Re: [Caml-list] Why do input* and readdir throw End_of_file ... annoying!

[Ville-Pertti Keinonen <will@exomi.com>]

> I'm pretty convinced that having the input* functions and readdir
> throw End_of_file when they run out of data is wrong. Instead
> 'readdir' (for example) should be prototyped as:
>
> readdir : dir_handle -> string option
>
> and the functions should return None when they run out of data.
> Either that or alternative forms which don't throw exceptions should
> be available.

I don't think it's necessarily such a clear requirement, unless you are 
assuming the interface for some particular language.

Since exceptions are reasonably inexpensive in O'Caml, and used for 
things such as Not_found in basic collection types, using exceptions to 
indicate the end of some particular set of values seems reasonable, to 
me.

Writing a try ... with statement isn't really that different from a 
match statement except for the fact that you can handle exceptional 
circumstances generated by several expressions in the with ... part of 
a try ... with statement - if anything, that's more permissive.

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