Re: Comments on \defineshortcut

[Hans Hagen <pragma@wxs.nl>]

At 01:16 PM 2/1/01 +0100, Giuseppe Bilotta wrote:
>Hello, I'm playing with shortcuts now, and I found some limitations on the
>current implementation.
>
>It's impossible to re-define shortcuts other than <>; the reason is that,
once I
>issue
>
>\defineshortcut [()][a][style=\overstrike]
>
>I cannot issue
>
>\defineshortcut [()][b][style=\underline]
>
>later because an "undefined control sequence" error is issued.

\def\dodefineshortcut[#1][#2][#3]%
  {\ifthirdargument
     \ConvertConstantAfter\doifelse{#1}{}
       {\dododefineshortcut[<>][#2][#3]}
       {\dododefineshortcut[#1][#2][#3]}%
   \else\ifsecondargument
     \dododefineshortcut[<>][#1][#2]%
   \else
     \dododefineshortcut[<>][][#1]%
   \fi\fi}

\defineshortcut [()][a][commando=\overbar]  test (a:bc) test
\defineshortcut [()][b][commando=\underbar] test (b:abc) test

>Second problem: ligs fail in some cases (if I \defineshortcut
>[--][o][style\overstrike] then the following lines misses a few beats:
>
>it seems -o:to work- well--does it?---really?

see it this way: in --- the first - picks up everything uuntil the next -
so the third - triggers a new - which cannot find its matching - 

>Third problem: math fails too:
>>
>$(a+b)/(a-c-d)_{a+b}$
>with -- and ++ defined as shortcuts fail (not on parenthesis, if I make those
>active too; depends on the fact that parenthesis are delimiters in math
mode?)

Hm, this works ok here, unless of course you redefine + a few times since
then the last meaning is used. 

\defineshortcut[++]  saves the old meaning which is + 
\defineshortcut[++]  saves th eole meaning which is shortcut 

and in math mode the second one is used which means that the first shortcut
is invokes.  

>(possibily this depends on shortcuts not being nestable); the latter is maybe
>more important.

not nestable indeed since they use delimited arguments. 

Beware: it's a dangerous mechanism anyway, esp when you load some module
that expects + to be +, so: use with care. 

Hans

PS. Actually i implemented shortcuts as a kind of joke. 
-------------------------------------------------------------------------
                                  Hans Hagen | PRAGMA ADE | pragma@wxs.nl
                      Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
 tel: +31 (0)38 477 53 69 | fax: +31 (0)38 477 53 74 | www.pragma-ade.com
-------------------------------------------------------------------------