From: drm1@vrdxhq.UUCP (Donn Milton)
Subject: Re: misleading article on type checking procedure parameters
Date: Mon, 9-Jun-86 20:04:48 EDT [thread overview]
Date: Mon Jun 9 20:04:48 1986
Message-ID: <8606100004.AA26151@vrdxhq.uucp> (raw)
The key point is that parameters need to be fully specified, to
to an arbitrary (and not necessarily finite) degree of nesting, in
order to permit full type-checking. This requires some sort of
recursive type definition for procedures.
Sherman claims that he has written a compiler that performs full type-checking,
presumably in the absence of fully specified procedure parameters.
I would be very interested in hearing more about such a compiler,
since so far Langmaack has convinced me it is impossible.
I do not have the reference to Clarke's result, but from the description
it is does not conflict with Langmaack, as long as
Clarke was referring to "fully-specified procedure parameters."
I also do not understand the point of the program that Sherman
presented, for which he states "you give a compiler that can tell
me if this program generates a runtime (type check) error, and I'll solve the
halting problem." The crux of strong type-checking is that it
is done at compile-time and not at run-time. The program should generate
a compile-time error -- it is irrelevant whether the particular portion
of the program that contains the error would be executed at run-time.
Donn Milton
next reply other threads:[~1986-06-10 0:04 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
1986-06-10 0:04 Donn Milton [this message]
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1986-06-09 18:20 misleading article on type checking procedure parameters Mark Steven Sherman
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