[plt-scheme] to define, or to let
On Sat, Mar 20, 2004 at 10:26:42PM -0500, Eli Barzilay wrote:
> For list-related administrative tasks:
> http://list.cs.brown.edu/mailman/listinfo/plt-scheme
>
> On Mar 20, Richard Cleis wrote:
> > Syntax: <Bindings> should have the form ((<variable1> <init1>) ...),
> >
> > One restriction on letrec is very important: it must be possible to
> > evaluate each <init> without assigning or referring to the value of
> > any <variable>. If this restriction is violated, then it is an
> > error.
>
> Section 1.3.2:
>
> When speaking of an error situation, this report uses the phrase "an
> error is signalled" to indicate that implementations must detect and
> report the error. If such wording does not appear in the discussion
> of an error, then implementations are not required to detect or
> report the error, though they are encouraged to do so. An error
> situation that implementations are not required to detect is usually
> referred to simply as "an error."
Which is why it's dangerous and non-portable to rely on the
initialization order.
--
Bradd W. Szonye
http://www.szonye.com/bradd