Chapter 16.1

clox/src/CMakeLists.txt

@@ -10,6 +10,10 @@ add_executable(Lox
   value.c
   vm.h
   vm.c
+  compiler.h
+  compiler.c
+  scanner.h
+  scanner.c
   main.c)
 
 install(TARGETS Lox)

clox/src/compiler.c

@@ -0,0 +1,7 @@
+#include <stdio.h>
+
+#include "common.h"
+#include "compiler.h"
+#include "scanner.h"
+
+void compile(const char *source) { initScanner(source); }

clox/src/compiler.h

@@ -0,0 +1,6 @@
+#ifndef COMPILER_H
+#define COMPILER_H
+
+void compile(const char *source);
+
+#endif

clox/src/main.c

@@ -1,36 +1,78 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
 #include "chunk.h"
 #include "common.h"
 #include "debug.h"
 #include "vm.h"
 
+static void repl() {
+  char line[1024];
+  for (;;) {
+    printf("> ");
+
+    if (!fgets(line, sizeof(line), stdin)) {
+      printf("\n");
+      break;
+    }
+
+    interpret(line);
+  }
+}
+
+static char *readFile(const char *path) {
+  FILE *file = fopen(path, "rb");
+  if (file == NULL) {
+    fprintf(stderr, "Could not open file \"%s\".\n", path);
+    exit(74);
+  }
+
+  fseek(file, 0L, SEEK_END);
+  size_t fileSize = ftell(file);
+  rewind(file);
+
+  char *buffer = (char *)malloc(fileSize + 1);
+  if (buffer == NULL) {
+    fprintf(stderr, "Not enough memory to read \"%s\".\n", path);
+    exit(74);
+  }
+
+  size_t bytesRead = fread(buffer, sizeof(char), fileSize, file);
+  if (bytesRead < fileSize) {
+    fprintf(stderr, "Could not read file \"%s\".\n", path);
+    exit(74);
+  }
+
+  buffer[bytesRead] = '\0';
+
+  fclose(file);
+  return buffer;
+}
+
+static void runFile(const char *path) {
+  char *source = readFile(path);
+  InterpretResult result = interpret(source);
+  free(source);
+
+  if (result == INTERPRET_COMPILE_ERROR)
+    exit(65);
+  if (result == INTERPRET_RUNTIME_ERROR)
+    exit(70);
+}
+
 int main(int argc, const char *argv[]) {
   initVM();
 
-  Chunk chunk;
-  initChunk(&chunk);
+  if (argc == 1) {
+    repl();
+  } else if (argc = 2) {
+    runFile(argv[1]);
+  } else {
+    fprintf(stderr, "Usage: clox [path]\n");
+    exit(64);
+  }
 
-  int constant = addConstant(&chunk, 1.2);
-  writeChunk(&chunk, OP_CONSTANT, 123);
-  writeChunk(&chunk, constant, 123);
-
-  constant = addConstant(&chunk, 3.4);
-  writeChunk(&chunk, OP_CONSTANT, 123);
-  writeChunk(&chunk, constant, 123);
-
-  writeChunk(&chunk, OP_ADD, 123);
-
-  constant = addConstant(&chunk, 5.6);
-  writeChunk(&chunk, OP_CONSTANT, 123);
-  writeChunk(&chunk, constant, 123);
-
-  writeChunk(&chunk, OP_DIVIDE, 123);
-  writeChunk(&chunk, OP_NEGATE, 123);
-
-  writeChunk(&chunk, OP_RETURN, 123);
-
-  disassembleChunk(&chunk, "test chunk");
-  interpret(&chunk);
   freeVM();
-  freeChunk(&chunk);
   return 0;
 }

clox/src/scanner.c

@@ -0,0 +1,19 @@
+#include <stdio.h>
+#include <string.h>
+
+#include "common.h"
+#include "scanner.h"
+
+typedef struct {
+  const char *start;
+  const char *current;
+  int line;
+} Scanner;
+
+Scanner scanner;
+
+void initScanner(const char *source) {
+  scanner.start = source;
+  scanner.current = source;
+  scanner.line = 1;
+}

clox/src/scanner.h

@@ -0,0 +1,6 @@
+#ifndef SCANNER_H
+#define SCANNER_H
+
+void initScanner(const char *source);
+
+#endif

clox/src/vm.c

@@ -1,6 +1,7 @@
 #include <stdio.h>
 
 #include "common.h"
+#include "compiler.h"
 #include "debug.h"
 #include "vm.h"
 
@@ -79,8 +80,7 @@ static InterpretResult run() {
 #undef BINARY_OP
 }
 
-InterpretResult interpret(Chunk *chunk) {
-  vm.chunk = chunk;
-  vm.ip = vm.chunk->code;
-  return run();
+InterpretResult interpret(const char *source) {
+  compile(source);
+  return INTERPRET_OK;
 }

clox/src/vm.h

@@ -10,7 +10,7 @@ typedef struct {
   Chunk *chunk;
   uint8_t *ip;
   Value stack[STACK_MAX];
-  Value* stackTop;
+  Value *stackTop;
 } VM;
 
 typedef enum {
@@ -21,7 +21,7 @@ typedef enum {
 
 void initVM();
 void freeVM();
-InterpretResult interpret(Chunk *chunk);
+InterpretResult interpret(const char *source);
 void push(Value value);
 Value pop();