Re: [Caml-list] Are record types generative?

[Evgeny Roubinchtein <zhenya1007@gmail.com>]

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One source that explains how record labels are disambiguated is:
https://realworldocaml.org/v1/en/html/records.html#reusing-field-names.

Parenthetically, it seems to me that your question is hardly related to the
subject of this thread, so it may have been better to start a new thread in
this case, than to piggy-back onto an existing thread.

-- 
Best,
Evgeny ("Zhenya")

On Fri, Feb 2, 2018 at 3:07 PM, Toby Kelsey <toby.kelsey@gmail.com> wrote:

> On 24/01/18 08:43, Jacques Garrigue wrote:
>
>> I.e., types can be used to optimize a program, but they do not change its
>> semantics.
>> It’s true of so-called “overloaded” record labels, it’s true of a labeled
>> and default arguments
>> (which use type information for compilation, but not semantics), it’s
>> true of objects,
>>   it’s true of GADT pattern-matching (again optimized), etc…
>>
>
> type foo = { x : int }
> type bar = { x : string }
>
> let f r = r.x           (* OK: uses bar *)
> let f r = (r:foo).x  (* OK: uses foo *)
> let f r = (r.x : int) (* type error - wrong type inferred *)
>
>
> Aren't the semantics different? 'f' has different types in the first two
> definitions, And why does type inference fail for the last example?
>
> Toby
>
>
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