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From: spector@brillig.umd.edu (Lee Spector)
Newsgroups: comp.sys.mac.hypercard
Subject: Re: EvalExpr() callback in XCMDs
Message-ID: <25393@mimsy.umd.edu>
Date: 9 Jul 90 22:09:11 GMT
References: <1388taylorj@yvax.byu.edu>
Sender: news@mimsy.umd.edu
Reply-To: spector@brillig.umd.edu (Lee Spector)
Organization: U of Maryland, Dept. of Computer Science, Coll. Pk., MD 20742
Lines: 27

In article <1388taylorj@yvax.byu.edu> taylorj@yvax.byu.edu writes:
>
>... X-commands have error results returned to them, as
>opposed to an error dialog popping up.  This is so that the X-command can
>handle the error appropriately without bothering the user.  

Hmm... This should allow the creation of a WithoutError XCMD which would
evaluate an arbitrary line of hypertalk (WITHIN HC) without the possibility 
of an error  reaching the user.  Any returned error message could be stuffed 
into a global variable or something.   This would allow something like:
  
  ...
  WithoutError "myCommand (myfunction1 (foo))"
  if the result contains "Error" then  -- or however you test the result
    put "something went wrong but I don't care"
  end if
  ...

I imagine that this could be useful in a number of situations.  For example
it would be handy when consing together code for "do" on the fly; it would 
be nice to be able to allow gibberish through once in a while and to just 
have it do nothing...  Anyway, has anyone done this?  If so, can I have a 
copy?   

  Thanks!

 -Lee (spector@cs.umd.edu)