lab17: part 4

lab17/compiler.js

@@ -140,12 +140,12 @@ class Compiler {
       // Booleans will be stored as either 1 for true, or as a 0 for false.
       return;
     } else if (ast.type === VAR) {
-      //
-      // ***YOUR CODE HERE***
-      //
       // We look up the offset for a variable and push the offset
       // value on to the stack.  The 'MLOAD' operation will
       // retrieve the value stored at that position in the memory.
+      this.writeOp('PUSH1');
+      this.writeByte(this.varMap[ast.value]);
+      this.writeOp('MLOAD');
       return;
     }
 
@@ -167,9 +167,6 @@ class Compiler {
         break;
 
       case "define":
-        //
-        // ***YOUR CODE HERE***
-        //
         // The define function lets us store variables.
         //
         // The variable name is stored in 'second.value'.
@@ -182,6 +179,14 @@ class Compiler {
         //
         // Increment this.varOffset so that it points to the next
         // position in memory.
+        this.varMap[second.value] = this.varOffset;
+        rest.forEach((x) => {
+          this.writeBytecode(x);
+        });
+        this.writeOp('PUSH1');
+        this.writeByte(this.varOffset);
+        this.writeOp('MSTORE');
+        this.varOffset++;
         break;
 
       case "if":