lib: eliminate reduce-left from n-ary math ops.

Using reduce-left is inefficient; it conses up a list.
We can decimate the stacked arguments without consing.

* lib.c (nary_op): Replace reduce_left with iteration.
(nary_simple_op): New function, variant of nary_op
useable by functions that have a mandatory argument
passed separately from the argument list.
(minusv, divv): Replace reduce_left with iteration.
(maxv, minv): Replace reduce_left with nary_simple_op.
(abso_self): New static function.
(gcdv, lcmv): Replace reduce_left with nary_op.

* lib.h (nary_simple_op): Declared.

1 files changed, 2 insertions, 0 deletions

diff --git a/lib.h b/lib.h
index f5e4194f..f39f075a 100644
--- a/lib.h
+++ b/lib.h
@@ -661,6 +661,8 @@ val numberp(val num);
 val nary_op(val self, val (*bfun)(val, val),
             val (*ufun)(val self, val),
             struct args *args, val emptyval);
+val nary_simple_op(val self, val (*bfun)(val, val),
+                   struct args *args, val emptyval);
 val plus(val anum, val bnum);
 val plusv(struct args *);
 val minus(val anum, val bnum);