #f
     2. procedure accepting a string for output --> lexer-ungetc (??? or
        do we need to take a string and call lexer-ungetc  with a char?)
     3. thunk for flushing output #f
     4. thunk for getting one character --> lexer-getc
     5. thunk for closing port (not by garbage collection) --> #f
     6. (if present and not #f) thunk for computing the number of
        characters that can be read from the port without blocking.
        --> #f
     7. 

This should work...

Richard