Added string and character lexing

include/sync/lexer.h

@@ -16,6 +16,8 @@ typedef enum {
     TOKEN_RBRACE,
     TOKEN_LBRACKET,
     TOKEN_RBRACKET,
+    TOKEN_CHARACTER,
+    TOKEN_STRING,
 } TokenType;
 
 typedef struct {

src/lexer.c

@@ -25,18 +25,18 @@ static char peek(Lexer *lexer) {
     return lexer->source[lexer->pos];
 }
 
-static char double_peek(Lexer *lexer) {
-    return lexer->source[lexer->pos+1];
+static char far_peek(Lexer *lexer, size_t index) {
+    return lexer->source[lexer->pos + index];
 }
 
-static char advance(Lexer *lexer) {
+static void advance(Lexer *lexer) {
     if (lexer->source[lexer->pos] == '\n') {
         lexer->line++;
         lexer->column = 1;
     } else {
         lexer->column++;
     }
-    return lexer->source[lexer->pos++];
+    lexer->source[lexer->pos++];
 }
 
 typedef enum {
@@ -56,6 +56,20 @@ static char is_digit_char(char c, DigitFlags flags) {
     return isdigit(c) || c == '_';
 }
 
+static char is_digit_after(char c) {
+    return
+        isspace(c) ||
+        c == '\0' ||
+        c == ',' ||
+        c == ')' ||
+        c == '(' ||
+        c == '}' ||
+        c == '{' ||
+        c == ']' ||
+        c == '[' ||
+        c == ';';
+}
+
 static char is_identifier_start(char c) {
     return isalpha(c) || c == '_';
 }
@@ -77,7 +91,7 @@ TokenResult lexer_next(Lexer *lexer) {
 
     while (isspace(peek(lexer)) || peek(lexer) == '/') {
         // Skip Comments
-        if (peek(lexer) == '/' && double_peek(lexer) == '/')
+        if (peek(lexer) == '/' && far_peek(lexer, 1) == '/')
             while (peek(lexer) != '\n') advance(lexer);
         // Skip whitespace
         while (isspace(peek(lexer))) advance(lexer);
@@ -108,13 +122,39 @@ TokenResult lexer_next(Lexer *lexer) {
             }
         }
         while (is_digit_char(peek(lexer), flags)) advance(lexer);
-        if (isspace(peek(lexer)) || peek(lexer) == ';' || peek(lexer) == '\0' || peek(lexer) == ')' || peek(lexer) == '(' || peek(lexer) == ',') {
+        if (is_digit_after(peek(lexer))) {
             return lexer_result(lexer, TOKEN_NUMBER, start, start_line);
         } else {
             return lexer_error(lexer, "Invalid number format", start, start_line);
         }
     }
 
+    // Characters
+    if (c == '\'') {
+        advance(lexer); // Opening `'`
+        if (peek(lexer) == '\\') advance(lexer); // Slash
+        advance(lexer); // Char
+        if (peek(lexer) == '\'') {
+            advance(lexer); // Closing `'`
+            return lexer_result(lexer, TOKEN_CHARACTER, start, start_line);
+        } else return lexer_error(lexer, "Invalid character format", start, start_line);
+    }
+
+    // Strings
+    if (c == '"') {
+        advance(lexer);
+        while (peek(lexer) != '"') {
+            if (peek(lexer) == '\\') {
+                advance(lexer);
+            } else if (peek(lexer) == '\n') {
+                return lexer_error(lexer, "Invalid string format", start, start_line);
+            }
+            advance(lexer);
+        }
+        advance(lexer);
+        return lexer_result(lexer, TOKEN_STRING, start, start_line);
+    }
+
     // Identifiers
     if (is_identifier_start(c)) {
         while (is_identifier_char(peek(lexer))) advance(lexer);

src/main.c

@@ -4,11 +4,12 @@
 #include "sync/lexer.h"
 
 static void print_token(Token token) {
-    printf("Token: %-15s | Text: '%.*s'\n",
+    printf("Token: %-15s | Text: %.*s\n",
         (const char *[]){
             "EOF", "IDENTIFIER", "NUMBER", "OPERATOR",
             "LPAREN", "RPAREN", "SEMICOLON", "LBRACE",
-            "RBRACE", "LBRACKET", "RBRACKET"
+            "RBRACE", "LBRACKET", "RBRACKET", "CHARACTER",
+            "STRING"
         }[token.type],
         (int)token.length, token.start
     );
@@ -46,6 +47,9 @@ int main(void) {
             fprintf(stderr, "Error: %s\n", result.error.message);
             fprintf(stderr, "\tFilename: %s\n", result.error.file_info.filename);
             fprintf(stderr, "\tLine: %zi\n", result.error.file_info.line);
+            fprintf(stderr, "\tColumn: %zi\n", result.error.file_info.column);
+            free(source);
+            return 1;
         }
     } while (result.type != SYNC_ERROR && result.result.type != TOKEN_EOF);