switching to c++

makefile

@@ -1,26 +1,23 @@
 TARGET := ./target
 SRC := ./src
-CC := clang -c -std=c17 -Wall -Wextra -pedantic -Werror
+CC := clang++ -c -std=c++17 -Wall -Wextra -pedantic -Werror
 
 SRCS := $(shell find $(SRC) -name '*.c')
 OBJS := $(SRCS:%=$(TARGET)/%.o)
 
-$(TARGET)/lox: $(TARGET)/lox.c.o $(TARGET)/parser.c.o $(TARGET)/scanner.c.o $(TARGET)/tokens.c.o $(TARGET)/utils.c.o
-	clang $(TARGET)/lox.c.o -L$(TARGET) -lparser.c.o -ltokens.c.o -lscanner.c.o -lutils.c.o -o $(TARGET)/lox
+$(TARGET)/lox: $(TARGET)/lox.cpp.o $(TARGET)/parser.cpp.o $(TARGET)/scanner.cpp.o
+	clang++ $(TARGET)/lox.cpp.o -L$(TARGET) -lscanner.cpp.o -o $(TARGET)/lox
 
-$(TARGET)/utils.c.o: $(SRC)/utils.c
+$(TARGET)/utils.cpp.o: $(SRC)/utils.cpp
 	$(CC) $< -o $@
 
-$(TARGET)/tokens.c.o: $(SRC)/tokens.c
+$(TARGET)/scanner.cpp.o: $(SRC)/scanner.cpp
 	$(CC) $< -o $@
 
-$(TARGET)/scanner.c.o: $(SRC)/scanner.c
+$(TARGET)/parser.cpp.o: $(SRC)/parser.cpp
 	$(CC) $< -o $@
 
-$(TARGET)/parser.c.o: $(SRC)/parser.c
-	$(CC) $< -o $@
-
-$(TARGET)/lox.c.o: $(SRC)/lox.c $(TARGET)
+$(TARGET)/lox.cpp.o: $(SRC)/lox.cpp $(TARGET)
 	$(CC) $< -o $@
 
 $(TARGET):

src/lox.c

@@ -1,83 +0,0 @@
-#include "scanner.h"
-#include "tokens.h"
-#include "utils.h"
-#include <stdbool.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-
-int run_file(char *file);
-void run_prompt(void);
-ScanResult run(char *source);
-
-int main(int argc, char *argv[]) {
-  if (argc > 2) {
-    puts("Usage: lox [script]");
-    return EXIT_FAILURE;
-  } else if (argc == 2) {
-    return run_file(argv[1]);
-  } else {
-    run_prompt();
-  }
-  return EXIT_SUCCESS;
-}
-
-int run_file(char *filename) {
-
-  FILE *file = fopen(filename, "r");
-  if (file == NULL) {
-    printf("unable to open file '%s'\n", filename);
-    return EXIT_FAILURE;
-  }
-  char line[255];
-
-  char *content = malloc(1);
-  if (content == NULL) {
-    puts("Out of memory");
-    return EXIT_FAILURE;
-  }
-  content[0] = '\0';
-
-  while (fgets(line, sizeof(line), file)) {
-    content = realloc(content, strlen(content) + strlen(line) + 1);
-    if (content == NULL) {
-      return EXIT_FAILURE;
-    }
-    strcat(content, line);
-  }
-
-  fclose(file);
-
-  ScanResult scan_result = run(content);
-
-  // FREE UP
-  free(content);
-
-  if (scan_result.had_error) {
-    return 65;
-  }
-
-  tokenlist_print(&scan_result.token_list);
-
-  return EXIT_SUCCESS;
-}
-
-void run_prompt(void) {
-  char line[255];
-
-  for (;;) {
-    printf(">");
-    char *r = fgets(line, 255, stdin);
-
-    if (r == NULL) {
-      break;
-    }
-
-    int len = (int)strlen(line);
-    ScanResult scan_result = run(substring(line, 1, len - 1));
-
-    tokenlist_print(&scan_result.token_list);
-  }
-}
-
-ScanResult run(char *source) { return scan_tokens(source); }

