Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site ecsvax.UUCP Path: utzoo!watmath!clyde!burl!ulysses!allegra!mit-eddie!genrad!decvax!mcnc!ecsvax!dgary From: dgary@ecsvax.UUCP (D Gary Grady) Newsgroups: net.lang.forth Subject: Re: redefine "+" ?? Message-ID: <689@ecsvax.UUCP> Date: Mon, 11-Feb-85 13:59:26 EST Article-I.D.: ecsvax.689 Posted: Mon Feb 11 13:59:26 1985 Date-Received: Thu, 14-Feb-85 01:43:47 EST References: <2480@tekig.UUCP>, <375@harvard.ARPA> Organization: Duke U Comp Ctr Lines: 22 > Do any of you FORTH experts out there know the answer to this: > How do you redefine the "+" function (or any other operator) such that > entering "2 + 2" yields "4" instead of typing "2 2 +". Is this > impossible in FORTH ? You can do something like this: : + 32 WORD NUMBER + ; This defines plus to be a word that reads in the following word, converts it to a number on the stack, then adds that to the number previously put there. This is almost identical to a similar word defined on page 277 of Brodie's _Starting Forth_. A similar idea is used with almost all text-oriented operations in Forth. Although Forth uses postfix notation for numbers, for text it (of practical necessity) reverts to prefix or infix. -- D Gary Grady Duke U Comp Center, Durham, NC 27706 (919) 684-3695 USENET: {seismo,decvax,ihnp4,akgua,etc.}!mcnc!ecsvax!dgary