matcher: fix broken @(let @a @(some @a)) test case.

This is caused by the way the loop match compiler moves the
matching logic into a guard, which causes a re-ordering of the
variable assignments which interferes with backreferencing
when @(some) is embedded into a @(let), and probably other
situations. The issues is that the backreferencing equal
tests can be reordered to occur before the assignment which
sets the intial value of the backreferenced variable:
cart before the horse kind of thing.

* share/txr/stdlib/match.tl (compile-loop-match): Do not add
the submatch into the guard sequence. Thus guard1's vars and
var-exprs, move into into the main compiled-match,
and guard1's guard-expr moves into guard0. Thus guard1
disappears, guard0 becomes guard.

* tests/011/patmatch.tl: New test case that is also fixed,
and which was not fixed by a different approach to the problem
that I scrapped.

0 files changed, 0 insertions, 0 deletions