src/lox.cpp

@@ -0,0 +1,68 @@
+#include "scanner.hpp"
+#include "tokens.hpp"
+#include <cstdbool>
+#include <fstream>
+#include <iostream>
+#include <list>
+#include <string>
+
+void print_tokens(std::list<Token> *list);
+int run_file(std::string file);
+void run_prompt(void);
+ScanResult run(std::string source);
+
+int main(int argc, char *argv[]) {
+  if (argc > 2) {
+    puts("Usage: lox [script]");
+    return EXIT_FAILURE;
+  } else if (argc == 2) {
+    return run_file(argv[1]);
+  } else {
+    run_prompt();
+  }
+  return EXIT_SUCCESS;
+}
+
+int run_file(std::string filename) {
+  std::string content;
+  std::ifstream file;
+  file.open(filename);
+  if (file.is_open()) {
+    file >> content;
+  } else {
+    exit(1);
+  }
+
+  ScanResult scan_result = run(content);
+
+  return EXIT_SUCCESS;
+}
+
+void run_prompt(void) {
+  std::string line;
+
+  for (;;) {
+    std::cout << ">";
+    std::cin >> line;
+
+    ScanResult scan_result = run(line.substr(0, line.length()));
+
+    print_tokens(&scan_result.token_list);
+  }
+}
+
+ScanResult run(std::string source) { return scan_tokens(source); }
+
+void print_tokens(std::list<Token> *list) {
+  for (std::list<Token>::iterator token = list->begin(); token != list->end();
+       ++token) {
+
+    if (token->literal != NULL) {
+      std::cout << token_name(token->type) << "(" << token->literal << "), ";
+    } else {
+      std::cout << token_name(token->type) << ", ";
+    }
+  }
+
+  std::cout << "\n";
+}

src/parser.c

@@ -1,21 +0,0 @@
-#include "parser.h"
-#include "tokens.h"
-
-enum ExprType {
-  Bin,
-};
-
-struct Binary {
-  Binary *left;
-  Token operator;
-  Binary *right;
-};
-
-union Expr {
-  Binary binary;
-};
-
-struct Expression {
-  enum ExprType type;
-  union Expr expr;
-};

src/parser.cpp

@@ -0,0 +1,111 @@
+// #include "tokens.hpp"
+// #include <stdbool.h>
+
+// static const TokenType eq[] = {BANG_EQUAL, EQUAL_EQUAL};
+// static const TokenType comp[] = {GREATER, GREATER_EQUAL, LESS, LESS_EQUAL};
+// static const TokenType unarytokens[] = {BANG, MINUS};
+
+// // static int current = -1;
+// // TokenList *tokens;
+
+// class Expression;
+
+// class Binary {
+// public:
+//   Expression *left;
+//   Token *operator;
+//   Expression *right;
+// };
+
+// typedef struct Grouping {
+//   Expression *expr;
+// } Grouping;
+
+// typedef struct Unary {
+//   Token *operator;
+//   Expression *expr;
+// } Unary;
+
+// class Expression {
+// public:
+//   enum ExprType { Bin, Grp, Lit, Una } type;
+//   union Expr {
+//     Binary *binary;
+//     Grouping *grouping;
+//     Token *literal;
+//     Unary *unary;
+//   } expr;
+// };
+
+// void parse(TokenList *tokenlist) {
+//   tokens = tokenlist;
+//   current = 0;
+// }
+
+// static Token *peek(void) { return tokenlist_get(tokens, current); }
+
+// static bool is_at_end(void) { return peek()->type == END_OF_FILE; }
+
+// static bool check(TokenType type) {
+//   if (is_at_end()) {
+//     return false;
+//   }
+//   return peek()->type == type;
+// }
+
+// static bool match(const TokenType tokens[], int n) {
+//   for (int i = 0; i < n; i++) {
+//     if (check(tokens[i])) {
+//     }
+//   }
+//   return false;
+// }
+
+// static Token previous(void) {
+//   Token t = {NUMBER, "", 0, 0};
+//   return t;
+// }
+
+// static Expression unary(void) {
+//   if (match(unarytokens, 2)) {
+//     Token operator= previous();
+//     Expression right = unary();
+//     Expression un;
+//     un.type = Una;
+//     Unary new_una = {&operator, & right };
+//     un.expr.unary = &new_una;
+//     return un;
+//   }
+//   return primary();
+// }
+
+// static Expression factor(void) {}
+
+// static Expression term(void) { Expression expr = factor(); }
+
+// static Expression comparison(void) {
+//   Expression expr = term();
+//   while (match(comp, 4)) {
+//     Token operator= previous();
+//     Expression right = term();
+
+//     Binary new_bin = {&expr, &operator, & right };
+//     expr.expr.binary = &new_bin;
+//     expr.type = Bin;
+//   }
+//   return expr;
+// }
+// static Expression equality(void) {
+//   Expression expr = comparison();
+
+//   while (match(eq, 2)) {
+//     Token operator= previous();
+//     Expression right = comparison();
+//     Binary new_bin = {&expr, &operator, & right };
+//     expr.expr.binary = &new_bin;
+//     expr.type = Bin;
+//   }
+//   return expr;
+// }
+
+// // static Expression expression(void) { return equality(); }

