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From: henry@utzoo.UUCP (Henry Spencer)
Newsgroups: net.lang
Subject: Re: Lexical analyzers and parsers
Message-ID: <3841@utzoo.UUCP>
Date: Sat, 12-May-84 01:07:05 EDT
Article-I.D.: utzoo.3841
Posted: Sat May 12 01:07:05 1984
Date-Received: Sat, 12-May-84 01:07:05 EDT
References: <1632@tekig1.UUCP>
Organization: U of Toronto Zoology
Lines: 30

Don Taylor asks, in part:

   With the fixed format decisions that went into FORTRAN, seemingly making
      an easier job, what drove the design of the language?  We have to 
      recognize that at the time, there was absolutely no theory to support
      what was being done, I seem to remember somewhere that the very first
      FORTRAN, a fairly simple language by undergrad compiler class standards,
      took 18 man years to complete.

According to Backus's paper in the symposium a few years ago on the
history of programming languages, Fortran was barely "designed" at all.
The idea was to make a programming language based on mathematical equations;
everything else was kind of an ad-hoc afterthought.  They just sort of made
it up as they went along.

He also explained, in detail, why the first Fortran compiler took so long.
Some of it was lack of previous work to draw on, but a lot of it was the
required quality of object code.  There was great fear that Fortran would
not be taken seriously unless the compiler produced *very* good code.  Most
"programming languages" of the time were interpretive, and everybody knew
that they were useless for serious number-crunching.  As a result, the
first real compiler also had to be the first super-optimizing compiler.
The amazing thing was that they succeeded!  According to Backus, the
production compiler could produce (correct) code whose derivation from
the source could be understood only with the assistance of three or four
members of the compiler team.  The very first Fortran compiler produced
better code than most of its successors.
-- 
				Henry Spencer @ U of Toronto Zoology
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