fix: allow programs to not be a list.

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

@@ -78,7 +78,10 @@ namespace Jellyfin.Plugin.SmartPlaylist.Lisp.Compiler {
                 }
                 value += t;
             }
-            return null;
+            if (value.Equals("")) {
+                return null;
+            }
+            return new AtomToken(value);
         }
     }
 
@@ -101,7 +104,7 @@ namespace Jellyfin.Plugin.SmartPlaylist.Lisp.Compiler {
                 if (prev_avail == program.Available() && prev_avail == 0) {
                     break;
                 } else if (prev_avail == program.Available()) {
-                    throw new ApplicationException("Program is invalid");
+                    throw new ApplicationException($"Program is invalid, still available: {program.Available()}");
                 }
                 prev_avail = program.Available();
                 foreach (Type c in _classes) {

Jellyfin.Plugin.SmartPlaylist/Lisp/Expression.cs

@@ -243,6 +243,13 @@ namespace Jellyfin.Plugin.SmartPlaylist.Lisp {
             return $"{Item1} . {Item2}";
         }
         public override string? ToString() {
+            if (Item1 is Symbol SymbolItem1
+                    && SymbolItem1.Name() == "quote"
+                    && Item2 is Cons ConsItem2
+                    && ConsItem2.Item2.Equals(Boolean.FALSE)
+                    ) {
+                return $"'{ConsItem2.Item1}";
+            }
             return $"({ToStringSimple()})";
         }
     }

Tests/Tests.cs

@@ -70,7 +70,7 @@ namespace Tests
             program = "(abc '(1 2 3))";
             sts = StringTokenStream.generate(program);
             p = new Parser(sts);
-            Assert.Equal("(abc (quote (1 2 3)))", string.Format("{0}", p.parse()));
+            Assert.Equal(program, string.Format("{0}", p.parse()));
 
             program = "(abc \"'(1 2 3)\")";
             sts = StringTokenStream.generate(program);
@@ -148,6 +148,7 @@ namespace Tests
                     (if (> 0 1) (car (quote (1 2 3))) (cdr (quote (2 3 4)))))
             """).ToString());
 
+            Assert.Equal("a", e.eval("'a").ToString());
         }
 
         [Fact]