* arith.c (gcd): Allow zeros. Don't issue "non-integral"

exception if MPI fails.
(floorf, ceili): Map integer argument to itself.
(tang, asine, acosi): New functions.

* eval.c (eval_init): New intrinsics: tan, asin, acos.

* lib.h (tang, asine, acosi): Declared.

* txr.1: Documented gcd, abs, floor, ceil, sin, cos, tan
asin, acos, atan, log, and exp.

* txr.vim: Highlighting for tang, asine, acosi.

6 files changed, 141 insertions, 3 deletions

diff --git a/ChangeLog b/ChangeLog
index 82e41883..b71ef931 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,21 @@
 2012-03-29  Kaz Kylheku  <kaz@kylheku.com>
 
+	* arith.c (gcd): Allow zeros. Don't issue "non-integral"
+	exception if MPI fails.
+	(floorf, ceili): Map integer argument to itself.
+	(tang, asine, acosi): New functions.
+
+	* eval.c (eval_init): New intrinsics: tan, asin, acos.
+
+	* lib.h (tang, asine, acosi): Declared.
+
+	* txr.1: Documented gcd, abs, floor, ceil, sin, cos, tan
+	asin, acos, atan, log, and exp.
+
+	* txr.vim: Highlighting for tang, asine, acosi.
+
+2012-03-29  Kaz Kylheku  <kaz@kylheku.com>
+
 	* arith.c (dmod): New static function.
 	(mod): Use dmod instead of fmod directly, to calculate
 	the correct semantics for combinations of
diff --git a/arith.c b/arith.c
index a8cfb578..208a06a1 100644
--- a/arith.c
+++ b/arith.c
@@ -1283,6 +1283,9 @@ val gcd(val anum, val bnum)
   if (!integerp(anum) || !integerp(bnum))
     goto inval;
 
+  if (zerop(anum))
+    return zero;
+
   if (fixnump(anum))
     anum = bignum(c_num(anum));
 
@@ -1292,21 +1295,28 @@ val gcd(val anum, val bnum)
   n = make_bignum();
 
   if (mp_gcd(mp(anum), mp(bnum), mp(n)) != MP_OKAY)
-    goto inval;
+    goto bad;
 
   return n;
 inval:
   uw_throwf(error_s, lit("gcd: non-integral operands ~s ~s"),
             anum, bnum, nao);
+bad:
+  uw_throwf(error_s, lit("gcd: operation failed on ~s ~s"),
+            anum, bnum, nao);
 }
 
 val floorf(val num)
 {
+  if (integerp(num))
+    return num;
   return flo(floor(c_flo(to_float(lit("floor"), num))));
 }
 
 val ceili(val num)
 {
+  if (integerp(num))
+    return num;
   return flo(ceil(c_flo(to_float(lit("ceil"), num))));
 }
 
@@ -1320,6 +1330,21 @@ val cosi(val num)
   return flo(cos(c_flo(to_float(lit("cos"), num))));
 }
 
+val tang(val num)
+{
+  return flo(tan(c_flo(to_float(lit("tan"), num))));
+}
+
+val asine(val num)
+{
+  return flo(asin(c_flo(to_float(lit("asin"), num))));
+}
+
+val acosi(val num)
+{
+  return flo(acos(c_flo(to_float(lit("acos"), num))));
+}
+
 val atang(val num)
 {
   return flo(atan(c_flo(to_float(lit("atan"), num))));
diff --git a/eval.c b/eval.c
index 4a028ca4..3fdee26f 100644
--- a/eval.c
+++ b/eval.c
@@ -2191,6 +2191,9 @@ void eval_init(void)
   reg_fun(intern(lit("ceil"), user_package), func_n1(ceili));
   reg_fun(intern(lit("sin"), user_package), func_n1(sine));
   reg_fun(intern(lit("cos"), user_package), func_n1(cosi));
+  reg_fun(intern(lit("tan"), user_package), func_n1(tang));
+  reg_fun(intern(lit("asin"), user_package), func_n1(asine));
+  reg_fun(intern(lit("acos"), user_package), func_n1(acosi));
   reg_fun(intern(lit("atan"), user_package), func_n1(atang));
   reg_fun(intern(lit("log"), user_package), func_n1(loga));
   reg_fun(intern(lit("exp"), user_package), func_n1(expo));
diff --git a/lib.h b/lib.h
index 52695229..2167e642 100644
--- a/lib.h
+++ b/lib.h
@@ -431,6 +431,9 @@ val floorf(val);
 val ceili(val);
 val sine(val);
 val cosi(val);
+val tang(val);
+val asine(val);
+val acosi(val);
 val atang(val);
 val loga(val);
 val expo(val);
diff --git a/txr.1 b/txr.1
index 4a103abb..6f192f10 100644
--- a/txr.1
+++ b/txr.1
@@ -6854,9 +6854,100 @@ once, with a "remainder" of 0.25.
 
