Feature request

[Gaston Gloesener]

Hi,

Here is my feature proposal.

A lot of parsers generated use a whole lot of key words resulting in
something like:

%%
keyword  { return KEYWORD; }

Therefor I would suggest a set of macors like:

%key(KeyWord,...)               // Keyword
%lkey(KeyWord,...)      // Lowercase keyword
%ukey(KeyWord,...)      // Uppercase keyword
%olkey(KeyWord,...)     // optional lowercase keyword
%oukey(KeyWord,...)     // optional upercase keyword

Any of these keywords without arguments (example%olkey) sets the default
mode for the %key(KeyWord) macro. For example %olkey makes all subsequent
%key(KeyWord) act as if it was a %olkey. %key resets the behavior to
default.

In default mode the above lines would have generated the following (in the
order of the above lines):
KeyWord { return KEYWORD; }
keyword { return KEYWORD; }
KEYWORD { return KEYWORD; }
[Kk]ey[Ww]ord   { return KEYWORD; }
K[eE][ey]W[Oo][rR][dD]  { return KEYWORD; }

Additional related features:

Any action placed after the %key (with the exception of the empty ';'
action) should be included in the action statement before the automatic
generated return statement. An ection placed after an 'empty' macro
(%key,%lkey... without arguments) shoudl additionally to set the default
behavior of the %key macro also set its action as being the default action
for any of the %*key macros

%keyprefix PREFIX_      // Uses the given prefic (here PREFIX_) in front of any
keyword as token name in the return statment.
Example:

%keyprefix PREFIX_
%olkey  { BEGIN CONTEXT;}       // Sets default behavior of %key and the defaul
action fo all subsequent %*key macros
%key(KeyWord)    { CallAFunction() ; }

generates:
[Kk]ey[Ww]ord   { { BEGIN CONTEXT;}  { CallAFunction(); } return
PREFIX_KEYWORD;

Note that the default action is placed prior to the "local" action and
finaly the default return

What do you think about this draft idea ?

Regards,
Gaston