src/parser.h

@@ -1 +0,0 @@
-typedef struct Binary Binary;

src/scanner.cpp

@@ -1,14 +1,13 @@
-#include "scanner.h"
-#include "tokens.h"
-#include "utils.h"
-#include <stdbool.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
+#include "scanner.hpp"
+#include "tokens.hpp"
+#include <cstdbool>
+#include <iostream>
+#include <list>
+#include <string>
 
 static void scan_token(void);
-static void error(char *message);
-static void report(char *where, char *message);
+static void error(std::string message);
+static void report(std::string where, std::string message);
 static bool is_at_end(void);
 static bool match(char expected);
 static char peek(void);
@@ -18,25 +17,22 @@ static bool is_digit(char c);
 static void number(void);
 static bool is_alpha(char c);
 static bool is_alphanumeric(char c);
-static void identifier(void);
+static void identifier();
 
 static bool had_error = false;
-static int current_pos = -1;
+static size_t current_pos = -1;
 static int start = -1;
 static int current_line = -1;
-static char *source;
-static TokenList token_list;
+static std::string source;
+static std::list<Token> token_list;
 
-ScanResult scan_tokens(char *src) {
+ScanResult scan_tokens(std::string src) {
   current_pos = 0;
   start = 0;
   current_line = 1;
   source = src;
 
-  tokenlist_init(&token_list);
-  int len = (int)strlen(source);
-
-  while (current_pos < len) {
+  while (current_pos < source.length()) {
     start = current_pos;
     scan_token();
   }
@@ -53,25 +49,25 @@ ScanResult scan_tokens(char *src) {
 static void add_token(TokenType type) {
   Token token;
   token.type = type;
-  token.lexeme = substring(source, start, current_pos);
+  token.lexeme = source.substr(start, current_pos);
   token.literal = NULL;
   token.line = current_line;
 
-  tokenlist_add(&token_list, token);
+  token_list.push_front(token);
 }
 
-static void add_token_with_literal(TokenType type, char *literal) {
+static void add_token_with_literal(TokenType type, std::string literal) {
   Token token;
   token.type = type;
-  token.lexeme = substring(source, start, current_pos);
-  token.literal = literal;
+  token.lexeme = source.substr(start, current_pos);
+  token.literal = static_cast<void *>(&literal);
   token.line = current_line;
 
-  tokenlist_add(&token_list, token);
+  token_list.push_front(token);
 }
 
 static char advance(void) {
-  char c = source[current_pos++];
+  char c = source.at(current_pos++);
   return c;
 }
 
@@ -151,7 +147,7 @@ static void identifier(void) {
     advance();
   }
 
-  char *text = substring(source, start + 1, current_pos - start);
+  std::string text = source.substr(start + 1, current_pos - start);
 
   const TokenType *tokentype = get_keyword_token(text);
   if (tokentype == NULL) {
@@ -168,8 +164,7 @@ static void number(void) {
     advance();
   while (is_digit(peek()))
     advance();
-  add_token_with_literal(NUMBER,
-                         substring(source, start + 1, current_pos - start));
+  add_token_with_literal(NUMBER, source.substr(start + 1, current_pos - start));
 }
 
 bool is_digit(char c) { return c >= '0' && c <= '9'; }
@@ -188,7 +183,7 @@ void string(void) {
 
   advance();
 
-  char *string = substring(source, start + 2, current_pos - start - 2);
+  std::string string = source.substr(start + 2, current_pos - start - 2);
   add_token_with_literal(STRING, string);
 }
 
@@ -204,7 +199,7 @@ static bool match(char expected) {
 }
 
 static char peek_next(void) {
-  if (current_pos + 1 >= (int)strlen(source)) {
+  if (current_pos + 1 >= source.length()) {
     return '\0';
   }
   return source[current_pos + 1];
@@ -222,11 +217,12 @@ static bool is_alpha(char c) {
 
 static bool is_alphanumeric(char c) { return is_alpha(c) || is_digit(c); }
 
-static bool is_at_end(void) { return current_pos >= (int)strlen(source); }
+static bool is_at_end(void) { return current_pos >= source.length(); }
 
-static void error(char *message) { report("", message); }
+static void error(std::string message) { report("", message); }
 
