/rust/registry/src/index.crates.io-1949cf8c6b5b557f/regex-automata-0.1.10/src/error.rs

Source
use std::error;
use std::fmt;
use std::result;

use regex_syntax;

pub type Result<T> = result::Result<T, Error>;

/// An error that occurred during the construction of a DFA.
#[derive(Clone, Debug)]
pub struct Error {
    kind: ErrorKind,
}

/// The kind of error that occurred.
#[derive(Clone, Debug)]
pub enum ErrorKind {
    /// An error that occurred while parsing a regular expression. Note that
    /// this error may be printed over multiple lines, and is generally
    /// intended to be end user readable on its own.
    Syntax(String),
    /// An error that occurred because an unsupported regex feature was used.
    /// The message string describes which unsupported feature was used.
    ///
    /// The primary regex features that are unsupported are those that require
    /// look-around, such as the `^` and `$` anchors and the word boundary
    /// assertion `\b`. These may be supported in the future.
    Unsupported(String),
    /// An error that occurred when attempting to serialize a DFA to bytes.
    Serialize(String),
    /// An error that occurs when constructing a DFA would require the use of
    /// a state ID that overflows the chosen state ID representation. For
    /// example, if one is using `u8` for state IDs and builds a DFA with
    /// 257 states, then the last state's ID will be `256` which cannot be
    /// represented with `u8`.
    ///
    /// Typically, this error occurs in the determinization process of building
    /// a DFA (the conversion step from NFA to DFA). It can also occur when
    /// trying to build a smaller DFA from an existing one.
    StateIDOverflow {
        /// The maximum possible state ID.
        max: usize,
    },
    /// An error that occurs when premultiplication of state IDs is requested,
    /// but doing so would overflow the chosen state ID representation.
    ///
    /// When `max == requested_max`, then the state ID would overflow `usize`.
    PremultiplyOverflow {
        /// The maximum possible state id.
        max: usize,
        /// The maximum ID required by premultiplication.
        requested_max: usize,
    },
}

impl Error {
    /// Return the kind of this error.
    pub fn kind(&self) -> &ErrorKind {
        &self.kind
    }

    pub(crate) fn syntax(err: regex_syntax::Error) -> Error {
        Error { kind: ErrorKind::Syntax(err.to_string()) }
    }

    pub(crate) fn unsupported_anchor() -> Error {
        let msg = r"anchors such as ^, $, \A and \z are not supported";
        Error { kind: ErrorKind::Unsupported(msg.to_string()) }
    }

    pub(crate) fn unsupported_word() -> Error {
        let msg = r"word boundary assertions (\b and \B) are not supported";
        Error { kind: ErrorKind::Unsupported(msg.to_string()) }
    }

    pub(crate) fn unsupported_longest_match() -> Error {
        let msg = "unachored searches with longest match \
                   semantics are not supported";
        Error { kind: ErrorKind::Unsupported(msg.to_string()) }
    }

    pub(crate) fn serialize(message: &str) -> Error {
        Error { kind: ErrorKind::Serialize(message.to_string()) }
    }

    pub(crate) fn state_id_overflow(max: usize) -> Error {
        Error { kind: ErrorKind::StateIDOverflow { max } }
    }

    pub(crate) fn premultiply_overflow(
        max: usize,
        requested_max: usize,
    ) -> Error {
        Error { kind: ErrorKind::PremultiplyOverflow { max, requested_max } }
    }
}

impl error::Error for Error {
    fn description(&self) -> &str {
        match self.kind {
            ErrorKind::Syntax(_) => "syntax error",
            ErrorKind::Unsupported(_) => "unsupported syntax",
            ErrorKind::Serialize(_) => "serialization error",
            ErrorKind::StateIDOverflow { .. } => {
                "state id representation too small"
            }
            ErrorKind::PremultiplyOverflow { .. } => {
                "state id representation too small for premultiplication"
            }
        }
    }
}

impl fmt::Display for Error {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        match self.kind {
            ErrorKind::Syntax(ref msg) => write!(f, "{}", msg),
            ErrorKind::Unsupported(ref msg) => write!(f, "{}", msg),
            ErrorKind::Serialize(ref msg) => {
                write!(f, "DFA serialization error: {}", msg)
            }
            ErrorKind::StateIDOverflow { max } => write!(
                f,
                "building the DFA failed because it required building \
                 more states that can be identified, where the maximum \
                 ID for the chosen representation is {}",
                max,
            ),
            ErrorKind::PremultiplyOverflow { max, requested_max } => {
                if max == requested_max {
                    write!(
                        f,
                        "premultiplication of states requires the ability to \
                         represent a state ID greater than what can fit on \
                         this platform's usize, which is {}",
                        ::std::usize::MAX,
                    )
                } else {
                    write!(
                        f,
                        "premultiplication of states requires the ability to \
                         represent at least a state ID of {}, but the chosen \
                         representation only permits a maximum state ID of {}",
                        requested_max, max,
                    )
                }
            }
        }
    }
}

