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From: John Gerard Malecki <johnm@vlibs.com>
To: caml-list@pauillac.inria.fr
Subject: Label Names Space - philosophy or implementation?
Date: Mon, 22 Jul 1996 17:40:16 -0700 (PDT)	[thread overview]
Message-ID: <199607230040.RAA11401@owl.vlibs.com> (raw)


A co-worker has (vehemently) pointed out to me that record label names
cannot be shared.  For example, the following fails

	type foo = { name : string; x : int }
	let    a = { name = "foo";  x = 1 }

	type bar = { name : string; y : float }
	let    b = { name = "bar";  y = 9. }

	let   a' = { name = "foo";  x = 2 }

With an error message on the last line that "The label x belongs to
the type foo but is here mixed with labels of type bar".  This annoys
my co-worker to no end.  He would like many of his records to have a
field with a standardized label.  This makes it easier for him to
write printers for his data-structure.  Does anyone have a
recommendation to make to him?

Until this morning I would have guessed that the type of a record was
not resolved until all of the labels were examined.  As I re-read the
caml-light and ocaml manuals I see that this is not true.

Are there good reasons for this "restriction"?  I can see how this
this might be considered a good software practice.  Maybe, due to
pattern matching, it is not possible to have shared labels.

Any comments?





             reply	other threads:[~1996-07-23  9:57 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
1996-07-23  0:40 John Gerard Malecki [this message]
1996-07-23 11:36 ` Pierre Weis
1996-07-24  7:37 ` pbrisset
1996-07-24  9:40 ` Xavier Leroy
1996-07-23 18:13 Andrew Conway

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