Try/Cond

[Richard Carlsson]

----- Original Message ----- 
From: "Luke Gorrie" <luke@REDACTED>
To: "Richard Carlsson" <richardc@REDACTED>
Cc: "Sean Hinde" <sean.hinde@REDACTED>; <erlang-questions@REDACTED>
Sent: Tuesday, October 21, 2003 8:56 PM
Subject: Re: Try/Cond


> Luke Gorrie <luke@REDACTED> writes:
>
> > "Richard Carlsson" <richardc@REDACTED> writes:
> >
> > > The current status is that it turned out that Erlang's scoping rules
> > > made it harder than we had expected to implement "cond" correctly
> > > (i.e., it's not just a trivial expansion into a nested case
> > > statement), so it was postponed until someone with a lot of spare time
> > > could have another look at it.
> >
> > Just add `let' too.
>
> Hmm, but Core Erlang already has `let'. Is the problem that you can't
> express cond in Core Erlang, or that you have to do something hard
> with it before it gets to Core? Or something else?

Representing a cond in Core Erlang is no problem, but there are several
things done with the code before the Core stage, and it would have been
nice if "cond" could be expanded into "case" expressions very early
(so that e.g. the debugger does not have to know anything about it). But
it was not as simple as that.

    /Richard