On 15 Mar 2000, Julian Assange wrote:
>
> let .. in
> let .. in ...
>
> seems such a common construct in caml that it could do with some
> syntatic sugar. I often see let..in run to 5-20 clauses. This appears
> incredibly ugly compared to the equivalent haskell code, is harder to
> read and takes longer to write due to the clutter of the surrounding
> token magic. Has anyone thought about applying layout in general to
> ocaml, or otherwise sugaring let...in? Is there any reason why the BNF
>
> let {name = expr}+ in
>
> would be ambiguous?
I guess one can write:
let silly f=
let x=List.map f z=3 in
...
which can be read either:
let silly f=
let x=List.map f in
let z=3 in
...
or:
let silly f=
let x=List.map in
let f z=3 in
...
Of course, if your definition aren't mutually recursive, you can use 'and'
to separate two deifferent definitons:
let x=t
and y=u
and ...
and z=v in
...
which is not so long to write, unambigous and readable (I find).
> The only other haskell features I frequently miss, are list
> comprehensions and multiple argument pattern matching.
I don't understand exactly what you mean by 'multiple argument pattern
matching', but I guess you could just use a tuple-pattern matching:
let f a b c=
match a,b,c with
...
which allows you to match several arguments at once.
Hypocoristiquement,
Jym.
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