Path: utzoo!utgpu!attcan!uunet!husc6!cs.utexas.edu!oakhill!steve
From: steve@oakhill.UUCP (steve)
Newsgroups: comp.lang.fortran
Subject: Re: Is DO WHILE difficult?
Summary: OOPS...
Message-ID: <1644@devsys.oakhill.UUCP>
Date: 7 Nov 88 20:19:17 GMT
References: <75326@sun.uucp> <75328@sun.uucp> <604@quintus.UUCP>
Organization: Motorola Inc. Austin, Tx
Lines: 34

<1643@devsys.oakhill.UUCP>

As usual I was far too hasty in replying.  My handlers wish me to clarify
something I just said that may have sounded wrong.

In article <1643@devsys.oakhill.UUCP>, steve@oakhill.UUCP (steve) writes:
> The second question - DO WHILE - is actually very easy.  The compiler
> we wrote contained the DO WHILE.  If you are doing a regular DO statement,
> DO WHILE is very easy, with very little overhead in the parser or
> in the sematic anaylsis (sematic analysis for DOWHILE and DO UNTIL is
                 actions           actions
> actually easier than that of DO).
> 

Also I'm sorry for rambling in my first part.  The idea I was trying to
get across was that FORTRAN lexical anaylsis is not pretty (The people
who write these routines are professionals.  Children are advised not
to try these same tricks at home. :-) ).  And that adding any extra syntax
to the lexical analysier just makes this harder and uglier.  The compiler
I just finished writing of course contained comments and blank line 
comments, but also was extended to have end of line comments, Debugging
statements (D in column 1) and Assembly statements (A in column one).
Needless to say, to get anything that ran decently fast, many ugly
tricks were performed.

                   enough from this mooncalf - Steven
----------------------------------------------------------------------------
These opinions aren't necessarily Motorola's or Remora's - but I'd like to
think we share some common views.
----------------------------------------------------------------------------
Steven R Weintraub                        cs.utexas.edu!oakhill!devsys!steve
Motorola Inc.  Austin, Texas 
(512) 440-3023 (office) (512) 453-6953 (home)
----------------------------------------------------------------------------