feat: add random and shuffle.

Jellyfin.Plugin.SmartPlaylist/Lisp/Interpreter.cs

@@ -78,6 +78,23 @@ namespace Jellyfin.Plugin.SmartPlaylist.Lisp {
                     (sort fc list00)))
                 """
             );
+            this["rand"] = e.eval(
+                """
+                (lambda
+                  (. a)
+                  (cond
+                    ((null a) (random))
+                    ((null (cdr a)) (% (random) (car a)))
+                    (t (+
+                         (car a)
+                         (%
+                           (random)
+                           (-
+                             (car (cdr a))
+                             (car a)))))))
+                """
+            );
+            this["shuf"] = new Symbol("shuffle");
         }
     }
 
@@ -114,8 +131,10 @@ namespace Jellyfin.Plugin.SmartPlaylist.Lisp {
     public class Builtins : Dictionary<string, Function> {
 
         private static Dictionary<string, Type?> ResolvedTypes = new Dictionary<string, Type?>();
+        private Random Random;
 
         public Builtins() : base() {
+            Random = new Random();
             this["atom"] = _atom;
             this["eq"] = _eq;
             this["car"] = _car;
@@ -146,11 +165,17 @@ namespace Jellyfin.Plugin.SmartPlaylist.Lisp {
             this["string<"] = (x) => _cmp((String a, String b) => a < b, x);
             this["string<="] = (x) => _cmp((String a, String b) => a <= b, x);
 
-
             this["haskeys"] = _haskeys;
             this["getitems"] = _getitems;
             this["invoke"] = _invoke;
             this["invoke-generic"] = _invoke_generic;
+
+            this["random"] = (x) => new Lisp.Integer(Random.Next());
+            this["shuffle"] = (x) => {
+                var newx = ((Lisp.Cons) x.First()).ToList().ToArray();
+                Random.Shuffle<Expression>(newx);
+                return Lisp.Cons.FromList(newx);
+            };
         }
         private static T _agg<T>(Func<T, T, T> op, IEnumerable<Expression> args) where T : Expression {
             T agg = (T) args.First();

Tests/Tests.cs

@@ -233,6 +233,9 @@ namespace Tests
             Assert.Equal("10", e.eval("(fold (lambda (a b) (+ a b)) 0 (list 1 2 3 4))").ToString());
             Assert.Equal("(2 3 4 5 6 7)", e.eval("(append (list 2 3 4) (list 5 6 7))").ToString());
             Assert.Equal("(1 2 3 4 5 6 7)", e.eval("(qsort (lambda (a b) (> a b)) (list 5 4 7 3 2 6 1))").ToString());
+
+            //Assert.Equal("", e.eval("(rand)").ToString());
+            //Assert.Equal("", e.eval("(shuf (list 0 1 2 3 4 5 6))").ToString());
         }
     }
 }