Finish Chapter 15

Implement a basic VM that is capable of simple math.

Signed-off-by: Daniel Henry <iamdanhenry@gmail.com>

include/vm.h

@@ -0,0 +1,28 @@
+#ifndef clox_vm_h
+#define clox_vm_h
+
+#include "chunk.h"
+
+#define STACK_MAX 256
+
+typedef struct {
+  Chunk *chunk;
+  uint8_t *ip;
+  Value stack[STACK_MAX];
+  Value *stackTop;
+} VM;
+
+typedef enum {
+  INTERPRET_OK,
+  INTERPRET_COMPILE_ERROR,
+  INTERPRET_RUNTIME_ERROR
+} InterpretResult;
+
+void initVM();
+void freeVM();
+
+InterpretResult interpret(Chunk *chunk);
+void push(Value value);
+Value pop();
+
+#endif /* clox_vm_h */