diff options
Diffstat (limited to 'py/lexer.c')
| -rw-r--r-- | py/lexer.c | 24 |
1 files changed, 18 insertions, 6 deletions
diff --git a/py/lexer.c b/py/lexer.c index e7d0e8144..b22cc2eae 100644 --- a/py/lexer.c +++ b/py/lexer.c @@ -361,13 +361,25 @@ STATIC void parse_string_literal(mp_lexer_t *lex, bool is_raw, bool is_fstring) vstr_add_byte(&lex->fstring_args, '('); // remember the start of this argument (if we need it for f'{a=}'). size_t i = lex->fstring_args.len; - // extract characters inside the { until we reach the - // format specifier or closing }. - // (MicroPython limitation) note: this is completely unaware of - // Python syntax and will not handle any expression containing '}' or ':'. - // e.g. f'{"}"}' or f'{foo({})}'. + // Extract characters inside the { until the bracket level + // is zero and we reach the conversion specifier '!', + // format specifier ':', or closing '}'. The conversion + // and format specifiers are left unchanged in the format + // string to be handled by str.format. + // (MicroPython limitation) note: this is completely + // unaware of Python syntax and will not handle any + // expression containing '}' or ':'. e.g. f'{"}"}' or f' + // {foo({})}'. However, detection of the '!' will + // specifically ensure that it's followed by [rs] and + // then either the format specifier or the closing + // brace. This allows the use of e.g. != in expressions. unsigned int nested_bracket_level = 0; - while (!is_end(lex) && (nested_bracket_level != 0 || !is_char_or(lex, ':', '}'))) { + while (!is_end(lex) && (nested_bracket_level != 0 + || !(is_char_or(lex, ':', '}') + || (is_char(lex, '!') + && is_char_following_or(lex, 'r', 's') + && is_char_following_following_or(lex, ':', '}')))) + ) { unichar c = CUR_CHAR(lex); if (c == '[' || c == '{') { nested_bracket_level += 1; |