1 files changed, 37 insertions, 3 deletions

diff --git a/vm.d b/vm.d
index 2f6de06..d2968a3 100644
--- a/vm.d
+++ b/vm.d
@@ -155,6 +155,10 @@ class VM {
         return value.type == ValueType.OBJ;
     }
 
+    bool isList(Value value) {
+        return isObj(value) && objTypeOf(value) == ObjType.LIST;
+    }
+
     ObjType objTypeOf(Value value) {
         return value.as.obj.type;
     }
@@ -220,7 +224,6 @@ class VM {
     InterpretResult run() {
         writeln("== VM running ==");
         while (true) {
-            /*
             writeln("          Stacks:");
             write("          A> ");
             for (int i = 0; i < aTop; i++) {
@@ -231,8 +234,12 @@ class VM {
                 //writef("[ %s ]", printableValue(bStack[i]));
                 writef("[ %s ]", printableValue(current.slots[i]));
             }
+
+            write("\n constants>  ");
+            for (int i = 0; i < current.func.chunk.constants.length; i++) {
+                writef("[ %s ]", printableValue(current.func.chunk.constants[i]));
+            }
             writeln("\n--");
-            */
 
             /*
             write(" globals >");
@@ -243,7 +250,7 @@ class VM {
             writeln("\n--");
             */
 
-            //disassemble(current.func.chunk, current.ip);
+            disassemble(current.func.chunk, current.ip);
             ubyte inst;
             switch (inst = this.readByte()) {
                 case OpCode.OP_DEF_GLOBAL:
@@ -301,6 +308,18 @@ class VM {
                     double val = asNumber(popA());
                     pushA(makeNumberValue(val * -1));
                     break;
+                case OpCode.OP_TYPE_CHECK_LIST:
+                    if (!isList(peekA(0))) {
+                        writeln("VM type check: not a list!");
+                        return InterpretResult.RUNTIME_ERROR; // TODO error
+                    }
+                    break;
+                case OpCode.OP_TYPE_CHECK_STRING:
+                    if (!isString(peekA(0))) {
+                        writeln("VM type check: not a string!");
+                        return InterpretResult.RUNTIME_ERROR; // TODO error
+                    }
+                    break;
                 case OpCode.OP_TYPE_CHECK_NUMBER:
                     if (!isNumber(peekA(0))) {
                         writeln("VM type check: not a number!");
@@ -313,6 +332,14 @@ class VM {
                         return InterpretResult.RUNTIME_ERROR; // TODO error
                     }
                     break;
+                case OpCode.OP_FIRST:
+                    Value val = popA();
+                    List lst = cast(List)val.as.obj;  // TODO this needs better checking
+                    int addr = lst.first();
+                    writefln("got this address: %d", addr);
+                    Value first = current.func.chunk.constants[to!ubyte(addr)];
+                    pushA(first);
+                    break;
                 case OpCode.OP_ADD:
                     Value b = popA();
                     /*
@@ -356,6 +383,13 @@ class VM {
                     bool bval = asBoolean(val);
                     pushA(makeBooleanValue(!bval));
                     break;
+                case OpCode.OP_CONCAT:
+                    Value b = popA();
+                    Value a = popA();
+                    string bstr = asString(b);
+                    string astr = asString(a);
+                    pushA(makeStringValue(astr ~ bstr));
+                    break;
                 case OpCode.OP_GREATER:
                     Value b = popA();
                     Value a = popA();