Fixed some error states and error messages, read more

By leaving 'null' on the stack, it won't cause stack underflows in a
bunch of erroneous situations. This will allow the repl (and other
situations) to continue if they want to.

I've also fixed some error messages in toy_table.c, which were formatted
badly.

Closes #162

source/toy_opcodes.h

@@ -45,7 +45,6 @@ typedef enum Toy_OpcodeType {
 	TOY_OPCODE_PRINT,
 	TOY_OPCODE_CONCAT,
 	TOY_OPCODE_INDEX,
-	//URGENT: clear the program stack - much needed
 
 	//meta instructions
 	TOY_OPCODE_PASS,

source/toy_table.c

@@ -58,7 +58,8 @@ Toy_Table* Toy_private_adjustTableCapacity(Toy_Table* oldTable, unsigned int new
 	Toy_Table* newTable = malloc(newCapacity * sizeof(Toy_TableEntry) + sizeof(Toy_Table));
 
 	if (newTable == NULL) {
-		Toy_error(TOY_CC_ERROR "ERROR: Failed to allocate a 'Toy_Table'\n" TOY_CC_RESET);
+		fprintf(stderr, TOY_CC_ERROR "ERROR: Failed to allocate a 'Toy_Table'\n" TOY_CC_RESET);
+		exit(1);
 	}
 
 	newTable->capacity = newCapacity;
@@ -103,7 +104,8 @@ void Toy_freeTable(Toy_Table* table) {
 
 void Toy_insertTable(Toy_Table** tableHandle, Toy_Value key, Toy_Value value) {
 	if (TOY_VALUE_IS_NULL(key) || TOY_VALUE_IS_BOOLEAN(key)) { //TODO: disallow functions and opaques
-		Toy_error(TOY_CC_ERROR "ERROR: Bad table key\n" TOY_CC_RESET);
+		fprintf(stderr, TOY_CC_ERROR "ERROR: Bad table key\n" TOY_CC_RESET);
+		exit(1);
 	}
 
 	//expand the capacity
@@ -116,7 +118,8 @@ void Toy_insertTable(Toy_Table** tableHandle, Toy_Value key, Toy_Value value) {
 
 Toy_TableEntry* Toy_private_lookupTableEntryPtr(Toy_Table** tableHandle, Toy_Value key) {
 	if (TOY_VALUE_IS_NULL(key) || TOY_VALUE_IS_BOOLEAN(key)) { //TODO: disallow functions and opaques
-		Toy_error(TOY_CC_ERROR "ERROR: Bad table key\n" TOY_CC_RESET);
+		fprintf(stderr, TOY_CC_ERROR "ERROR: Bad table key\n" TOY_CC_RESET);
+		exit(1);
 	}
 
 	//lookup
@@ -153,7 +156,8 @@ Toy_Value Toy_lookupTable(Toy_Table** tableHandle, Toy_Value key) {
 
 void Toy_removeTable(Toy_Table** tableHandle, Toy_Value key) {
 	if (TOY_VALUE_IS_NULL(key) || TOY_VALUE_IS_BOOLEAN(key)) { //TODO: disallow functions and opaques
-		Toy_error(TOY_CC_ERROR "ERROR: Bad table key\n" TOY_CC_RESET);
+		fprintf(stderr, TOY_CC_ERROR "ERROR: Bad table key\n" TOY_CC_RESET);
+		exit(1);
 	}
 
 	//lookup

source/toy_vm.c

@@ -81,7 +81,7 @@ static void processRead(Toy_VM* vm) {
 				value = TOY_VALUE_FROM_STRING(Toy_createNameStringLength(&vm->stringBucket, cstring, len, valueType, false));
 			}
 			else {
-				Toy_error("Invalid string type found");
+				Toy_error("Invalid string type found in opcode read");
 			}
 
 			break;
@@ -270,6 +270,7 @@ static void processAssignCompound(Toy_VM* vm) {
 			Toy_freeValue(target);
 			Toy_freeValue(key);
 			Toy_freeValue(value);
+			return;
 		}
 
 		//set the value
@@ -303,6 +304,7 @@ static void processAccess(Toy_VM* vm) {
 
 	//check name string type
 	if (!TOY_VALUE_IS_STRING(name) && TOY_VALUE_AS_STRING(name)->info.type != TOY_STRING_NAME) {
+		Toy_pushStack(&vm->stack, TOY_VALUE_FROM_NULL());
 		Toy_error("Invalid access target");
 		return;
 	}
@@ -312,6 +314,7 @@ static void processAccess(Toy_VM* vm) {
 
 	if (valuePtr == NULL) {
 		Toy_freeValue(name);
+		Toy_pushStack(&vm->stack, TOY_VALUE_FROM_NULL());
 		return;
 	}
 
@@ -352,6 +355,7 @@ static void processArithmetic(Toy_VM* vm, Toy_OpcodeType opcode) {
 
