Hi,

ludo@chbouib.org (Ludovic Courtès) writes:

> Actually, no: the test does a `define' _within_ the body of `begin', so
> I *think* this qualifies as an internal define, and internal defines are
> equivalent to `letrec' (Section 5.2.2).

I was wrong: `define' within `begin' does not qualify as an "internal
define", so the test "binding is created before expression is evaluated"
was incorrect (or over-specified compared to R5RS[*]).

After further discussion with Andy, I committed the patch below to HEAD.
It inverts the order of expression evaluation and `scm_sym2var' in
`scm_m_define ()' (which is concerned only with top-level defines),
thereby fixing the `(define round round)' case.  At the same time, it
breaks the aforementioned test from `syntax.test', but there's nothing
wrong with that.

For 1.8, I'm pretty much inclined to commit a similar patch, i.e., where
`module-make-local-var!' and `scm_m_define' are copied from HEAD.  This
would break code that does things like:

  (define foo (begin (set! foo 1) (+ foo 1)))

but I think it's reasonable to break such code (which relies on
non-R5RS-compliant behavior anyway), especially given the performance
gain we get in return.  What do you think?

Thanks,
Ludovic.

[*] FWIW, the wording for `define' in the newly-released R5.93RS
    (Section 9.3.1) is the same as that of R5RS (Section 5.2.1).