Re: [Caml-list] partial match in let

[luc.maranget@inria.fr (Luc Maranget)]

> 
> Wish: I had like a way to avoid the partial match warning in code like
> 
> let [x;y] = f (x) in foo
> 
> Because if foo is long writing
> 
> match f(x) with [x;y] -> foo | _ -> assert false
> 
> is really ennoying, especially if you have a long sequence of let.
> 
> I find usefull the partial match warning for match and function but not 
> for let (if you write a let, I think you are aware that your matching 
> will be partial for any data type with more than one constructor, you do 
> not need a warning)
> 
> -- 
> Christophe Raffalli


I think the warning clearly is useful even in this situation of
a pattern in let.

In fact it can even be argued that 'let pat = exp in exp' should be legal
only when 'pat' provable cannot fail.
And the is camlp4 'revised syntax' approach, as far as I remember.


I also remark that your sentence
'I think you are aware that your matching 
will be partial for any data type with more than one constructor, you do 
not need a warning'
Does not apply to novices or in case of type alteration.


Besides a simple solution using a function has been given.


Cheers, 

-- 
Luc Maranget