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use crate::escape::Error as EscapeError;
use std::borrow::Cow;
use std::fmt;
use std::str::Utf8Error;
#[derive(Debug, PartialEq, Eq)]
pub enum ErrorReason {
Custom(Cow<'static, str>),
ExpectedLiteral(String),
InvalidEscape(char),
InvalidNumber,
InvalidUtf8,
UnescapeFailed(EscapeError),
UnexpectedControlCharacter(u8),
UnexpectedEos,
UnexpectedToken(char, &'static str),
}
use ErrorReason::*;
#[derive(Debug, PartialEq, Eq)]
pub struct Error {
reason: ErrorReason,
offset: Option<usize>,
}
impl Error {
pub fn new(reason: ErrorReason, offset: Option<usize>) -> Self {
Error { reason, offset }
}
pub fn custom(message: impl Into<Cow<'static, str>>) -> Error {
Error::new(ErrorReason::Custom(message.into()), None)
}
}
impl std::error::Error for Error {}
impl fmt::Display for Error {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
if let Some(offset) = self.offset {
write!(f, "Error at offset {}: ", offset)?;
}
match &self.reason {
Custom(msg) => write!(f, "failed to parse JSON: {}", msg),
ExpectedLiteral(literal) => write!(f, "expected literal: {}", literal),
InvalidEscape(escape) => write!(f, "invalid JSON escape: \\{}", escape),
InvalidNumber => write!(f, "invalid number"),
InvalidUtf8 => write!(f, "invalid UTF-8 codepoint in JSON stream"),
UnescapeFailed(err) => write!(f, "failed to unescape JSON string: {}", err),
UnexpectedControlCharacter(value) => write!(
f,
"encountered unescaped control character in string: 0x{:X}",
value
),
UnexpectedToken(token, expected) => write!(
f,
"unexpected token '{}'. Expected one of {}",
token, expected
),
UnexpectedEos => write!(f, "unexpected end of stream"),
}
}
}
impl From<Utf8Error> for ErrorReason {
fn from(_: Utf8Error) -> Self {
InvalidUtf8
}
}
impl From<EscapeError> for Error {
fn from(err: EscapeError) -> Self {
Error {
reason: ErrorReason::UnescapeFailed(err),
offset: None,
}
}
}