Re: [Caml-list] Pattern matching of records

[Leonardo Laguna Ruiz <modlfo@gmail.com>]

Great! thank you very much guys!

Leonardo

On 2015-09-16 14:26, Thibault Suzanne wrote:
> There is no need to specify the origin module in front of each field :
>
> match s0 with
> | { S.a = 0; b = 0 } -> true
> | _ -> false
>
> Le 16/09/2015 14:19, Leonardo Laguna Ruiz a écrit :
>>
>> I have the following type
>>
>> (* File: S.ml *)
>> module S = struct
>>    type s =
>>       {
>>          a : int;
>>          b : int;
>>       }
>> end
>>
>>
>> I I have found that for creating records I can do as follows:
>>
>> (* File: main.ml *)
>> open S
>> let s0 = S.{ a = 0; b = 0}
>>
>>
>> However this does not work for pattern matching:
>>
>> (* this does not work *)
>> match s0 with
>> | S.{ a = 0 ; b = 0 } -> true
>> | _ -> false
>>
>>
>> These two alternatives work, but one with a warning and the other 
>> (depending on the type) is too verbose:
>>
>> (* this produces a warning *)
>> match s0 with
>> | { a = 0 ; b = 0 } -> true
>> | _ -> false
>>
>> (* this works *)
>> match s0 with
>> | { S.a = 0 ; S.b = 0 } -> true
>> | _ -> false
>>
>>
>> Is there any other way of writing pattern matches as compact as S.{ a 
>> = 0 ; b = 0 } ? (which is consistent to the construction of the same 
>> value)
>>
>> I know that it's possible to do:
>>
>> let open S in
>> match s0 with
>> | { a = 0 ; b = 0 } -> true
>> | _ -> false
>>
>> but the main reason I don't do it is because I have more records like:
>>
>> match s0,k0 with
>> | { S.a = 0 }, {K.a = 0 } -> true
>>
>>
>>
>> Best regards,
>>
>> Leonardo
>>
>>
>>
>
>