Add bitwise logical functions

doc/teapot.lyx

@@ -5775,7 +5775,78 @@ x
 x
 \emph default
  is given in radians.
+\end_layout
 
+\begin_layout Description
+
+\series medium
+int
+\begin_inset space ~
+\end_inset
+
+
+\series default
+bitand
+\series medium
+(int
+\emph on
+
+\begin_inset space ~
+\end_inset
+
+v1,
+\begin_inset space ~
+\end_inset
+
+...
+\emph default
+) evaluates to the bitwise 
+\begin_inset Quotes eld
+\end_inset
+
+and
+\begin_inset Quotes erd
+\end_inset
+
+ of all the supplied values.
+\end_layout
+
+\begin_layout Description
+
+\series medium
+int
+\begin_inset space ~
+\end_inset
+
+
+\series default
+bitor
+\series medium
+(int
+\emph on
+
+\begin_inset space ~
+\end_inset
+
+v
+\emph default
+1,
+\emph on
+
+\begin_inset space ~
+\end_inset
+
+
+\emph default
+...) evaluates to the bitwise 
+\begin_inset Quotes eld
+\end_inset
+
+or
+\begin_inset Quotes erd
+\end_inset
+
+ of all the supplied values.
 \end_layout
 
 \begin_layout Description

src/common/func.c

@@ -511,6 +511,42 @@ static Token z_func(int argc, const Token argv[])
 }
 /*}}}*/
 
+typedef enum { LOG_AND, LOG_OR } LogicalFunction;
+
+static Token bitwise_func(int argc, const Token argv[], LogicalFunction lop)
+{
+  Token result;
+  int accum;
+  if (lop == LOG_AND) accum = -1;
+  else accum = 0;
+  for (size_t i = 0; i < argc; ++i) {
+    if (!INTPATIBLE(argv[i]))
+    {
+      result.type = EEK;
+      result.u.err =
+	mystrmalloc(_("Bitwise functions operate only on integers."));
+      return result;
+    }
+    int val = 0;
+    if (argv[i].type == INT) val = argv[i].u.integer;
+    if (lop == LOG_AND) accum = accum & val;
+    else accum = accum | val;
+  }
+  result.type = INT;
+  result.u.integer = accum;
+  return result;
+}
+
+static Token bitand_func(int argc, const Token argv[])
+{
+  return bitwise_func(argc, argv, LOG_AND);
+}
+
+static Token bitor_func(int argc, const Token argv[])
+{
+  return bitwise_func(argc, argv, LOG_OR);
+}
+
 /* e */ /*{{{*/
 static Token e_func(int argc, const Token argv[])
 {
@@ -1451,6 +1487,8 @@ Tfunc tfunc[]=
   { "substr", substr_func },
   { "strptime", strptime_func },
   { "time", time_func },
+  { "bitand", bitand_func },
+  { "bitor", bitor_func },
   { "", (Token (*)(int, const Token[]))0 }
 };
 /*}}}*/