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Date: Sun, 10 Jun 2001 12:40:20 +0200 (CEST)
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From: Joerg Czeranski <jc@joerch.org>
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To: caml-list@inria.fr
Subject: Re: [Caml-list] Evaluation Order
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David McClain wrote:
> My mistake was writing
>
> let ans = process_stream() + process_tail()
>
> [...]
>
> The results of these two operations, integers, are arithmetically commutable
> under addition. But what isn't commutable is the order in which these
> operations occur. No current type checking in OCaml (or any other language
> with which I am familiar) could help catch this mistake.

A minor nit: commutativity isn't involved.
The problem would be the same for

  let y = f() / g()

and even

  let y = h (f()) (g())

Operators (and functions) just don't care in which order their operands
(parameters) are evaluated.

I really like Haskell's solution, but I've never used Haskell much.
The main reasons for this is OCaml's superior Unix binding
and it being much easier to build and install.

jörg
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