feat: add blocks and prepare for local variables

Author: aymaneelmaini

Makefile

@@ -9,7 +9,7 @@ TEST_SOURCES = tests/scanner_test.c tests/compiler_test.c
 all: clox
 
 clox: src/main.c $(SOURCES)
-	@$(CC) $(CFLAGS) -o clox src/main.c $(SOURCES) -I.
+	@$(CC) $(CFLAGS) -o clox src/main.c $(SOURCES) -I. && echo Compiled!!!!
 
 run: clox
 	@./clox

src/common.h

@@ -5,6 +5,8 @@
 #include <stddef.h>
 #include <stdint.h>
 
+#define UINT8_COUNT (UINT8_MAX + 1)
+
 typedef uint8_t  u8;
 typedef uint32_t u32;
 

src/compiler.c

@@ -48,8 +48,23 @@ typedef struct
 
 } ParseRule;
 
-Parser parser;
-Chunk* compiling_chunk;
+typedef struct
+{
+    Token name;
+    int   depth;
+} Local;
+
+typedef struct
+{
+    Local locals[UINT8_COUNT];
+    int   local_count;
+    int   local_depth;
+
+} Compiler;
+
+Parser    parser;
+Compiler* current;
+Chunk*    compiling_chunk;
 
 static Chunk* current_chunk()
 {
@@ -93,14 +108,11 @@ static void error_at_current(const char* message)
 static void advance()
 {
     parser.previous = parser.current;
-
     for (;;)
     {
         parser.current = scan_token();
-
         if (parser.current.type != TOKEN_ERROR)
             break;
-
         error_at_current(parser.current.start);
     }
 }
@@ -112,7 +124,6 @@ static void consume(TokenType type, char* message)
         advance();
         return;
     }
-
     error_at_current(message);
 }
 
@@ -125,7 +136,6 @@ static bool match(TokenType type)
 {
     if (!check(type))
         return false;
-
     advance();
     return true;
 }
@@ -149,13 +159,11 @@ static void emit_return()
 static u8 make_constant(Value value)
 {
     int constant = add_constant(current_chunk(), value);
-
     if (constant > UINT8_MAX)
     {
         error("Too many constants in one chunk");
         return 0;
     }
-
     return (u8)constant;
 }
 
@@ -164,6 +172,13 @@ static void emit_constant(Value value)
     emit_bytes(OP_CONSTANT, make_constant(value));
 }
 
+static void init_compiler(Compiler* compiler)
+{
+    compiler->local_count = 0;
+    compiler->local_depth = 0;
+    current = compiler;
+}
+
 static void end_compiler()
 {
     emit_return();
@@ -173,6 +188,16 @@ static void end_compiler()
 #endif
 }
 
+static void begin_scope()
+{
+    current->local_depth++;
+}
+
+static void end_scope()
+{
+    current->local_depth--;
+}
+
 static void       expression();
 static void       statement();
 static void       declaration();
@@ -284,7 +309,9 @@ static void named_variable(Token name, bool can_assign)
         emit_bytes(OP_SET_GLOBAL, arg);
     }
     else
+    {
         emit_bytes(OP_GET_GLOBAL, arg);
+    }
 }
 
 static void variable(bool can_assign)
@@ -392,6 +419,16 @@ static void expression()
 
 // ---------------------- statements --------------------------
 
+static void block()
+{
+    while (!check(TOKEN_RIGHT_BRACE) && !check(TOKEN_EOF))
+    {
+        declaration();
+    }
+
+    consume(TOKEN_RIGHT_BRACE, "Expect '}' after block");
+}
+
 static void var_declaration()
 {
     u8 global = parse_variable("Expect variable name");
@@ -462,9 +499,19 @@ static void declaration()
 static void statement()
 {
     if (match(TOKEN_PRINT))
+    {
         print_statement();
+    }
+    else if (match(TOKEN_LEFT_BRACE))
+    {
+        begin_scope();
+        block();
+        end_scope();
+    }
     else
+    {
         expression_statement();
+    }
 }
 
 static inline void init_parser()
@@ -476,6 +523,8 @@ static inline void init_parser()
 bool compile(const char* source, Chunk* chunk)
 {
     init_scanner(source);
+    Compiler compiler;
+    init_compiler(&compiler);
     compiling_chunk = chunk;
     init_parser();
 

src/main.c

@@ -4,72 +4,14 @@
 
 #include "vm.h"
 
-static void repl()
-{
-    char line[1024];
-
-    for (;;)
-    {
-        printf(">  ");
-        if (!fgets(line, sizeof(line), stdin))
-        {
-            printf("\n");
-            break;
-        }
-        interpret(line);
-    }
-}
-
-static char* read_file(const char* path)
-{
-    FILE* fd = fopen(path, "rb");
-    if (fd == NULL)
-    {
-        fprintf(stderr, "Could not open file %s \n", path);
-        exit(74);
-    }
-
-    fseek(fd, 0L, SEEK_END);
-    size_t fileSize = ftell(fd);
-    rewind(fd);
-
-    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, fd);
-    if (bytesRead < fileSize)
-    {
-        fprintf(stderr, "Could not read file %s \n", path);
-        exit(74);
-    }
-
-    buffer[bytesRead] = '\0';
-
-    fclose(fd);
-
-    return buffer;
-}
+static void repl();
+static char* read_file(const char* path);
+static void run_file(const char* path);
 
-static void run_file(const char* path)
-{
-    char*           source = read_file(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[])
 {
     init_VM();
-
     if (argc == 1)
         repl();
     else if (argc == 2)
@@ -79,7 +21,62 @@ int main(int argc, const char* argv[])
         fprintf(stderr, "Usage: clox [path]\n");
         exit(64);
     }
-
     free_VM();
     return 0;
 }
+
+static void repl()
+{
+  char line[1024];
+  for (;;)
+  {
+    printf(">  ");
+    if (!fgets(line, sizeof(line), stdin))
+    {
+      printf("\n");
+      break;
+    }
+    interpret(line);
+  }
+}
+
+static char* read_file(const char* path)
+{
+  FILE* fd = fopen(path, "rb");
+  if (fd == NULL)
+  {
+    fprintf(stderr, "Could not open file %s \n", path);
+    exit(74);
+  }
+  fseek(fd, 0L, SEEK_END);
+  size_t fileSize = ftell(fd);
+  rewind(fd);
+
+  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, fd);
+  if (bytesRead < fileSize)
+  {
+    fprintf(stderr, "Could not read file %s \n", path);
+    exit(74);
+  }
+  buffer[bytesRead] = '\0';
+  fclose(fd);
+  return buffer;
+}
+
+static void run_file(const char* path)
+{
+  char*           source = read_file(path);
+  InterpretResult result = interpret(source);
+  free(source);
+
+  if (result == INTERPRET_COMPILE_ERROR)
+    exit(65);
+  if (result == INTERPRET_RUNTIME_ERROR)
+    exit(70);
+}