New floor-rem, ceil-rem and round-rem.

* arith.c (trunc_rem): Move function to below round function.
Make second argument optional, defaulting to one.
(floor_rem, ceil_rem, round_rem): New functions.

* eval.c (eval_init): Registration of trunc-rem altered for
optional argument. New registrations for floor-rem, ceil-rem,
round=rem.

* txr.1: Documented for new functions folded with trunc-rem.

1 files changed, 28 insertions, 7 deletions

diff --git a/arith.c b/arith.c
index 483efa15..1dff8eb6 100644
--- a/arith.c
+++ b/arith.c
@@ -1090,13 +1090,6 @@ divzero:
   uw_throw(numeric_error_s, lit("mod: division by zero"));
 }
 
-val trunc_rem(val anum, val bnum)
-{
-  val quot = trunc(anum, bnum);
-  val rem = minus(anum, mul(quot, bnum));
-  return list(quot, rem, nao);
-}
-
 val floordiv(val anum, val bnum)
 {
   if (missingp(bnum))
@@ -1312,6 +1305,34 @@ val roundiv(val anum, val bnum)
   }
 }
 
+val trunc_rem(val anum, val bnum)
+{
+  val quot = trunc(anum, bnum);
+  val rem = minus(anum, mul(quot, if3(missingp(bnum), one, bnum)));
+  return list(quot, rem, nao);
+}
+
+val floor_rem(val anum, val bnum)
+{
+  val quot = floordiv(anum, bnum);
+  val rem = minus(anum, mul(quot, if3(missingp(bnum), one, bnum)));
+  return list(quot, rem, nao);
+}
+
+val ceil_rem(val anum, val bnum)
+{
+  val quot = ceildiv(anum, bnum);
+  val rem = minus(anum, mul(quot, if3(missingp(bnum), one, bnum)));
+  return list(quot, rem, nao);
+}
+
+val round_rem(val anum, val bnum)
+{
+  val quot = roundiv(anum, bnum);
+  val rem = minus(anum, mul(quot, if3(missingp(bnum), one, bnum)));
+  return list(quot, rem, nao);
+}
+
 val wrap_star(val start, val end, val num)
 {
   val modulus = minus(end, start);