Convert each-family operators to use iter-begin.

With this change we can do (each ((x vec)) ...) with
reasonable efficiency, because we are no longer marching
through the vector with cdr, copying the suffix.

* eval.c (get_iter_f): New global variable.
(op_each): Obtain iterators for all the objects with
iter_begin, instead of treating them as lists. Probe the
iterators for termination with iter_more, get the items with
iter_item instead of car and step with iter_step instead of
cdr.
(eval_init): gc-protect the get_iter_f function and initialize
it.

* share/txr/stdlib/compiler.tl (expand-each): Replace the
car/cdr and null testing with iter-init, iter-more, iter-item
and iter-step.

0 files changed, 0 insertions, 0 deletions