Re: simple 16-bit random number generator

Hi John!

On Fr, 17 Sep 2010, John Little wrote:

> On Sep 18, 3:05 am, Bee <200...@calcentral.com> wrote:
> function! Random()
> if !exists("s:seeded")
> call libcallnr("libc.so.6", "srand", localtime() )
> let s:seeded = 1
> endif
> return libcallnr("libc.so.6", "rand", 0 ) % 65536
> endfun
>
> You might have to adjust that "libc.so.6" for your OS.

This reminds me, that I have wished a rand() function for very long.

So here is a very simple patch. It doesn't add much to the footprint. I
am not sure, how portable the code is, though:

--- a/runtime/doc/eval.txt
+++ b/runtime/doc/eval.txt
@@ -4522,6 +4522,9 @@
This can be used to avoid some things that would remove the
popup menu.

+rand() *rand()*
+ Returns a pseudo-random positive integer Number.
+
*E726* *E727*
range({expr} [, {max} [, {stride}]]) *range()*
Returns a |List| with Numbers:
diff --git a/src/eval.c b/src/eval.c
--- a/src/eval.c
+++ b/src/eval.c
@@ -653,6 +653,7 @@
static void f_prevnonblank __ARGS((typval_T *argvars, typval_T *rettv));
static void f_printf __ARGS((typval_T *argvars, typval_T *rettv));
static void f_pumvisible __ARGS((typval_T *argvars, typval_T *rettv));
+static void f_rand __ARGS((typval_T *argvars, typval_T *rettv));
static void f_range __ARGS((typval_T *argvars, typval_T *rettv));
static void f_readfile __ARGS((typval_T *argvars, typval_T *rettv));
static void f_reltime __ARGS((typval_T *argvars, typval_T *rettv));
@@ -7829,6 +7830,7 @@
{"prevnonblank", 1, 1, f_prevnonblank},
{"printf", 2, 19, f_printf},
{"pumvisible", 0, 0, f_pumvisible},
+ {"rand", 0, 0, f_rand},
{"range", 1, 3, f_range},
{"readfile", 1, 3, f_readfile},
{"reltime", 0, 2, f_reltime},
@@ -14224,6 +14226,18 @@
rettv->vval.v_number = 1;