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Date: -- (:)
From: Michael Vanier <mvanier@c...>
Subject: Re: [Caml-list] syntax question
Adam,

I realize that this is how it works, but I don't understand why it should work this way. AFAIK 
elsewhere in ocaml "int * int" always refers to a tuple.  Similarly, if testme's Foo really took two 
int arguments I would expect to be able to create Foos as "Foo 1 2" instead of "Foo (1, 2)" which 
looks like Foo takes a single tuple argument, not two int arguments.  I don't see why "int * int" 
and "(int * int)" are different things.

Mike

Adam Granicz wrote:
> Hi Michael,
> 
> In the type definition
> 
>> # type testme = Foo of int * int;;
> 
> the constructor Foo takes *two* int arguments (thus, you can not 
> construct a testme value supplying only one argument), whereas in
> 
>> # type testme2 = Foo2 of (int * int);;
> 
> it takes *one* tuple argument.
> 
> Regards,
> Adam.
> 
> On Fri, 30 May 2008 00:23:40 +0200, Michael Vanier 
> <mvanier@cs.caltech.edu> wrote:
> 
>> Hi everyone,
>>
>> I got bitten by a simple syntax problem:
>>
>> # let a = (1, 2);;
>> val a : int * int = (1, 2)
>> # type testme = Foo of int * int;;
>> type testme = Foo of int * int
>> # Foo a;;
>> The constructor Foo expects 2 argument(s),
>> but is here applied to 1 argument(s)
>> # Foo (1, 2);;
>> - : testme = Foo (1, 2)
>> # type testme2 = Foo2 of (int * int);;
>> type testme2 = Foo2 of (int * int)
>> # Foo2 a;;
>> - : testme2 = Foo2 (1, 2)
>>
>> Why does the compiler treat int * int and (int * int) in type 
>> definitions so differently?  Is it to give clearer error messages in 
>> the typical case?
>>
>> Mike
>>
>>
>>
>>
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> 
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