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From: gah4 <gah4@u.washington.edu>
Newsgroups: comp.compilers
Subject: ALGOLW parser
Date: Tue, 26 Jul 2022 23:31:33 -0700 (PDT)
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Xref: csiph.com comp.compilers:3135

I am looking at the source for the OS/360 ALGOLW compiler,
written by Wirth in about 1969.

There is a file which seems to be for a parser generator
that starts out like this:


<K REG> ::= <ID>
<T CELL ID> ::= <ID>
<PROC ID> ::= <ID>
<FUNC ID> ::= <ID>
<T CELL>  ::= <T CELL ID>
              <T CELL1>  )
              <T CELL2>  )
<T CELL1> ::= <T CELL2> <ARITH OP> <T NUMBER>
              <T CELL3> <T NUMBER>
<T CELL2> ::= <T CELL3> <K REG>
<T CELL3> ::= <T CELL ID>
<UNARY OP> ::= ABS
               NEG
               NEG ABS
<ARITH OP> ::= +
               -
               *
               /
               + +
               - -
<LOG OP>  ::=  AND
               OR
               XOR
<K REG ASS> ::= <K REG> := <T CELL>
                <K REG> := <T NUMBER>
                <K REG> := <STRING>
                <K REG> := <T CELL>


It looks like actual input to a program, and there is some output
from the processor, but I don't know what program it is.

This seems a little too early for lex/yacc.
[Algol W was written in PL360, a very nice little assembler with
Algol-like syntax. I'm pretty sure it used a hand-written parser and
what you have is part of the documentation. I also believe I saw a
thread somewhere saying the source code for both was lost, although
PL360 was used for other stuff and there may be later versions of it.
-John]