 		Toy_freeValue(left);
 		Toy_freeValue(right);
+		Toy_pushStack(&vm->stack, TOY_VALUE_FROM_NULL());
 		return;
 	}
 
@@ -361,6 +365,7 @@ static void processArithmetic(Toy_VM* vm, Toy_OpcodeType opcode) {
 			Toy_error("Can't divide or modulo by zero");
 			Toy_freeValue(left);
 			Toy_freeValue(right);
+			Toy_pushStack(&vm->stack, TOY_VALUE_FROM_NULL());
 			return;
 		}
 	}
@@ -370,6 +375,7 @@ static void processArithmetic(Toy_VM* vm, Toy_OpcodeType opcode) {
 		Toy_error("Can't modulo by a float");
 		Toy_freeValue(left);
 		Toy_freeValue(right);
+		Toy_pushStack(&vm->stack, TOY_VALUE_FROM_NULL());
 		return;
 	}
 
@@ -443,6 +449,7 @@ static void processComparison(Toy_VM* vm, Toy_OpcodeType opcode) {
 
 		Toy_freeValue(left);
 		Toy_freeValue(right);
+		Toy_pushStack(&vm->stack, TOY_VALUE_FROM_NULL());
 		return;
 	}
 
@@ -608,6 +615,7 @@ static void processConcat(Toy_VM* vm) {
 		Toy_error("Failed to concatenate a value that is not a string");
 		Toy_freeValue(left);
 		Toy_freeValue(right);
+		Toy_pushStack(&vm->stack, TOY_VALUE_FROM_NULL());
 		return;
 	}
 
@@ -634,7 +642,7 @@ static void processIndex(Toy_VM* vm) {
 	}
 	else {
 		Toy_error("Incorrect number of elements found in index");
-		//TODO: clear stack, then leave null
+		Toy_pushStack(&vm->stack, TOY_VALUE_FROM_NULL());
 		return;
 	}
 
@@ -646,6 +654,7 @@ static void processIndex(Toy_VM* vm) {
 			Toy_freeValue(value);
 			Toy_freeValue(index);
 			Toy_freeValue(length);
+			Toy_pushStack(&vm->stack, TOY_VALUE_FROM_NULL());
 			return;
 		}
 
@@ -654,6 +663,7 @@ static void processIndex(Toy_VM* vm) {
 			Toy_freeValue(value);
 			Toy_freeValue(index);
 			Toy_freeValue(length);
+			Toy_pushStack(&vm->stack, TOY_VALUE_FROM_NULL());
 			return;
 		}
 
@@ -668,6 +678,7 @@ static void processIndex(Toy_VM* vm) {
 			Toy_freeValue(value);
 			Toy_freeValue(index);
 			Toy_freeValue(length);
+			Toy_pushStack(&vm->stack, TOY_VALUE_FROM_NULL());
 			return;
 		}
 
@@ -700,6 +711,7 @@ static void processIndex(Toy_VM* vm) {
 			Toy_freeValue(value);
 			Toy_freeValue(index);
 			Toy_freeValue(length);
+			Toy_pushStack(&vm->stack, TOY_VALUE_FROM_NULL());
 			return;
 		}
 
@@ -708,6 +720,7 @@ static void processIndex(Toy_VM* vm) {
 			Toy_freeValue(value);
 			Toy_freeValue(index);
 			Toy_freeValue(length);
+			Toy_pushStack(&vm->stack, TOY_VALUE_FROM_NULL());
 			return;
 		}
 
@@ -722,6 +735,7 @@ static void processIndex(Toy_VM* vm) {
 			Toy_freeValue(value);
 			Toy_freeValue(index);
 			Toy_freeValue(length);
+			Toy_pushStack(&vm->stack, TOY_VALUE_FROM_NULL());
 			return;
 		}
 
@@ -742,6 +756,7 @@ static void processIndex(Toy_VM* vm) {
 			Toy_freeValue(value);
 			Toy_freeValue(index);
 			Toy_freeValue(length);
+			Toy_pushStack(&vm->stack, TOY_VALUE_FROM_NULL());
 			return;
 		}
 
@@ -754,6 +769,7 @@ static void processIndex(Toy_VM* vm) {
 			Toy_freeValue(value);
 			Toy_freeValue(index);
 			Toy_freeValue(length);
+			Toy_pushStack(&vm->stack, TOY_VALUE_FROM_NULL());
 			return;
 		}
 

source/toy_vm.h

@@ -39,8 +39,6 @@ typedef struct Toy_VM {
 	//easy access to memory
 	Toy_Bucket* stringBucket; //stores the string literals
 	Toy_Bucket* scopeBucket; //stores the scopes
-
-	//URGENT: panic/failed state flag
 } Toy_VM;
 
 TOY_API void Toy_initVM(Toy_VM* vm);