2 files changed, 56 insertions, 9 deletions

diff --git a/example.tsl b/example.tsl
index e868f77..5146713 100644
--- a/example.tsl
+++ b/example.tsl
@@ -37,6 +37,24 @@ value5 = ["hello", "world", 5]
 # setv "list_index_value"
 list_index_value = value5[0]
 
+# loadn 1
+# loadn 2
+# list 2
+# setv "list1"
+list1 = [1, 2]
+
+# loadn 3
+# loadn 4
+# list 2
+# setv "list2"
+list2 = [3, 4]
+
+# loadv "list1"
+# loadv "list2"
+# add
+# setv "list3"
+list3 = list1 + list2
+
 # loads "hello"
 # loads "world"
 # loads "value"
diff --git a/src/program.c b/src/program.c
index 2f0a9df..3be7c67 100644
--- a/src/program.c
+++ b/src/program.c
@@ -235,6 +235,41 @@ static TslProgramResult tsl_value_create_from_stack_value(TslProgram *self, TslS
     return TSL_PROGRAM_RESULT_OK;
 }
 
+static TslProgramResult tsl_program_perform_operation(TslProgram *self, TslNumber(*operation_func)(TslNumber lhs, TslNumber rhs)) {
+    TslStackValue *args = tsl_buffer_pop(&self->stack_values, sizeof(TslStackValue) * 2);
+    TslValue lhs_value;
+    TslValue rhs_value;
+    TslStackValue stack_value;
+
+    return_if_error(tsl_value_create_from_stack_value(self, args + 1, &rhs_value));
+    return_if_error(tsl_value_create_from_stack_value(self, args, &lhs_value));
+
+    if(lhs_value.type != TSL_TYPE_NUMBER) {
+        fprintf(stderr, "Error: Unable to perform operation '+' between a TODO and a TODO\n");
+        return TSL_PROGRAM_RESULT_ERR;
+    }
+    if(rhs_value.type != TSL_TYPE_NUMBER) {
+        fprintf(stderr, "Error: Unable to perform operation '+' between a TODO and a TODO\n");
+        return TSL_PROGRAM_RESULT_ERR;
+    }
+
+    stack_value.data.number = operation_func(lhs_value.data.number, rhs_value.data.number);
+    stack_value.type = TSL_STACK_VALUE_TYPE_NUMBER;
+    return tsl_buffer_append(&self->stack_values, &stack_value, sizeof(stack_value));
+}
+
+static TslNumber number_operation_sub(TslNumber lhs, TslNumber rhs) {
+    return lhs + rhs;
+}
+
+static TslNumber number_operation_mul(TslNumber lhs, TslNumber rhs) {
+    return lhs * rhs;
+}
+
+static TslNumber number_operation_div(TslNumber lhs, TslNumber rhs) {
+    return lhs / rhs;
+}
+
 TslProgramResult tsl_program_run(TslProgram *self) {
     TslProgramResult result = TSL_PROGRAM_RESULT_OK;
     TslBytecode *file_scope_bytecode = tsl_buffer_begin(&self->function_bytecode_list);
@@ -379,25 +414,19 @@ TslProgramResult tsl_program_run(TslProgram *self) {
                 break;
             }
             case TSL_OPCODE_SUB: {
-                TslStackValue *args = tsl_buffer_pop(&self->stack_values, sizeof(TslStackValue) * 2);
-                (void)args;
-                /* TODO: Implement this */
+                cleanup_if_error(tsl_program_perform_operation(self, number_operation_sub));
                 printf("sub\n");
                 instruction += sizeof(TslInstructionType5);
                 break;
             }
             case TSL_OPCODE_MUL: {
-                TslStackValue *args = tsl_buffer_pop(&self->stack_values, sizeof(TslStackValue) * 2);
-                (void)args;
-                /* TODO: Implement this */
+                cleanup_if_error(tsl_program_perform_operation(self, number_operation_mul));
                 printf("mul\n");
                 instruction += sizeof(TslInstructionType5);
                 break;
             }
             case TSL_OPCODE_DIV: {
-                TslStackValue *args = tsl_buffer_pop(&self->stack_values, sizeof(TslStackValue) * 2);
-                (void)args;
-                /* TODO: Implement this */
+                cleanup_if_error(tsl_program_perform_operation(self, number_operation_div));
                 printf("div\n");
                 instruction += sizeof(TslInstructionType5);
                 break;