GOSUB実�

SMILEBASIC/VM.d

@@ -32,7 +32,7 @@ class VM
     this(Code[] code, int len, int[wstring] globalTable)
     {
         this.code = code;
-        this.stack = new Value[1024 * 1024];
+        this.stack = new Value[16384];
         this.global = new Value[len];
         this.globalTable = globalTable;
         foreach(wstring k, int v ; globalTable)
@@ -68,6 +68,10 @@ class VM
     {
         return global[globalTable[name]];
     }
+    void end()
+    {
+        pc = code.length;
+    }
 }
 enum CodeType
 {
@@ -82,6 +86,8 @@ enum CodeType
     GotoS,
     GotoFalse,
     GotoTrue,
+    GosubS,
+    ReturnSubroutine,
 }
 abstract class Code
 {
@@ -420,7 +426,60 @@ class GotoFalse : Code
             vm.pc = address - 1;
     }
 }
-class Gosub : Code
+class GosubAddr : Code
 {
-
+    int address;
+    this(int addr)
+    {
+        this.type = CodeType.Gosub;
+        address = addr;
+    }
+    override void execute(VM vm)
+    {
+        vm.push(Value(vm.pc));
+        vm.pc = address - 1;
+    }
 }
+class GosubS : Code
+{
+    wstring label;
+    this(wstring label)
+    {
+        this.type = CodeType.GosubS;
+        this.label = label;
+    }
+    override void execute(VM vm)
+    {
+        stderr.writeln("can't execute");
+    }
+}
+class ReturnSubroutine : Code
+{
+    this()
+    {
+        this.type = CodeType.ReturnSubroutine;
+    }
+    override void execute(VM vm)
+    {
+        Value pc;
+        vm.pop(pc);
+        if(pc.type != ValueType.Integer || pc.integerValue < 0 || pc.integerValue >= vm.code.length)
+        {
+            stderr.writeln("Internal error:Compiler bug?");
+            readln();
+            return;
+        }
+        vm.pc = pc.integerValue;
+    }
+}
+class EndVM : Code
+{
+    this()
+    {
+    }
+    override void execute(VM vm)
+    {
+        vm.end();
+    }
+}    
+

SMILEBASIC/compiler.d

@@ -42,6 +42,10 @@ class Compiler
     {
         code ~= new GotoS(label);
     }
+    void genCodeGosub(wstring label)
+    {
+        code ~= new GosubS(label);
+    }
     GotoAddr genCodeGoto()
     {
         auto c = new GotoAddr(-1);
@@ -258,6 +262,26 @@ class Compiler
             case NodeType.For:
                 compileFor(cast(For)i);
                 break;
+            case NodeType.Gosub:
+                {
+                    auto gosub = cast(Gosub)i;
+                    genCodeGosub(gosub.label);
+                }
+                break;
+            case NodeType.Return:
+                {
+                    auto ret = cast(Return)i;
+                    if(ret.expression is null)
+                        genCode(new ReturnSubroutine());
+                    else
+                    {
+                        //関数未実装:error
+                    }
+                }
+                break;
+            case NodeType.End:
+                genCode(new EndVM());
+                break;
             default:
                 stderr.writeln("Compile:NotImpl ", i.type);
         }
@@ -274,6 +298,10 @@ class Compiler
             {
                 code[i] = new GotoAddr(globalLabel[(cast(GotoS)c).label]);
             }
+            if(c.type == CodeType.GosubS)
+            {
+                code[i] = new GosubAddr(globalLabel[(cast(GosubS)c).label]);
+            }
         }
         return new VM(code, globalIndex + 1, global);
     }

SMILEBASIC/main.d

@@ -44,7 +44,12 @@ FOR I=0 TO 100
   ENDIF
  ENDIF
 NEXT
-?NOT 1,!!\"a\"
+?@HELLOWORLD
+GOSUB @A
+END
+@A
+?\"SUBROUTINE TEST\"
+RETURN
 ");
     version(none) auto parser = new Parser(readText("FIZZBUZZ.TXT").to!wstring);
     auto vm = parser.compile();

SMILEBASIC/node.d

@@ -23,6 +23,9 @@ enum NodeType
     Goto,
     If,
     For,
+    Gosub,
+    Return,
+    End,
 }
 abstract class Node
 {
@@ -245,3 +248,29 @@ class For : Statement
         this.statements = statements;
     }
 }
+class Gosub : Statement
+{
+    wstring label;
+    this(wstring name)
+    {
+        this.type = NodeType.Gosub;
+        this.label = name;
+    }
+}
+class Return : Statement
+{
+    Expression expression;
+    this(Expression expression)
+    {
+        this.type = NodeType.Return;
+        this.expression = expression;
+    }
+}
+class End : Statement
+{
+    this()
+    {
+        this.type = NodeType.End;
+    }
+}
+

SMILEBASIC/parser.d

@@ -49,6 +49,9 @@ class Lexical
         reserved["FOR"] = TokenType.For;
         reserved["NEXT"] = TokenType.Next;
         reserved["MOD"] = TokenType.Mod;
+        reserved["GOSUB"] = TokenType.Gosub;
+        reserved["RETURN"] = TokenType.Return;
+        reserved["END"] = TokenType.End;
         reserved.rehash();
         line = 1;
     }
@@ -472,7 +475,24 @@ class Parser
             case TokenType.Goto:
                 lex.popFront();
                 token = lex.front();
-                node = new Goto(token.value.stringValue);
+                if(token.type == TokenType.Label)
+                    node = new Goto(token.value.stringValue);
+                else
+                {
+                    writeln("NotImpl");
+                    syntaxError();
+                }
+                break;
+            case TokenType.Gosub:
+                lex.popFront();
+                token = lex.front();
+                if(token.type == TokenType.Label)
+                    node = new Gosub(token.value.stringValue);
+                else
+                {
+                    writeln("NotImpl");
+                    syntaxError();
+                }
                 break;
             case TokenType.If:
                 node = if_();
@@ -480,6 +500,13 @@ class Parser
             case TokenType.For:
                 node = forStatement();
                 break;
+            case TokenType.Return:
+                lex.popFront();
+                node = new Return(expression());
+                return node;
+            case TokenType.End:
+                node = new End();
+                break;
             default:
                 syntaxError();
                 break;
@@ -741,7 +768,7 @@ class Parser
                 break;
             case TokenType.Label://3.1
                 //文字列リテラル
-
+                node = new Constant(token.value);
                 break;
             case TokenType.Minus:
                 //TODO:UnaryOperatorの実装

SMILEBASIC/token.d

@@ -44,6 +44,9 @@ enum TokenType
     LogicalAnd,//&&
     LogicalOr,//||
     IntDiv,//DIV
+    Gosub,
+    Return,
+    End,
 }
 
 struct Token