Data commit

Task/Execute-Brain-/Objeck/execute-brain-.objeck

@@ -0,0 +1,70 @@
+class Brainfu_k {
+  @program : String; @mem : Int[];
+  @ip : Int;  @dp : Int;
+
+  New(program : String, size : Int) {
+    @program := program;
+    @mem := Int → New[size];
+  }
+
+  function : Main(args : String[]) ~ Nil {
+    if(args → Size() = 2) {
+      Brainfu_k → New(args[0], args[1] → ToInt()) → Execute();
+    };
+  }
+
+  method : Execute() ~ Nil {
+    while(@ip < @program → Size()) {
+      instr := @program → Get(@ip);
+      select(instr) {
+        label '>': { @dp += 1; }
+        label '<': { @dp -= 1; }
+        label '+': { @mem[@dp] := @mem[@dp] + 1; }
+        label '-': { @mem[@dp] := @mem[@dp] - 1; }
+        label '.': { value := @mem[@dp] → As(Char); value → Print(); }
+        label ',': { @mem[@dp] := Read(); }
+        label '[': { JumpForward(); }
+        label ']': { JumpBack(); }
+      };
+      @ip += 1;
+    };
+  }
+
+  method : JumpForward() ~ Nil {
+    depth := 1;
+    if(@mem[@dp] = 0) {
+      while(@ip < @program → Size()) {
+        instr := @program → Get(@ip);
+        if(instr = ']') {
+          depth -= 1;  if(depth = 0) { return;  };
+        }
+        else if(instr = '[') { depth += 1; };
+        @ip += 1;
+      };
+      "*** Unbalanced jump ***" → ErrorLine();
+      Runtime → Exit(1);
+    };
+  }
+
+  method : JumpBack() ~ Nil {
+    depth := 1;
+    if(@mem[@dp] <> 0) {
+      while(@ip > 0) {
+        @ip -= 1;
+        instr := @program → Get(@ip);
+        if(instr = '[') {
+          depth -= 1;  if(depth = 0) { return; };
+        }
+        else if(instr = ']') { depth += 1; };
+      };
+      "*** Unbalanced jump ***" → ErrorLine();
+      Runtime → Exit(1);
+    };
+  }
+
+  method : Read() ~ Int {
+    in := IO.Console → ReadString();
+    if(in → Size() > 0) { return in → ToInt(); };
+    return 0;
+  }
+}