Maude-help mailing list

[Paco Durán <duran AT lcc.uma.es>]

Hi,

The usual solutions are the one that Julia gave and using the alternative 
pre-fix syntax:

 1 + - 2
 _-_(1, 2)

The reason why (1 + 2).Int doesn't work is because parsing is many sorted, 
for the kinds, and Int and List{Int} are in the same connected component. 

Best,

Paco


> On 6 May 2018, at 13:27, Julia Sapiña Sanchis 
> <jsapina AT dsic.upv.es>
>  wrote:
> 
> Hi Razvan,
> 
> If you want a list of two elements { 1, -2 } then try
> 
> parse 1 (- 2) .
> 
> and if you want the list of one element { 1-2 } then
> 
> parse (1 + - 2) .
> 
> Hope this helps.
> 
> Best regards,
> 
> Julia
> 
> El 06/05/2018 a las 13:16, Razvan Diaconescu escribió:
>> Does not seems to work?
>> Best,
>> Razvan
>> ------------------
>> Maude> mod LISTINT is protecting LIST{Int} . endm
>> Advisory: redefining module LISTINT.
>> Maude> parse 1 - 2 .
>> Warning: <standard input>, line 45: ambiguous term, two parses are:
>> 1 - 2
>> -versus-
>> 1 -2
>> Arbitrarily taking the first as correct.
>> Int: 1 - 2
>> Maude> parse 1 (-) 2 .
>> Warning: <standard input>, line 46: didn't expect token ):
>> 1 ( - ) <---*HERE*
>> Warning: <standard input>, line 46: no parse for term.
>>> On 6 May 2018, at 14:00, Santiago Escobar 
>>> <sescobar AT dsic.upv.es
>>>  
>>> <mailto:sescobar AT dsic.upv.es>>
>>>  wrote:
>>> 
>>> A very simple solution is m (- n) for list and m (-) n for integer.
>>> 
>>> --Santiago
>>> 
>>>> On 6 May 2018, at 12:54, Razvan Diaconescu 
>>>> <Razvan.Diaconescu AT ymail.com
>>>>  
>>>> <mailto:Razvan.Diaconescu AT ymail.com>>
>>>>  wrote:
>>>> 
>>>> Thanks a lot Santiago,
>>>> 
>>>> I knew this solution, but I wondered whether there is an
>>>> alternative to this such as sort disambiguation or just something else.
>>>> And I do not understand why (m - n).Int does not work.
>>>> 
>>>> Best,
>>>> Razvan
>>>> 
>>>>> On 6 May 2018, at 13:40, Santiago Escobar 
>>>>> <sescobar AT dsic.upv.es
>>>>>  
>>>>> <mailto:sescobar AT dsic.upv.es>>
>>>>>  wrote:
>>>>> 
>>>>> Best thing is to rename __ from LIST{Int} into another symbol, eg _._ 
>>>>> or _:_.
>>>>> 
>>>>> --Santiago
>>>>> 
>>>>>> On 6 May 2018, at 11:40, 
>>>>>> <razvan.diaconescu AT ymail.com
>>>>>>  
>>>>>> <mailto:razvan.diaconescu AT ymail.com>>
>>>>>>  
>>>>>> <razvan.diaconescu AT ymail.com<mailto:razvan.diaconescu AT ymail.com>>
>>>>>>  wrote:
>>>>>> 
>>>>>> Hi,
>>>>>> 
>>>>>> How do you solve the following ambiguity problem:
>>>>>> 
>>>>>> When working with LIST{Int} list of integers (which may
>>>>>> be a very common module to work with) I cannot find a way
>>>>>> to disambiguate m - n, where m and n are integers.
>>>>>> The system considers two parses of this,
>>>>>> as the list m (- n) and as the integer number m - n.
>>>>>> 
>>>>>> I have tried (m - n).Int and it does not work.
>>>>>> 
>>>>>> Any help is greatly appreciated.
>>>>>> 
>>>>>> Thanks,
>>>>>> Razvan Diaconescu