[tab:re.err]

Table 139: error_type values in the C locale [tab:re.err]

🔗	Value	Error condition
🔗	error_collate	The expression contains an invalid collating element name.
🔗	error_ctype	The expression contains an invalid character class name.
🔗	error_escape	The expression contains an invalid escaped character, or a trailing escape.
🔗	error_backref	The expression contains an invalid back reference.
🔗	error_brack	The expression contains mismatched `[` and `]`.
🔗	error_paren	The expression contains mismatched `(` and `)`.
🔗	error_brace	The expression contains mismatched `{` and `}`
🔗	error_badbrace	The expression contains an invalid range in a `{}` expression.
🔗	error_range	The expression contains an invalid character range, such as `[b-a]` in most encodings.
🔗	error_space	There is insufficient memory to convert the expression into a finite state machine.
🔗	error_badrepeat	One of `*?+{` is not preceded by a valid regular expression.
🔗	error_complexity	The complexity of an attempted match against a regular expression exceeds a pre-set level.
🔗	error_stack	There is insufficient memory to determine whether the regular expression matches the specified character sequence.

32 Regular expressions library [re]