From b7fba62e9f1f9f7a5a67fd64d4aed55646d1b58e Mon Sep 17 00:00:00 2001
From: Ben Winston
Date: Mon, 22 May 2023 20:12:40 -0400
Subject: runtime type checking

---
 vm.d | 44 +++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 39 insertions(+), 5 deletions(-)

(limited to 'vm.d')

diff --git a/vm.d b/vm.d
index ef6efbf..5b69a23 100644
--- a/vm.d
+++ b/vm.d
@@ -139,7 +139,12 @@ class VM {
     }
 
     bool isString(Value value) {
-        return value.type == ValueType.STRING;
+        return value.type == ValueType.STRING ||
+                value.type == ValueType.TYPE;
+    }
+
+    bool isType(Value value) {
+        return value.type == ValueType.TYPE;
     }
 
     bool isBoolean(Value value) {
@@ -159,7 +164,11 @@ class VM {
     }
 
     string asString(Value value) {
-        return value.as.str;
+        if (value.type == ValueType.TYPE) {
+            return value.as.type;
+        } else {
+            return value.as.str;
+        }
     }
 
     bool asBoolean(Value value) {
@@ -292,47 +301,71 @@ class VM {
                     double val = asNumber(popA());
                     pushA(makeNumberValue(val * -1));
                     break;
+                case OpCode.OP_TYPE_CHECK_NUMBER:
+                    if (!isNumber(peekA(0))) {
+                        writeln("VM type check: not a number!");
+                        return InterpretResult.RUNTIME_ERROR; // TODO error
+                    }
+                    break;
+                case OpCode.OP_TYPE_CHECK_BOOLEAN:
+                    if (!isBoolean(peekA(0))) {
+                        writeln("VM type check: not a boolean!");
+                        return InterpretResult.RUNTIME_ERROR; // TODO error
+                    }
+                    break;
                 case OpCode.OP_ADD:
                     Value b = popA();
+                    /*
                     if (!isNumber(b)) {
                         writeln("b is not a number!");
                         return InterpretResult.RUNTIME_ERROR;  // TODO error
                     }
+                    */
                     Value a = popA();
+                    /*
                     if (!isNumber(a)) {
                         writeln("a is not a number!");
                         return InterpretResult.RUNTIME_ERROR; // TODO error
                     }
+                    */
                     double bnum = asNumber(b);
                     double anum = asNumber(a);
                     pushA(makeNumberValue(anum + bnum));
                     break;
                 case OpCode.OP_SUBTRACT:
                     Value b = popA();
+                    /*
                     if (!isNumber(b)) {
                         writeln("b is not a number!");
                         return InterpretResult.RUNTIME_ERROR;  // TODO error
                     }
+                    */
                     Value a = popA();
+                    /*
                     if (!isNumber(a)) {
                         writeln("a is not a number!");
                         return InterpretResult.RUNTIME_ERROR; // TODO error
                     }
+                    */
                     double bnum = asNumber(b);
                     double anum = asNumber(a);
                     pushA(makeNumberValue(anum - bnum));
                     break;
                 case OpCode.OP_LESS:
                     Value b = popA();
+                    /*
                     if (!isNumber(b)) {
                         writeln("b is not a number!");
                         return InterpretResult.RUNTIME_ERROR;  // TODO error
                     }
+                    */
                     Value a = popA();
+                    /*
                     if (!isNumber(a)) {
                         writeln("a is not a number!");
                         return InterpretResult.RUNTIME_ERROR; // TODO error
                     }
+                    */
                     double bnum = asNumber(b);
                     double anum = asNumber(a);
                     pushA(makeBooleanValue(anum < bnum));
@@ -342,10 +375,7 @@ class VM {
                     Value ret = popA();
                     popA();  // function
                     this.frameCount--;
-                    //writefln("frameCount: %d", frameCount);
-                    //if (this.frameCount == 0) {
                     if (this.frameCount == 1) {
-                        popA();
                         writefln("returned %s", printableValue(ret));
                         return InterpretResult.OK;
                     }
@@ -387,10 +417,12 @@ class VM {
                     break;
                 case OpCode.OP_JUMP_IF_TRUE:
                     uint offset = readShort();
+                    /*
                     if (!isBoolean(peekA(0))) {
                         writeln("expecting a boolean condition");
                         return InterpretResult.RUNTIME_ERROR; // TODO error
                     }
+                    */
                     if (asBoolean(peekA(0))) {
                         current.ip += offset;
                     }
@@ -432,6 +464,8 @@ InterpretResult interpret(string source) {
 
     VM vm = new VM();
 
+//    vm.globals[":int"] = makeTypeValue(":int");
+
     vm.pushA(makeObjValue(func));
     CallFrame frame = { func, 0, vm.bStack, 0 };
     vm.pushFrame(frame);
-- 
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