 .SS Arithmetic function gcd
 
+.TP
+Syntax:
+
+  (gcd <left> <right>)
+
+.TP
+Description:
+
+The gcd function computes the greatest common divisor: the largest positive
+integer which divides both arguments.
+
+Operands <left> and <right> must be integers, or else an exception is thrown.
+
+The value of (gcd 0 x) is 0 for all x, including 0.
+
+The value of (gcd x 123) is is (abs x) for all x.
+
+Negative operands are permitted; this operation effectivelly ignores sign, so
+that the value of (gcd x y) is the same as (gcd (abs x) (abs y)) for all
+x and y.
+
 .SS Arithmetic function abs
 
-.SS Arithmetic functions floor, ceil, sin, cos, atan, log, exp
+.TP
+Syntax:
+
+  (abs <number>)
+
+.TP
+Description:
+
+The abs function computes the absolute value of the given number. If the number
+is positive, it is returned. If the number is negative, its additive inverse is
+returned: a positive number of the same type with exactly the same magnitude.
+
+.SS Arithmetic functions floor, ceil
+
+.TP
+Syntax:
+
+  (floor <number>)
+  (ceil <number>)
+
+.TP
+Description:
+
+The floor function returns the highest integer which does not exceed
+the argument. The ceiling function returns the lowest integer which does
+not exceed the argument.
+
+If the argument is an integer, it is simply returned.
+
+If the argument is a float, then the value returned is a float.
+For instance (floor 1.1) returns 1.0.
+
+.SS Arithmetic functions sin, cos, tan, asin, acos, atan
+
+.TP
+Syntax:
+
+  (sin <radians>)
+  (cos <radians>)
+  (tan <radians>)
+  (atan <slope>)
+  (asin <num>)
+  (acos <num>)
+
+.TP
+Description:
+
+These trigonometric functions convert their argument to floating point and
+return a float result. The sin, cos and tan functions compute the sine and
+cosine and tangent of the argument. The argument represents an angle expressed
+in radians. The atan, acos and asin are their respective inverse functions.
+The argument to asin and acos must be in the range -1.0 to 1.0.
+
+.SS Arithmetic functions log, exp
+
+.TP
+Syntax:
+
+  (exp <number>)
+  (log <number>)
+
+.TP
+Description:
+
+The exp function calculates the value of the transcendental number e raised to
+the specified exponent.
+
+The log function calculates the base e logarithm of its argument, which must
+be a positive value.
+
+Integer arguments are converted to floats.
 
 .SS Arithmetic functions expt, sqrt, isqrt
 
diff --git a/txr.vim b/txr.vim
index 5ae8683c..42a086f2 100644
--- a/txr.vim
+++ b/txr.vim
@@ -44,7 +44,7 @@ syn keyword txl_keyword contained memq memql memqual tree-find some
 syn keyword txl_keyword contained remq remql remqual
 syn keyword txl_keyword contained all none eq eql equal + - * / abs trunc mod
 syn keyword txl_keyword contained expt exptmod sqrt isqrt gcd 
-syn keyword txl_keyword contained floor ceil sin cos atan log exp
+syn keyword txl_keyword contained floor ceil sin cos tan asin acos atan log exp
 syn keyword txl_keyword contained fixnump bignump integerp floatp
 syn keyword txl_keyword contained numberp zerop evenp oddp >
 syn keyword txl_keyword contained zerop evenp oddp > < >= <= max min