feat: add default implementations of procedures.

Jellyfin.Plugin.SmartPlaylist/Lisp/Compiler/Parser.cs

@@ -211,7 +211,7 @@ namespace Jellyfin.Plugin.SmartPlaylist.Lisp.Compiler {
         public override string ToString() {
             return _value.ToString();
         }
-        public static Atom FromBase(object o) {
+        public static Expression FromBase(object o) {
             switch (o) {
                 case bool b:
                     return new Boolean(b);
@@ -219,6 +219,8 @@ namespace Jellyfin.Plugin.SmartPlaylist.Lisp.Compiler {
                     return new Integer(i);
                 case string s:
                     return new String(s);
+                case IEnumerable<object> e:
+                    return new List(e.Select(x => Object.FromBase(x)).ToList());
                 default:
                     return new Object(o);
             }
@@ -267,6 +269,9 @@ namespace Jellyfin.Plugin.SmartPlaylist.Lisp.Compiler {
         public Parser(StringTokenStream tokens) {
             _sts = tokens;
         }
+        public Parser(string s) {
+            _sts = StringTokenStream.generate(s);
+        }
 
         public Expression parse() {
             Token<string> token = _sts.Get();

Jellyfin.Plugin.SmartPlaylist/Lisp/Interpreter.cs

@@ -65,7 +65,7 @@ namespace Jellyfin.Plugin.SmartPlaylist.Lisp {
             return null;
         }
         public void Set(string k, Expression v) {
-            Add(k, v);
+            this[k] = v;
         }
 
         public IEnvironment<string, Expression>? Find(string k) {
@@ -76,6 +76,12 @@ namespace Jellyfin.Plugin.SmartPlaylist.Lisp {
         }
     }
 
+    public class DefaultEnvironment: Environment {
+        public DefaultEnvironment() {
+            this["find"] = new Parser("(lambda (item list) (if (= list ()) nil (if (= item (car list)) (car list) (find item (cdr list)))))").parse();
+        }
+    }
+
     public class SubEnvironment : Dictionary<string, Expression>, IEnvironment<string, Expression> {
         private IEnvironment<string, Expression> _super;
         public SubEnvironment(IEnvironment<string, Expression> super) {
@@ -112,6 +118,7 @@ namespace Jellyfin.Plugin.SmartPlaylist.Lisp {
             this["<="] = _le;
             this["eq?"] = _eq;
             this["="] = _eq;
+            this["!="] = _ne;
             this["abs"] = _abs;
             this["append"] = _append;
             this["begin"] = _begin;
@@ -123,7 +130,6 @@ namespace Jellyfin.Plugin.SmartPlaylist.Lisp {
             this["haskeys"] = _haskeys;
             this["getitems"] = _getitems;
             this["invoke"] = _invoke;
-            //this[new Symbol("!=")] = _ne;
         }
 
         private static T _agg<T>(Func<T, T, T> op, IList<T> args) {
@@ -375,6 +381,11 @@ namespace Jellyfin.Plugin.SmartPlaylist.Lisp {
             _builtins = builtins;
             _builtinsLater = builtinsLater;
         }
+        public Executor(IEnvironment<string, Expression> environment) {
+            _environment = environment;
+            _builtins = new Builtins();
+            _builtinsLater = new BuiltinsLater();
+        }
         public Executor() {
             _environment = new Environment();
             _builtins = new Builtins();
@@ -412,6 +423,8 @@ namespace Jellyfin.Plugin.SmartPlaylist.Lisp {
                     return i;
                 case Compiler.String s:
                     return s;
+                case Compiler.Object o:
+                    return o;
                 case Procedure p:
                     return p;
                 case List list:

Jellyfin.Plugin.SmartPlaylist/ScheduledTasks/GeneratePlaylist.cs

@@ -104,7 +104,7 @@ namespace Jellyfin.Plugin.SmartPlaylist.ScheduledTasks {
         private IEnumerable<Guid> FilterPlaylistItems(IEnumerable<BaseItem> items, User user, SmartPlaylistDto smartPlaylist) {
             List<Guid> results = new List<Guid>();
             Expression expression = new Parser(StringTokenStream.generate(smartPlaylist.Program)).parse();
-            Executor executor = new Executor();
+            Executor executor = new Executor(new DefaultEnvironment());
             executor.environment.Set("user", new Lisp_Object(user));
             foreach (var i in items) {
                 executor.environment.Set("item", new Lisp_Object(i));

Tests/Tests.cs

@@ -172,5 +172,12 @@ namespace Tests
             r = e.eval("(begin (define find (lambda (item list) (if (= list ()) nil (if (= item (car list)) (car list) (find item (cdr list)))))) (find 0 (1 2 3 4)))");
             Assert.Equal(string.Format("{0}", r), "nil");
         }
+
+        [Fact]
+        public static void DefaultEnvironmentTest() {
+            Executor e = new Executor(new DefaultEnvironment());
+            Assert.Equal("nil", e.eval("(find 0 (1 2 3 4))").ToString());
+            Assert.Equal("3", e.eval("(find 3 (1 2 3 4))").ToString());
+        }
     }
 }