diff --git a/chunk.h b/chunk.h
index 0be5109..e070155 100644
--- a/chunk.h
+++ b/chunk.h
@@ -6,7 +6,7 @@
 
 typedef enum {
   OP_ARRAY, OP_CONSTANT, OP_CONSTANT_LONG, OP_HASH, OP_NIL, OP_TRUE, OP_FALSE,
-  OP_POP, OP_GET_LOCAL, OP_GET_LOCAL_LONG, OP_INDEX, OP_SET_LOCAL,
+  OP_POP, OP_GET_LOCAL, OP_GET_LOCAL_LONG, OP_INDEX, OP_INDEX_FLIPPED, OP_SET_INDEX, OP_SET_LOCAL,
   OP_SET_LOCAL_LONG, OP_GET_GLOBAL, OP_GET_GLOBAL_LONG, OP_DEFINE_GLOBAL,
   OP_SET_GLOBAL, OP_SET_GLOBAL_LONG, OP_DEFINE_GLOBAL_LONG, OP_EQUAL,
   OP_GREATER, OP_LESS, OP_ADD, OP_SUBTRACT, OP_MULTIPLY, OP_DIVIDE, OP_NOT,
diff --git a/compiler.c b/compiler.c
index aca0554..1d24ad0 100644
--- a/compiler.c
+++ b/compiler.c
@@ -364,8 +364,18 @@ static void declareVariable() {
   addLocal(*name);
 }
 
+static void compiler_index(bool canAssign) {
+  expression();
+  emitByte(OP_INDEX);
+  if (check(TOKEN_COMMA)) {
+    errorAtCurrent("Cannot get multiple values at once");
+  }
+  consume(TOKEN_RIGHT_BRACKET, "Unterminated index");
+}
+
 static void namedVariable(Token name, bool canAssign) {
   uint8_t getOp, getLongOp, setOp, setLongOp;
+  bool indexed = false;
   int arg = resolveLocal(current, &name);
   if (arg != -1) {
     getOp = OP_GET_LOCAL;
@@ -379,10 +389,24 @@ static void namedVariable(Token name, bool canAssign) {
     setOp = OP_SET_GLOBAL;
     setLongOp = OP_SET_GLOBAL_LONG;
   }
-
+  if (canAssign && match(TOKEN_LEFT_BRACKET)) {
+    expression();
+    consume(TOKEN_RIGHT_BRACKET, "Unterminated index");
+    indexed = true;
+  }
   if (canAssign && match(TOKEN_EQUAL)) {
     expression();
-    if (arg < 256) {
+    if (indexed) {
+      if (arg < 256) {
+        emitBytes(getOp, arg);
+      } else {
+        emitByte(getLongOp);
+        emitByte(arg & 0xFF0000 >> 16);
+        emitByte(arg & 0xFF00 >> 8);
+        emitByte(arg & 0xFF);
+      }
+      emitByte(OP_SET_INDEX);
+    } else if (arg < 256) {
       emitBytes(setOp, arg);
     } else {
       emitByte(setLongOp);
@@ -399,6 +423,9 @@ static void namedVariable(Token name, bool canAssign) {
       emitByte(arg & 0xFF00 >> 8);
       emitByte(arg & 0xFF);
     }
+    if (indexed) {
+      emitByte(OP_INDEX_FLIPPED);
+    }
   }
 }
 
@@ -415,7 +442,7 @@ static void and_(bool canAssign) {
   patchJump(endJump);
 }
 
-static void array_unary(bool canAssign) {
+static void array(bool canAssign) {
   expression();
   if (check(TOKEN_COMMA)) {
     int numValues = 0;
@@ -430,23 +457,13 @@ static void array_unary(bool canAssign) {
     emitByte(OP_ARRAY);
     emitByte(numValues + 1);
   } else {
-    expression();
     emitByte(OP_ARRAY);
     emitByte(1);
   }
   consume(TOKEN_RIGHT_BRACKET, "Unterminated array");
 }
 
-static void compiler_index(bool canAssign) {
-  expression();
-  emitByte(OP_INDEX);
-  if (check(TOKEN_COMMA)) {
-    errorAtCurrent("Cannot get multiple values at once");
-  }
-  consume(TOKEN_RIGHT_BRACKET, "Unterminated index");
-}
-
-static void hash_unary(bool canAssign) {
+static void hash(bool canAssign) {
   expression();
   if (check(TOKEN_ROCKET)) {
     int numValues = 0;
@@ -466,6 +483,8 @@ static void hash_unary(bool canAssign) {
     emitByte(OP_HASH);
     emitByte(numValues + 1);
   } else {
+    consume(TOKEN_ROCKET, "=> must follow every key in a hash");
+    expression();
     emitByte(OP_HASH);
     emitByte(1);
   }
@@ -474,9 +493,9 @@ static void hash_unary(bool canAssign) {
 
