macros / code construction (and assignment)

Rainer Blome rainer at
Thu Aug 31 15:28:01 UTC 1995

Brook wrote:

> You can get 90% of 'if bool then else':
> if: bool Then: thenClause Else: elseClause = 
>    ( bool if: thenClause False: elseClause ).

Oh, OK.  In this case, a macro would indeed be an efficiency hack.  Because
using a message would give up locality there.  Where is the `if:Then:Else:'
slot?  In globalBehavior, I guess.  And that slot takes time to find.  If
its content is a normal method, it will be evaluated over and over again.
Maybe the compiler can optimize that away, but I don't think so.

If it instead explicitly transforms the code, and does that only once, the
boolean will again get to handle the message directly.  This would have to
happen at `initialization time / block/method creation time'.  But then a
syntactic context is necessary. *frown*  Or the code could be modified when
it is first evaluated.  *big frown*

Gee, I know too little in this area, I give in (for now ;-).  Have to read
think some more there, especially about BETA and syntactic stuff in Scheme.

Your idea to reverse the capitalization is nice, I like it.

> Figure out some inference rule to get rid of the colons, then figure
> out another one to allow white space in names and you're really
> cooking.... 

The result looks tempting, but rules like that can and will _really_ bite
you is my guess. :-(


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