New function: shuffle.

* eval.c (eval_init): Register shuffle as intrinsic.

* lib.c (shuffle): New function.

* lib.h (shuffle): Declared.

1 files changed, 21 insertions, 0 deletions

diff --git a/txr.1 b/txr.1
index 33fe9c35..374e1f31 100644
--- a/txr.1
+++ b/txr.1
@@ -19544,6 +19544,27 @@ For strings and vectors,
 .code sort
 is not stable.
 
+.coNP Function @ shuffle
+.synb
+.mets (shuffle << sequence )
+.syne
+.desc
+The
+.code shuffle
+function pseudo-randomly rearranges the elements of
+.metn sequence .
+This is performed in place:
+.meta sequence
+object is modified.
+
+The return value is
+.meta sequence
+itself.
+
+The rearrangement depends on pseudo-random numbers obtained from the
+.code rand
+function.
+
 .coNP Function @ sort-group
 .synb
 .mets (sort-group < sequence >> [ keyfun <> [ lessfun ]])