13 Jan
2019
13 Jan
'19
9:41 a.m.
One connection Knuth had to Unix was inventing LALR parsing, the basic
algorithm used in Yacc. I added some things (notably, the precedence
mechanism) and had to do a lot of engineering to be able to handle
large grammars (e.g. F77) on a PDP-11. But the underlying algorithm
(taught to my be Al Aho) was all Knuth.
I seem to recall also that a lot of us at that time were underwhelmed
by The Art of Computer Programming, especially the use of MIX.
Perhaps it just meant that Knuth was doing things bottom up, while we
were doing amazing things in small spaces with B and C.
Steve
----- Original Message -----
From: arnold(a)skeeve.com
To:<ecashin@noserose.net>, <dave(a)horsfall.org>
Cc:<tuhs@tuhs.org>
Sent:Thu, 10 Jan 2019 00:39:28 -0700
Subject:Re: [TUHS] Knuth and Unix
Ed Cashin <ecashin(a)noserose.net> wrote:
Knuth is great, and I too am interested to know about
his influence
on
UNIX, but Hoare is credited with the quicksort
algorithm by the
authorities I've encountered.
Hoare did indeed invent it. He describes the history, IIRC, in his
Turing Award
lecture. (I know I read it, written by him, somewhere.)
Arnold