Line	Count	Source
1		use std::error;
2		use std::fmt;
3		use std::result;
4
5		use regex_syntax;
6
7		pub type Result<T> = result::Result<T, Error>;
8
9		/// An error that occurred during the construction of a DFA.
10		#[derive(Clone, Debug)]
11		pub struct Error {
12		kind: ErrorKind,
13		}
14
15		/// The kind of error that occurred.
16		#[derive(Clone, Debug)]
17		pub enum ErrorKind {
18		/// An error that occurred while parsing a regular expression. Note that
19		/// this error may be printed over multiple lines, and is generally
20		/// intended to be end user readable on its own.
21		Syntax(String),
22		/// An error that occurred because an unsupported regex feature was used.
23		/// The message string describes which unsupported feature was used.
24		///
25		/// The primary regex features that are unsupported are those that require
26		/// look-around, such as the `^` and `$` anchors and the word boundary
27		/// assertion `\b`. These may be supported in the future.
28		Unsupported(String),
29		/// An error that occurred when attempting to serialize a DFA to bytes.
30		Serialize(String),
31		/// An error that occurs when constructing a DFA would require the use of
32		/// a state ID that overflows the chosen state ID representation. For
33		/// example, if one is using `u8` for state IDs and builds a DFA with
34		/// 257 states, then the last state's ID will be `256` which cannot be
35		/// represented with `u8`.
36		///
37		/// Typically, this error occurs in the determinization process of building
38		/// a DFA (the conversion step from NFA to DFA). It can also occur when
39		/// trying to build a smaller DFA from an existing one.
40		StateIDOverflow {
41		/// The maximum possible state ID.
42		max: usize,
43		},
44		/// An error that occurs when premultiplication of state IDs is requested,
45		/// but doing so would overflow the chosen state ID representation.
46		///
47		/// When `max == requested_max`, then the state ID would overflow `usize`.
48		PremultiplyOverflow {
49		/// The maximum possible state id.
50		max: usize,
51		/// The maximum ID required by premultiplication.
52		requested_max: usize,
53		},
54		}
55
56		impl Error {
57		/// Return the kind of this error.
58	0	pub fn kind(&self) -> &ErrorKind {
59	0	&self.kind
60	0	}
61
62	0	pub(crate) fn syntax(err: regex_syntax::Error) -> Error {
63	0	Error { kind: ErrorKind::Syntax(err.to_string()) }
64	0	}
65
66	0	pub(crate) fn unsupported_anchor() -> Error {
67	0	let msg = r"anchors such as ^, $, \A and \z are not supported";
68	0	Error { kind: ErrorKind::Unsupported(msg.to_string()) }
69	0	}
70
71	0	pub(crate) fn unsupported_word() -> Error {
72	0	let msg = r"word boundary assertions (\b and \B) are not supported";
73	0	Error { kind: ErrorKind::Unsupported(msg.to_string()) }
74	0	}
75
76	0	pub(crate) fn unsupported_longest_match() -> Error {
77	0	let msg = "unachored searches with longest match \
78	0	semantics are not supported";
79	0	Error { kind: ErrorKind::Unsupported(msg.to_string()) }
80	0	}
81
82	0	pub(crate) fn serialize(message: &str) -> Error {
83	0	Error { kind: ErrorKind::Serialize(message.to_string()) }
84	0	}
85
86	0	pub(crate) fn state_id_overflow(max: usize) -> Error {
87	0	Error { kind: ErrorKind::StateIDOverflow { max } }
88	0	}
89
90	0	pub(crate) fn premultiply_overflow(
91	0	max: usize,
92	0	requested_max: usize,
93	0	) -> Error {
94	0	Error { kind: ErrorKind::PremultiplyOverflow { max, requested_max } }
95	0	}
96		}
97
98		impl error::Error for Error {
99	0	fn description(&self) -> &str {
100	0	match self.kind {
101	0	ErrorKind::Syntax(_) => "syntax error",
102	0	ErrorKind::Unsupported(_) => "unsupported syntax",
103	0	ErrorKind::Serialize(_) => "serialization error",
104		ErrorKind::StateIDOverflow { .. } => {
105	0	"state id representation too small"
106		}
107		ErrorKind::PremultiplyOverflow { .. } => {
108	0	"state id representation too small for premultiplication"
109		}
110		}
111	0	}
112		}
113
114		impl fmt::Display for Error {
115	0	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
116	0	match self.kind {
117	0	ErrorKind::Syntax(ref msg) => write!(f, "{}", msg),
118	0	ErrorKind::Unsupported(ref msg) => write!(f, "{}", msg),
119	0	ErrorKind::Serialize(ref msg) => {
120	0	write!(f, "DFA serialization error: {}", msg)
121		}
122	0	ErrorKind::StateIDOverflow { max } => write!(
123	0	f,
124	0	"building the DFA failed because it required building \
125	0	more states that can be identified, where the maximum \
126	0	ID for the chosen representation is {}",
127		max,
128		),
129	0	ErrorKind::PremultiplyOverflow { max, requested_max } => {
130	0	if max == requested_max {
131	0	write!(
132	0	f,
133	0	"premultiplication of states requires the ability to \
134	0	represent a state ID greater than what can fit on \
135	0	this platform's usize, which is {}",
136		::std::usize::MAX,
137		)
138		} else {
139	0	write!(
140	0	f,
141	0	"premultiplication of states requires the ability to \
142	0	represent at least a state ID of {}, but the chosen \
143	0	representation only permits a maximum state ID of {}",
144		requested_max, max,
145		)
146		}
147		}
148		}
149	0	}
150		}

Coverage Report

Created: 2025-12-28 06:31