Fri Jun 29 09:49:11 CEST 2007

problem with dup and literals

123 dup 456 doesn't give 2 literals on the stack.. if i let dup copy
the literal, some other things go wrong.. maybe it's best to have dup
copy the literal, and solve the other problems in a second pass?

i found an optimization that solves it in one pass, by realizing

1 (2 3 !)   ->    <...> 1

where <...> stores the value with stack effect = 0.

other places where this might go wrong is where an explicit dup is
expected.. there are none outside of the '!' i think.