[erlang-questions] separators before end

ok <>
Wed Sep 19 08:00:10 CEST 2007


On 19 Sep 2007, at 3:33 pm, Doug Edmunds wrote:

> Can someone tell me why it would be so difficult for Erlang
> to allow commas and semi-colons before the word ''end"?

Syntactically it would be easy.
>
> If there is a syntax error waiting to happen it is doing
> a copy/paste that doesn't add or take away a comma or
> semi-colon.

This doesn't happen to me, but I'm not a *heavy* user of Erlang,
so evidence from people who are would be useful.
> What is so bad about having an empty statement?

The fact that Erlang doesn't *HAVE* statements.  It only has
expressions.  What is the value of an empty expression?
Should
	if ... -> E1, ; ... -> En, ; end
have the same value as
	if ... -> E1 ; ... -> En end
and if so, how come the empty expression has so many different values?
If not, why not?

Where Erlang *does* need to allow extra semicolons is at the
*beginnings* of ifs, cases, and receives, so you can write
	case e0 of
	  ; p1 when g1 -> e1
	  ; ...
	  ; pn when gn -> en
	end
and be sure of having your punctuation right.

>
>
> --dae
>
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