fix some stuff

1 files changed, 25 insertions, 24 deletions

diff --git a/lexer.c b/lexer.c
index 9d0e596..f5072a1 100644
--- a/lexer.c
+++ b/lexer.c
@@ -10,6 +10,8 @@ static int lookahead;
 static const char* PATH;
 static unsigned long LINE, COL;
 
+static struct token tok = {.type = TK_NOT_FOUND};
+
 #define LEXER_PANIC(format, ...) {\
     fprintf(\
         stderr,\
@@ -21,6 +23,8 @@ static unsigned long LINE, COL;
     exit(1);\
 }
 
+static void lexer_advance();
+
 void lexer_load(const char* path) {
     if (file != NULL) {
         fclose(file);
@@ -32,6 +36,7 @@ void lexer_load(const char* path) {
     PATH = path;
     LINE = 1;
     COL = 1;
+    lexer_advance();
 }
 
 void lexer_close() {
@@ -41,20 +46,9 @@ void lexer_close() {
 }
 
 bool lexer_peek(struct token* p_token) {
-    if (file == NULL) return false;
-
-    long orig_offset = ftell(file);
-    int orig_lookahead = lookahead;
-    unsigned long orig_line = LINE, orig_col = COL;
-
-    bool rv = lexer_pop(p_token);
-
-    LINE = orig_line;
-    COL = orig_col;
-    lookahead = orig_lookahead;
-    fseek(file, orig_offset, SEEK_SET);
-
-    return rv;
+    if (tok.type == TK_NOT_FOUND) return false;
+    if (p_token != NULL) *p_token = tok;
+    return true;
 }
 
 #define is_whitespace(c) (c == ' ' || c == '\t' || c == '\n')
@@ -328,7 +322,7 @@ static enum token_type lex_simple_operator(char c) {
     LEXER_PANIC("unexpected token %c", c);
 }
 
-bool lexer_pop(struct token* p_token) {
+static bool lexer_read() {
     if (file == NULL) return false;
 
     // consume all whitespace and comments preceding the next token
@@ -355,21 +349,28 @@ bool lexer_pop(struct token* p_token) {
     }
     
     if (is_numeric(c))
-        lex_int_lit(p_token, c - '0');
+        lex_int_lit(&tok, c - '0');
     else if (c == '.' && is_numeric(lookahead))
-        lex_float_lit(p_token, 10, 0);
+        lex_float_lit(&tok, 10, 0);
     else if (is_ident_legal(c))
-        lex_ident(p_token, c);
+        lex_ident(&tok, c);
     else if (c == '\'')
-        lex_char_lit(p_token);
+        lex_char_lit(&tok);
     else if (c == '"')
-        lex_str_lit(p_token);
-    else if (!lex_complex_operator(p_token, c))
-        p_token->type = lex_simple_operator(c);
+        lex_str_lit(&tok);
+    else if (!lex_complex_operator(&tok, c))
+        tok.type = lex_simple_operator(c);
 
     return true;
 }
 
-bool lexer_eof() {
-    return lookahead == EOF;
+static void lexer_advance() {
+    if (!lexer_read()) tok.type = TK_NOT_FOUND;
+}
+
+bool lexer_pop(struct token* p_token) {
+    if (tok.type == TK_NOT_FOUND) return false;
+    if (p_token != NULL) *p_token = tok;
+    lexer_advance();
+    return true;
 }