[Texmacs-dev] Some additions

[Nix N. Nix]

Hi!

Over the past 3 weeks, while you guys were busy, I was brooding over a
few things. Now, since you seem to be back in the swing of all things
TeXmacs, I'd like to see what you think of them.  For example:

I)
(kbd-map in-math? 
  ("C-_" (make-below))
  ("C-^" (make-above))
  ("M-A-~" (make-wide-under "~"))
  ("M-A-^" (make-wide-under "^"))
  ("M-A-B" (make-wide-under "<bar>"))
  ("M-A-V" (make-wide-under "<vect>"))
  ("M-A-C" (make-wide-under "<check>"))
  ("M-A-U" (make-wide-under "<breve>"))
  ("M-A-'" (make-wide-under "<acute>"))
  ("M-A-`" (make-wide-under "<grave>"))
  ("M-A-." (make-wide-under "<dot>"))
  ("M-A-\"" (make-wide-under "<ddot>")))

Would there be any major problems adding these keyboard bindings ?  For
the longest time there has been a lack of symmetry between make-wide
bindings and make-wide-under bindings.  I use both, so this would really
help. I currently have these in my my-init-texmacs.scm, but I don't see
why these couldn't be added to kbd-math.scm .  I don't know how to use
all those wildcards you have created for the various bindings (like
"math" and "math:greek" and "table" and the likes), so I don't really
know how to make a patch of it.

II)
(define (make-brackets left right)
  (if (selection-active-normal?)
    (begin (cut "primary") (make-large-left left) (paste "primary")
           (let* ((pos (tm-position-new)) (old (tm-position-get pos)))
             (make-large-right right)
             (tm-go-to old)
             (tm-position-delete pos)))
    (begin (make-large-left left)
           (let* ((pos (tm-position-new)) (old (tm-position-get pos)))
             (make-large-right right) 
             (tm-go-to old) 
             (tm-position-delete pos)))))

This is a hack.  It allows one to create matching brackets.  My impetus
for doing this is that when you write, say |a/b| by doing:

A-| A-f a <down> b A-|

followed by a conversion to LaTeX, the absolute value bars do not get
stretched.  Why ?  Because they do not form a matching \left| \right|
pair.  Instead, they are just stand-alone large delimiters.  My code
above would make sure that this never happens.  However, it /is/ a hack,
and here are the problems with it:

- Programmatically placing the cursor between the brackets only works if
  this code is executed when the cursor is inside a (concat ...), i.e.,

  M-F2 $ (make-brackets "(" ")") 
  
  doesn't place the cursor between the brackets, whereas

  M-F2 $ a (make-brackets "(" ")")
  
  does.

- Cutting to primary is a hack.  I was unable to find Scheme that deals 
  with manipulations of selections, other than the cut and paste 
  function.  I have talked to David about this (see our thread from 
  around 2003-03-23).  He said we could probably create some selection 
  accessors.

There is at least one person who was really happy to see this hack
(Álvaro Tejero Cantero).  See his message from 2003-03-21.

Also, (make-brackets ...) would be a perfect candidate for additional
useful keyboard bindings:

(kbd-map in-math? 
("C-(" (make-brackets "(" ")"))
("C-)" (make-brackets "(" ")"))
("C-[" (make-brackets "[" "]"))
("C-]" (make-brackets "[" "]"))
("C-{" (make-brackets "{" "}"))
("C-}" (make-brackets "{" "}"))
("C-<" (make-brackets "langle" "rangle"))
("C->" (make-brackets "langle" "rangle"))
("C-|" (make-brackets "|" "|"))
("C-:" (make-brackets "||" "||"))
("M-C->" (make-brackets "|" "rangle")) ;; "ket"
("M-C-<" (make-brackets "langle" "|")) ;; "bra"


I also have a question:
How can I override existing keyboard bindings ?  In earlier versions of
TeXmacs, I could define a keyboard binding in my-init-texmacs.scm that
was the same as the one for, say, (make-expand-arg "matrix"), and mine
would override it with some other function.  This no longer works.  Is
there something special I have to do in order to overwrite keyboard
bindings ?

Thank you for your attention.  I will go grab TeXmacs 1.0.1.9 now.