とりあえず構文木を一部作るようにして計算させた

SMILEBASIC/node.d

@@ -3,7 +3,7 @@ import otya.smilebasic.type;
 import otya.smilebasic.token;
 enum NodeType
 {
-    Node = 0b1,
+    Node,
     Expression,
     Constant,
     BinaryOperator,
@@ -20,6 +20,7 @@ class Constant : Expression
     Value value;
     this(Value v)
     {
+        this.type = NodeType.Constant;
         this.value = v;
     }
 }
@@ -28,6 +29,12 @@ class BinaryOperator : Expression
     Expression item1;
     TokenType operator;
     Expression item2;
+    this(Expression i1, TokenType o)
+    {
+        this.type = NodeType.BinaryOperator;
+        this.item1 = i1;
+        this.operator = o;
+    }
     this(Expression i1, TokenType o, Expression i2)
     {
         this.type = NodeType.BinaryOperator;