Path: utzoo!attcan!uunet!mcvax!ukc!etive!aipna!jeff
From: jeff@aipna.ed.ac.uk (Jeff Dalton)
Newsgroups: comp.lang.misc
Subject: Re: aGREeable features (was Re: Algol-68 down for the count)
Message-ID: <391@aipna.ed.ac.uk>
Date: 9 Dec 88 21:33:02 GMT
References: <406@ubbpc.UUCP> <3688@hubcap.UUCP> <2070@garth.UUCP> <3289@uoregon.uoregon.edu>
Reply-To: jeff@uk.ac.ed.aipna.UUCP (Jeff Dalton)
Organization: Dept. of AI, Edinburgh, UK
Lines: 13

In article <3289@uoregon.uoregon.edu> markv@drizzle.UUCP (Mark VandeWettering) writes:
>In article <2070@garth.UUCP> phipps@garth.UUCP (Clay Phipps) writes:

>	Call by name is very difficult to implement *in languages with
>	side effects*

It's pretty easy in some languages with side effects.  Scheme for
example.  And the Algol-60 "thunks" technique could be applied in
other languages.  (The idea is that each name parameter is represented
by procedures called "thunks".  There's one to get the value, and another
to set it.)

-- Jeff