[Caml-list] Syntax errors with match and interface files

[Caml-list] Syntax errors with match and interface files

[Jonathan Roewen]

Hi,

I'm getting a curious syntax error:

in my Key.mli file, I have:

val kEnter: int;
val kBksp: int;

then, in Console.ml, I'm trying something like:

try
let put c = putch c; Queue.add c buffer in
match char_code with
| Key.kEnter -> put '\n'
| Key.kBksp -> put '\b'
| ch -> put (Key.to_char ch)
with Key.Not_printable -> ()

but I get a syntax error at any match case with Key.xxx. I tried
replacing with arbitrary numbers, and the errors at those lines
disappear.

Is this a problem with the ocaml[opt] compiler?

Jonathan

Re: [Caml-list] Syntax errors with match and interface files

[Stephane Glondu]

Hi,

Jonathan Roewen wrote:
> I'm getting a curious syntax error:
>
> [...]
>
> try
> let put c = putch c; Queue.add c buffer in
> match char_code with
> | Key.kEnter -> put '\n'
> | Key.kBksp -> put '\b'
> | ch -> put (Key.to_char ch)
> with Key.Not_printable -> ()

You cannot use defined variables as patterns (this is a common mistake).
Variables appearing in a pattern are always bound to (parts) of the
matched value. Something close to what you want would be :

try
let put c = putch c; Queue.add c buffer in
match char_code with
| ch when ch = Key.kEnter -> put '\n'
| ch when ch = Key.kBksp -> put '\b'
| ch -> put (Key.to_char ch)
with Key.Not_printable -> ()


Stephane Glondu.

Re: [Caml-list] Syntax errors with match and interface files

[skaller]

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On Fri, 2005-07-22 at 10:42 +1200, Jonathan Roewen wrote:
> Hi,
> 
> I'm getting a curious syntax error:
> 
> in my Key.mli file, I have:
> 
> val kEnter: int;
> val kBksp: int;

Because of the curious semicolons .. which are
infix sequencing operators used in expressions.
val binding in an interface is not an expression..

-- 
John Skaller <skaller at users dot sourceforge dot net>


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