fst_regex/
error.rs

1use std::error;
2use std::fmt;
3
4use regex_syntax;
5
6/// An error that occurred while compiling a regular expression.
7#[derive(Debug)]
8pub enum Error {
9    /// A problem with the syntax of a regular expression.
10    Syntax(regex_syntax::Error),
11    /// Too many instructions resulting from the regular expression.
12    ///
13    /// The number given is the limit that was exceeded.
14    CompiledTooBig(usize),
15    /// Too many automata states resulting from the regular expression.
16    ///
17    /// This is distinct from `CompiledTooBig` because `TooManyStates` refers
18    /// to the DFA construction where as `CompiledTooBig` refers to the NFA
19    /// construction.
20    ///
21    /// The number given is the limit that was exceeded.
22    TooManyStates(usize),
23    /// Lazy quantifiers are not allowed (because they have no useful
24    /// interpretation when used purely for automata intersection, as is the
25    /// case in this crate).
26    NoLazy,
27    /// Word boundaries are currently not allowed.
28    ///
29    /// This restriction may be lifted in the future.
30    NoWordBoundary,
31    /// Empty or "zero width assertions" such as `^` or `$` are currently
32    /// not allowed.
33    ///
34    /// This restriction may be lifted in the future.
35    NoEmpty,
36    /// Byte literals such as `(?-u:\xff)` are not allowed.
37    ///
38    /// This restriction may be lifted in the future.
39    NoBytes,
40}
41
42impl From<regex_syntax::Error> for Error {
43    #[inline]
44    fn from(err: regex_syntax::Error) -> Error {
45        Error::Syntax(err)
46    }
47}
48
49impl fmt::Display for Error {
50    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
51        use self::Error::*;
52        match *self {
53            Syntax(ref err) => err.fmt(f),
54            CompiledTooBig(size_limit) => write!(
55                f,
56                "Compiled regex exceeds size limit of {} bytes",
57                size_limit
58            ),
59            TooManyStates(size_limit) => write!(
60                f,
61                "Compiled regex exceeds size limit of {} states",
62                size_limit
63            ),
64            NoLazy => write!(
65                f,
66                "Lazy reptition operators such as '+?' are \
67                                 not allowed."
68            ),
69            NoWordBoundary => write!(
70                f,
71                "Word boundary operators are not \
72                                           allowed."
73            ),
74            NoEmpty => write!(
75                f,
76                "Empty match operators are not allowed \
77                                  (hopefully temporary)."
78            ),
79            NoBytes => write!(f, "Byte literals are not allowed."),
80        }
81    }
82}
83
84impl error::Error for Error {
85    fn source(&self) -> Option<&(dyn error::Error + 'static)> {
86        use self::Error::*;
87        match *self {
88            Syntax(ref err) => Some(err),
89            _ => None,
90        }
91    }
92}
fst_regex/error.rs

fst_regex/
error.rs