-static void report(char *where, char *message) {
-  printf("*[Line %i] Error %s : %s\n", current_line, where, message);
+static void report(std::string where, std::string message) {
+  std::cout << "*[Line " << current_line << "] Error " << where << " : "
+            << message << "\n";
   had_error = true;
 }

src/scanner.hpp

@@ -1,19 +1,20 @@
 #ifndef SCANNER_H
 #define SCANNER_H
 
-#include "tokens.h"
-#include <stdbool.h>
-#include <string.h>
+#include "tokens.hpp"
+#include <cstdbool>
+#include <list>
+#include <string>
 
 typedef struct {
   bool had_error;
-  TokenList token_list;
+  std::list<Token> token_list;
 } ScanResult;
 
-ScanResult scan_tokens(char *source);
+ScanResult scan_tokens(std::string source);
 
 typedef struct {
-  const char *key;
+  const std::string key;
   const TokenType value;
 } Item;
 
@@ -23,14 +24,14 @@ static const Item keywords[] = {
     {"or", OR},     {"print", PRINT}, {"return", RETURN}, {"super", SUPER},
     {"this", THIS}, {"true", TRUE},   {"var", VAR},       {"while", WHILE}};
 
-inline static const TokenType *get_keyword_token(char *key) {
+inline static const TokenType *get_keyword_token(std::string key) {
   int low = 0;
   int high = sizeof(keywords) / sizeof(Item);
 
   while (low < high) {
     int mid = (low + high) / 2;
 
-    int c = strcmp(keywords[mid].key, key);
+    int c = keywords[mid].key.compare(key);
     if (c == 0) {
       return &keywords[mid].value;
     }

src/tokens.c

@@ -1,40 +0,0 @@
-#include "tokens.h"
-#include <stdio.h>
-#include <stdlib.h>
-
-void tokenlist_init(TokenList *list) {
-  list->tokens = malloc(sizeof(Token) * 32);
-  list->size = 0;
-  list->capacity = 32;
-}
-
-void tokenlist_add(TokenList *list, Token value) {
-  if (list->size >= list->capacity) {
-    list->capacity *= 2;
-    list->tokens = realloc(list->tokens, sizeof(Token) * list->capacity);
-  }
-  list->tokens[list->size] = value;
-  list->size += 1;
-}
-
-Token *tokenlist_get(TokenList *list, int index) {
-  if (index >= list->size || index < 0) {
-    printf("Index %d out of bounds for list of size %d\n", index, list->size);
-    exit(1);
-  }
-  return &list->tokens[index];
-}
-
-void tokenlist_print(TokenList *tokenlist) {
-  for (int i = 0; i < tokenlist->size; i++) {
-    Token *token = tokenlist_get(tokenlist, i);
-    if (token->literal != NULL) {
-      printf("%s(%s), ", token_name(token->type), (char *)token->literal);
-    } else {
-      printf("%s, ", token_name(token->type));
-    }
-  }
-  printf("\n");
-}
-
-void tokenlist_free(TokenList *list) { free(list->tokens); }

src/tokens.hpp

@@ -1,6 +1,8 @@
 #ifndef TOKENS_H
 #define TOKENS_H
 
+#include <string>
+
 typedef enum {
   LEFT_PAREN,
   RIGHT_PAREN,
@@ -59,25 +61,9 @@ static inline const char *token_name(TokenType type) {
 
 typedef struct {
   TokenType type;
-  char *lexeme;
+  std::string lexeme;
   void *literal;
   int line;
 } Token;
 
-typedef struct TokenList {
-  Token *tokens;
-  int size;
-  int capacity;
-} TokenList;
-
-void tokenlist_init(TokenList *list);
-
-void tokenlist_add(TokenList *list, Token value);
-
-Token *tokenlist_get(TokenList *list, int index);
-
-void tokenlist_print(TokenList *tokenlist);
-
-void tokenlist_free(TokenList *list);
-
 #endif

src/utils.c

@@ -1,19 +0,0 @@
-#include <stdlib.h>
-#include <stdio.h>
-
-char* substring(char* string, int position, int length){
-    char* ptr = malloc(length+1);
-    if (ptr == NULL) {
-        printf("out of memory");
-        exit(EXIT_FAILURE);
-    }
-
-    int c;
-    for (c=0; c < length; c+=1){
-        *(ptr+c) = *(string+position-1);
-        string += sizeof(char);
-    }
-    *(ptr+c) = '\0';
-
-    return ptr;
-}

src/utils.h

@@ -1,6 +0,0 @@
-#ifndef UTILS_H
-#define UTILS_H
-
-char* substring(char* string, int position, int length);
-
-#endif