Re: [NOISE] Curly braces [was Re: Curl]

[Guy Steele - Sun Microsystems Labs <address@hidden>]

   From: Michael Vanier <mvanier@bbb.caltech.edu>
   To: dlw@exceloncorp.com
   Cc: ll1-discuss@ai.mit.edu
   Subject: Re: [NOISE] Curly braces [was Re: Curl]
   Date: Thu, 29 Nov 2001 23:03:20 -0800 (PST)
   
   
   > Date: Fri, 30 Nov 2001 01:58:46 -0500 (EST)
   > From: Dan Weinreb <dlw@exceloncorp.com>
   [snip]
   > I don't know if it got much use.  I and the friends with whom I worked
   > most closely at the time certainly have earnestly argued that
   > 
   >  (> (/ (+ (- b) (sqrt (- (* b b) (* 4 a c)))) (* 2 a) 0)
   > 
   
   Don't you mean:
   
   (> (/ (+ (- b) (sqrt (- (* b b) (* 4 a c)))) (* 2 a)) 0)
   
   ?  I think that unmakes your point.
   
Oh, c'mon; it's no worse than when people write

  (-b + sqrt(b*b-4*a*c)) / 2*a

when it should have been

  (-b + sqrt(b*b-4*a*c)) / (2*a)

And a Lisp reader would have caught Dan's error,
and a Lisp compiler would have caught the error if he had written

  (> (/ (+ (- b) (sqrt (- (* b b) (* 4 a c)))) (* 2 a) 0))

but no compiler would catch the one I have suggested.

--Guy