// Copyright 2024 Gabriel Bjørnager Jensen.
//
// This file is part of bzipper.
//
// bzipper is free software: you can redistribute
// it and/or modify it under the terms of the GNU
// Lesser General Public License as published by
// the Free Software Foundation, either version 3
// of the License, or (at your option) any later
// version.
//
// bzipper is distributed in the hope that it will
// be useful, but WITHOUT ANY WARRANTY; without
// even the implied warranty of MERCHANTABILITY or
// FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Less-
// er General Public License along with bzipper. If
// not, see <https://www.gnu.org/licenses/>.
use core::error::Error as StdError;
use core::fmt::{Display, Formatter};
use core::str::Utf8Error;
/// Mapping of [`core::result::Result`].
pub type Result<T> = core::result::Result<T, Error>;
/// Denotes an error.
///
/// These variants are used when deserialisation fails.
/// Serialisations are assumed infallible.
#[derive(Debug)]
pub enum Error {
/// An array could not hold the requested amount of elements.
ArrayTooShort { req: usize, len: usize },
/// A string encountered an invalid UTF-8 sequence.
BadString { source: Utf8Error },
/// Bytes were requested on an empty stream.
EndOfStream { req: usize, rem: usize },
/// A boolean encountered a value outside (0) and (1).
InvalidBoolean { value: u8 },
/// An invalid code point was encountered.
///
/// This includes surrogate points in the inclusive range `U+D800` to `U+DFFF`, as well as values larger than `U+10FFFF`.
InvalidCodePoint { value: u32 },
/// An `isize` value couldn't fit into (16) bits.
IsizeOutOfRange { value: isize },
/// A non-zero integer encountered the value (0).
NullInteger,
/// A `usize` value couldn't fit into (16) bits.
UsizeOutOfRange { value: usize },
}
impl Display for Error {
fn fmt(&self, f: &mut Formatter) -> core::fmt::Result {
use Error::*;
match *self {
ArrayTooShort { req, len } => {
write!(f, "array of ({len}) element(s) cannot hold ({req})")
},
BadString { ref source } =>{
write!(f, "unable to parse utf8: \"{source}\"")
},
EndOfStream { req, rem } => {
write!(f, "({req}) byte(s) were requested but only ({rem}) byte(s) were left")
},
InvalidBoolean { value } => {
write!(f, "expected boolean but got {value:#02X}")
},
InvalidCodePoint { value } => {
write!(f, "code point U+{value:04X} is not valid")
},
IsizeOutOfRange { value } => {
write!(f, "signed size value ({value}) cannot be serialised: must be in the range ({}) to ({})", i16::MIN, i16::MAX)
},
NullInteger => {
write!(f, "expected non-zero integer but got (0)")
},
UsizeOutOfRange { value } => {
write!(f, "unsigned size value ({value}) cannot be serialised: must be at most ({})", u16::MAX)
},
}
}
}
impl StdError for Error {
fn source(&self) -> Option<&(dyn StdError + 'static)> {
use Error::*;
match *self {
BadString { ref source } => Some(source),
_ => None,
}
}
}
