Path: utzoo!utgpu!jarvis.csri.toronto.edu!clyde.concordia.ca!uunet!willett!files
From: files@willett.UUCP (Mailed File Repository)
Newsgroups: comp.lang.forth
Subject: LANGUAGE OF ANS FORTH
Message-ID: <44.UUL1.3#5129@willett.UUCP>
Date: 20 Dec 89 06:01:04 GMT
Organization: Latest Link in ForthNet Chain
Lines: 31


 Date: 12-18-89 (23:34)              Number: 332 (Echo)
   To: IAN GREEN                     Refer#: 328
 From: SYSOP (ECFB/SHIFRIN)            Read: NO
 Subj: LANGUAGE OF ANS FORTH         Status: PUBLIC MESSAGE

 IG>    If you or someone has the complete BNF syntax for Forth (I am 
 IG>currently playing with L&Ps F83.COM). This I feel would go a long way 
 IG>towards clarifying the way the language works.

 Actually, Ian, the point I was trying to make is that Forth isn't
 usually willing to sit still long enough for someone to develop a
 detailed syntax. <grin>

 By that I mean that every Forth token is eligible for
 redefinition and may alter the syntax of itself and subsequent
 string.  For example, Forth programs may redefine or add IF or DO
 type control sructures, may redefine constants e.g.
         99 CONSTANT 5                     \ 5 now means 99!
 can even redefine existing functions in terms of themselves e.g.
         : DUP DUP ." DUPing " . CR DUP  ;  \ Trace uses of DUP
 and, in fact, can even redefine defining words like
         : CONSTANT CREATE ! DOES> @ DUP .S  ;
         : : : 1 #DEFS +! ;
 which redefines colon in terms of itself and adds a little
 counter.

 So, while you could get a BNF description of typical usage, it
 doesn't really define the language.
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  * QDeLuxe 1.10 #214s