 ParseRule rules[] = { { grouping, NULL, PREC_CALL },       // TOKEN_LEFT_PAREN
 { NULL, NULL, PREC_NONE },       // TOKEN_RIGHT_PAREN
-{ hash_unary, NULL, PREC_CALL },       // TOKEN_LEFT_BRACE
+{ hash, NULL, PREC_CALL },       // TOKEN_LEFT_BRACE
 { NULL, NULL, PREC_NONE },       // TOKEN_RIGHT_BRACE
-{ array_unary, compiler_index, PREC_CALL },       // TOKEN_LEFT_BRACKET
+{ array, compiler_index, PREC_CALL },       // TOKEN_LEFT_BRACKET
 { NULL, NULL, PREC_NONE },       // TOKEN_RIGHT_BRACKET
 { NULL, NULL, PREC_NONE },       // TOKEN_COMMA
 { NULL, NULL, PREC_CALL },       // TOKEN_DOT
diff --git a/debug.c b/debug.c
index 06892a7..a6e0ba5 100644
--- a/debug.c
+++ b/debug.c
@@ -87,6 +87,10 @@ int disassembleInstruction(Chunk* chunk, int offset) {
     return simpleInstruction("OP_POP", offset);
   case OP_INDEX:
     return simpleInstruction("OP_INDEX", offset);
+  case OP_INDEX_FLIPPED:
+    return simpleInstruction("OP_INDEX_FLIPPED", offset);
+  case OP_SET_INDEX:
+    return simpleInstruction("OP_SET_INDEX", offset);
   case OP_GET_LOCAL:
     return byteInstruction("OP_GET_LOCAL", chunk, offset);
   case OP_SET_LOCAL:
diff --git a/vm.c b/vm.c
index 125cf73..890fad9 100644
--- a/vm.c
+++ b/vm.c
@@ -110,6 +110,62 @@ static inline Value readConstantLong() {
   return vm.chunk->constants.values[constant];
 }
 
+static bool check_array_index(Value index, int* idx) {
+  if (!IS_NUMBER(index)) {
+    runtimeError("Array index must be a non-negative integer.");
+    return false;
+  }
+  double i_double = AS_NUMBER(index);
+  if (i_double < 0) {
+    runtimeError("Array index must be a non-negative integer.");
+    return false;
+  }
+  if ((int) i_double != i_double) {
+    runtimeError("Array index must be a non-negative integer.");
+    return false;
+  }
+  *idx = (int) i_double;
+  return true;
+}
+
+static bool vm_index(Value index, Value val) {
+  if (IS_OBJ(val)) {
+    Obj* obj = AS_OBJ(val);
+    switch (obj->type) {
+    case OBJ_ARRAY: {
+      ValueArray* valArray = AS_VARRAY(val);
+      int i;
+      if (!check_array_index(index, &i)) {
+        return false;
+      }
+      if (i>=valArray->count) {
+        runtimeError("Array index out of bounds");
+        return false;
+      }
+      push(valArray->values[i]);
+      break;
+    }
+    case OBJ_HASH: {
+      Table* hashTable = AS_HASH(val);
+      Value* value = malloc(sizeof(Value));
+      if (tableGet(hashTable, index, value)) {
+        push(*value);
+      } else {
+        push(NIL_VAL);
+      }
+      break;
+    }
+    default:
+      runtimeError("Cannot index value.");
+      return false;
+    }
+  } else {
+    runtimeError("Cannot index value.");
+    return false;
+  }
+  return true;
+}
+
 static InterpretResult run() {
   for (;;) {
 #ifdef DEBUG_TRACE_EXECUTION
@@ -184,40 +240,45 @@ static InterpretResult run() {
     case OP_INDEX: {
       Value index = pop();
       Value val = pop();
+      bool res = vm_index(index, val);
+      if (!res) return INTERPRET_RUNTIME_ERROR;
+      break;
+    }
+    case OP_INDEX_FLIPPED: {
+      Value val = pop();
+      Value index = pop();
+      bool res = vm_index(index, val);
+      if (!res) return INTERPRET_RUNTIME_ERROR;
+      break;
+    }
+    case OP_SET_INDEX: {
+      Value val = pop();
+      Value set_val = pop();
+      Value index = pop();
       if (IS_OBJ(val)) {
         Obj* obj = AS_OBJ(val);
         switch (obj->type) {
         case OBJ_ARRAY: {
           ValueArray* valArray = AS_VARRAY(val);
-          if (!IS_NUMBER(index)) {
-            runtimeError("Array index must be a non-negative integer.");
+          int i;
+          if (!check_array_index(index, &i)) {
+            printf("ERR\n");
             return INTERPRET_RUNTIME_ERROR;
           }
-          double i_double = AS_NUMBER(index);
-          if (i_double < 0) {
-            runtimeError("Array index must be a non-negative integer.");
-            return INTERPRET_RUNTIME_ERROR;
+          if (i>=valArray->count) {
+            int num_nils=i-valArray->count;
+            for (;num_nils>0;num_nils--) {
+              writeValueArray(valArray,NIL_VAL);
+            }
+            writeValueArray(valArray,set_val);
+          } else {
+            valArray->values[i]=set_val;
           }
-          if ((int) i_double != i_double) {
-            runtimeError("Array index must be a non-negative integer.");
-            return INTERPRET_RUNTIME_ERROR;
-          }
-          int i = (int) i_double;
-          if (i > valArray->count - 1) {
-            runtimeError("Array index out of bounds.");
-            return INTERPRET_RUNTIME_ERROR;
-          }
-          push(valArray->values[i]);
           break;
         }
         case OBJ_HASH: {
           Table* hashTable = AS_HASH(val);
-          Value* value = malloc(sizeof(Value));
-          if (tableGet(hashTable, index, value)) {
-            push(*value);
-          } else {
-            push(NIL_VAL);
-          }
+          tableSet(hashTable, index, set_val);
           break;
         }
         default:
@@ -228,6 +289,7 @@ static InterpretResult run() {
         runtimeError("Cannot index value.");
         return INTERPRET_RUNTIME_ERROR;
       }
+      push(set_val);
       break;
     }
     case OP_GET_LOCAL: {
@@ -370,7 +432,7 @@ static InterpretResult run() {
       break;
     }
   }
-  return INTERPRET_RUNTIME_ERROR;
+  return INTERPRET_OK;
 }
 
 InterpretResult interpret(const char* source, bool repl) {