From e54cd7d4d63d866bf17576d3cac72d6ae51cbcfa Mon Sep 17 00:00:00 2001
From: Kaz Kylheku <kaz@kylheku.com>
Date: Wed, 13 Jan 2016 23:31:16 -0800
Subject: Fix omission: the / function becomes n-ary.

* eval.c (eval_init): Register / function to divv instead of divi.

* lib.c (divv): New function.

* lib.h (divv): Declared.

* txr.1: Documented.
---
 eval.c |  2 +-
 lib.c  | 17 +++++++++++++++++
 lib.h  |  1 +
 txr.1  |  8 ++++++--
 4 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/eval.c b/eval.c
index e83a8954..34d73304 100644
--- a/eval.c
+++ b/eval.c
@@ -4776,7 +4776,7 @@ void eval_init(void)
   reg_fun(intern(lit("trunc-rem"), user_package), func_n2(trunc_rem));
   reg_fun(intern(lit("wrap"), user_package), func_n3(wrap));
   reg_fun(intern(lit("wrap*"), user_package), func_n3(wrap_star));
-  reg_fun(intern(lit("/"), user_package), func_n2o(divi, 1));
+  reg_fun(intern(lit("/"), user_package), func_n1v(divv));
   reg_fun(intern(lit("expt"), user_package), func_n0v(exptv));
   reg_fun(intern(lit("exptmod"), user_package), func_n3(exptmod));
   reg_fun(intern(lit("isqrt"), user_package), func_n1(isqrt));
diff --git a/lib.c b/lib.c
index c0c8b5de..2000349c 100644
--- a/lib.c
+++ b/lib.c
@@ -2650,6 +2650,23 @@ val mulv(struct args *nlist)
   return nary_op(mul, nlist, one);
 }
 
+val divv(val dividend, struct args *nlist)
+{
+  cnum index = 0;
+  val fi;
+
+  if (!args_more(nlist, 0))
+    return divi(one, dividend);
+
+  fi = args_get(nlist, &index);
+
+  if (!args_more(nlist, 0))
+    return divi(dividend, fi);
+
+  return reduce_left(func_n2(divi), args_get_list(nlist),
+                     divi(dividend, fi), nil);
+}
+
 val logandv(struct args *nlist)
 {
   return nary_op(logand, nlist, negone);
diff --git a/lib.h b/lib.h
index 83b81c24..c07bc863 100644
--- a/lib.h
+++ b/lib.h
@@ -602,6 +602,7 @@ val neg(val num);
 val abso(val num);
 val mul(val anum, val bnum);
 val mulv(struct args *);
+val divv(val dividend, struct args *);
 val trunc(val anum, val bnum);
 val mod(val anum, val bnum);
 val trunc_rem(val anum, val bnum);
diff --git a/txr.1 b/txr.1
index dcf89f40..30017711 100644
--- a/txr.1
+++ b/txr.1
@@ -26837,7 +26837,7 @@ A character may not be an operand of multiplication.
 
 .coNP Functions @, / @ trunc, @ mod and @ trunc-rem
 .synb
-.mets (/ <> [ dividend ] << divisor )
+.mets (/ <> [ dividend ] << divisor *)
 .mets (trunc < dividend << divisor )
 .mets (mod < dividend << divisor )
 .mets (trunc-rem < dividend << divisor )
@@ -26853,7 +26853,11 @@ converted to floating-point type, if necessary. If
 is omitted,
 then it is taken to be
 .code 1.0
-and the function calculates the reciprocal.
+and the function calculates the reciprocal. Of these division functions,
+only this one may be called with just one argument, or with more than two
+arguments.  If there are more than two arguments, then each additional argument
+is treated as an additional divisor which further divides the result of the
+division by the previous divisors.
 
 The
 .code trunc
-- 
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