drop instruction for saving memory and time

src/interpreter.c

@@ -1468,6 +1468,24 @@ GroundValue interpretGroundInstruction(GroundInstruction inst, GroundScope* scop
             currentInstruction = currentCurrentInstruction;
             break;
         }
+
+        case DROP: {
+            if (in->args.length < 1) {
+                runtimeError(TOO_FEW_ARGS, "Expecting 1 arg", in, currentInstruction);
+            }
+            if (in->args.length > 1) {
+                runtimeError(TOO_MANY_ARGS, "Expecting 1 arg", in, currentInstruction);
+            }
+            if (in->args.args[0].type != DIRREF) {
+                runtimeError(ARG_TYPE_MISMATCH, "Expecting a DirectRef for arg 1", in, currentInstruction);
+            }
+            GroundVariable* var = findVariable(*scope->variables, in->args.args[0].value.refName);
+            if (!var) {
+                runtimeError(UNKNOWN_VARIABLE, NULL, in, currentInstruction);
+            }
+            deleteVariable(scope->variables, var);
+            break;
+        }
         default: {
             runtimeError(FIXME, "Currently unimplemented instruction", in, currentInstruction);
         }

src/parser.c

@@ -169,6 +169,7 @@ static GroundInstType getInstructionType(const char* inst) {
     if (strcmp(inst, "init") == 0) return INIT;
     if (strcmp(inst, "use") == 0) return USE;
     if (strcmp(inst, "extern") == 0) return EXTERN;
+    if (strcmp(inst, "drop") == 0) return DROP;
     if (strcmp(inst, "PAUSE") == 0) return PAUSE;
     
     fprintf(stderr, "Error: Unknown instruction: %s\n", inst);

src/types.c

@@ -371,6 +371,9 @@ void printGroundInstruction(GroundInstruction* gi) {
         case EXTERN:
             printf("extern");
             break;
+        case DROP:
+            printf("drop");
+            break;
         case CREATELABEL:
             break;
         default:

src/types.h

@@ -8,7 +8,7 @@
 #include <string.h>
 
 typedef enum GroundInstType {
-    IF, JUMP, END, INPUT, PRINT, PRINTLN, SET, GETTYPE, EXISTS, SETLIST, SETLISTAT, GETLISTAT, GETLISTSIZE, LISTAPPEND, GETSTRSIZE, GETSTRCHARAT, ADD, SUBTRACT, MULTIPLY, DIVIDE, EQUAL, INEQUAL, NOT, GREATER, LESSER, STOI, STOD, TOSTRING, FUN, RETURN, ENDFUN, PUSHARG, CALL, STRUCT, ENDSTRUCT, INIT, USE, EXTERN, CREATELABEL, PAUSE
+    IF, JUMP, END, INPUT, PRINT, PRINTLN, SET, GETTYPE, EXISTS, SETLIST, SETLISTAT, GETLISTAT, GETLISTSIZE, LISTAPPEND, GETSTRSIZE, GETSTRCHARAT, ADD, SUBTRACT, MULTIPLY, DIVIDE, EQUAL, INEQUAL, NOT, GREATER, LESSER, STOI, STOD, TOSTRING, FUN, RETURN, ENDFUN, PUSHARG, CALL, STRUCT, ENDSTRUCT, INIT, USE, EXTERN, CREATELABEL, PAUSE, DROP
 } GroundInstType;
 
 typedef enum GroundValueType {

tests/drop.grnd

@@ -0,0 +1,4 @@
+set &x "dingus"
+PAUSE
+drop &x
+PAUSE