-const char *lex_entire_line (struct lexer *);
-const struct string *lex_entire_line_ds (struct lexer *);
-const char *lex_rest_of_line (struct lexer *, int *end_dot);
-void lex_preprocess_line (struct string *, enum getl_syntax,
+const char *lex_entire_line (const struct lexer *);
+const struct string *lex_entire_line_ds (const struct lexer *);
+const char *lex_rest_of_line (const struct lexer *);
+bool lex_end_dot (const struct lexer *);
+void lex_preprocess_line (struct string *, enum syntax_mode,