Article View: comp.lang.functional
Article #411Re: What is strong typing? (Was: I like strong typing)
From: Nick Rothwell
Date: Wed, 01 Aug 1990 10:55
Date: Wed, 01 Aug 1990 10:55
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1576 bytes
In article <3263@stl.stc.co.uk>, tom@stl.stc.co.uk (Tom Thomson) writes:
> Why should type checking be restricted to compile time?
> It is perfectly possible to have strong typing which is done wholely
> at run-time (any interpreter is going to behave like that).
No, you can have interpreters which don't do typechecking at all. Our
ML system just interprets a form of untyped language calculus. Why is
typechecking an issue connected to interpretation?
> Currently most systems do some type checking at run time: what is a
> divide-by-zero eroor trap except a type failure indication from the hardware?
0 is an integer, just like 17 is. Milner-style typechecking is structural,
so it knows about, say, integers, but not about positive integers, primes,
and non-structural entities of this kind.
--
Nick Rothwell, Laboratory for Foundations of Computer Science, Edinburgh.
nick@lfcs.ed.ac.uk <Atlantic Ocean>!mcsun!ukc!lfcs!nick
~ ~~ ~~ ~~ ~~ Hey, son, get that DeLorean off the track! And ~~ ~~ ~~ ~~ ~
what have you done with all my lovely harpsichords?
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Path: arc1-ca.pugleaf.net!utzoo!attcan!uunet!mcsun!ukc!edcastle!lismore!nick From: nick@lfcs.cs.edinburgh.ac.uk (Nick Rothwell) Newsgroups: comp.lang.functional Subject: Re: What is strong typing? (Was: I like strong typing) Message-ID: <5448@castle.ed.ac.uk> Date: 1 Aug 90 10:55:58 GMT References: <4387@uqcspe.cs.uq.oz.au> <1689@opal.tubopal.UUCP> <4424@uqcspe.cs.uq.oz.au> <3263@stl.stc.co.uk> Reply-To: nick@lfcs.ed.ac.uk (Nick Rothwell) Organization: Wavetables 'R' Us Lines: 21