new functions "random" and "randomseed".

2 files changed, 28 insertions, 6 deletions

diff --git a/manual.tex b/manual.tex
index e210a039..b3e37013 100644
--- a/manual.tex
+++ b/manual.tex
@@ -1,4 +1,4 @@
-% $Id: manual.tex,v 1.6 1996/02/05 21:32:19 roberto Exp roberto $
+% $Id: manual.tex,v 1.7 1996/02/09 16:37:58 roberto Exp roberto $
 
 \documentstyle[A4,11pt,bnf]{article}
 
@@ -32,7 +32,7 @@ Waldemar Celes Filho
 Departamento de Inform\'atica --- PUC-Rio
 }
 
-\date{\small \verb$Date: 1996/02/05 21:32:19 $}
+\date{\small \verb$Date: 1996/02/09 16:37:58 $}
 
 \maketitle
 
@@ -1293,9 +1293,10 @@ The library provides the following functions:
 \Deffunc{atan2}\Deffunc{ceil}\Deffunc{cos}\Deffunc{floor}
 \Deffunc{log}\Deffunc{log10}\Deffunc{max}\Deffunc{min}
 \Deffunc{mod}\Deffunc{sin}\Deffunc{sqrt}\Deffunc{tan}
+\Deffunc{random}\Deffunc{randomseed}
 \begin{verbatim}
-abs acos asin atan atan2 ceil cos floor
-log log10 max min  mod  sin  sqrt tan
+abs acos asin atan atan2 ceil cos floor log log10
+max min  mod  sin  sqrt tan random randomseed
 \end{verbatim}
 Most of them
 are only interfaces to the homonymous functions in the C library,
@@ -1309,6 +1310,12 @@ Both can be used with an unlimited number of arguments.
 
 The function \verb'mod' is equivalent to the \verb'%' operator in C.
 
+The functions \verb'random' and \verb'randomseed' are interfaces to
+the simple random generator functions \verb'rand' and \verb'srand',
+provided by ANSI C.
+The function \verb'random' returns pseudo-random numbers in the range
+$[0,1)$.
+
 
 \subsection{I/O Facilities} \label{libio}
 
diff --git a/mathlib.c b/mathlib.c
index 1092052a..cf5b6a8a 100644
--- a/mathlib.c
+++ b/mathlib.c
@@ -3,9 +3,9 @@
 ** Mathematics library to LUA
 */
 
-char *rcs_mathlib="$Id: mathlib.c,v 1.12 1995/10/09 12:48:38 roberto Exp roberto $";
+char *rcs_mathlib="$Id: mathlib.c,v 1.13 1995/11/10 17:54:31 roberto Exp roberto $";
 
-#include <stdio.h>              /* NULL */
+#include <stdlib.h>
 #include <math.h>
 
 #include "lualib.h"
@@ -184,6 +184,18 @@ static void math_rad (void)
  lua_pushnumber (d/180.*PI);
 }
 
+static void math_random (void)
+{
+  lua_pushnumber((double)(rand()%RAND_MAX) / (double)RAND_MAX);
+}
+
+static void math_randomseed (void)
+{
+  srand(lua_check_number(1, "randomseed"));
+}
+
+
+
 /*
 ** Open math library
 */
@@ -208,5 +220,8 @@ void mathlib_open (void)
  lua_register ("exp",   math_exp);
  lua_register ("deg",   math_deg);
  lua_register ("rad",   math_rad);
+ lua_register ("random",     math_random);
+ lua_register ("randomseed", math_randomseed);
+
  old_pow = lua_lockobject(lua_setfallback("arith", math_pow));
 }