/// List of all errors.
#[derive(Debug)]
pub enum Error {
/// An input data ended earlier than expected.
///
/// Should only appear on invalid input data.
/// Errors in a valid XML should be handled by errors below.
UnexpectedEndOfStream,
/// An input text contains unknown data.
UnexpectedData(usize),
/// A provided string doesn't have a valid data.
///
/// For example, if we try to parse a color form `zzz`
/// string - we will get this error.
/// But if we try to parse a number list like `1.2 zzz`,
/// then we will get `InvalidNumber`, because at least some data is valid.
InvalidValue,
/// An invalid/unexpected character.
///
/// The first byte is an actual one, others - expected.
///
/// We are using a single value to reduce the struct size.
InvalidChar(Vec<u8>, usize),
/// An unexpected character instead of an XML space.
///
/// The first string is an actual one, others - expected.
///
/// We are using a single value to reduce the struct size.
InvalidString(Vec<String>, usize),
/// An invalid number.
InvalidNumber(usize),
}
impl std::fmt::Display for Error {
fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
match *self {
Error::UnexpectedEndOfStream => {
write!(f, "unexpected end of stream")
}
Error::UnexpectedData(pos) => {
write!(f, "unexpected data at position {}", pos)
}
Error::InvalidValue => {
write!(f, "invalid value")
}
Error::InvalidChar(ref chars, pos) => {
// Vec<u8> -> Vec<String>
let list: Vec<String> = chars
.iter()
.skip(1)
.map(|c| String::from_utf8(vec![*c]).unwrap())
.collect();
write!(
f,
"expected '{}' not '{}' at position {}",
list.join("', '"),
chars[0] as char,
pos
)
}
Error::InvalidString(ref strings, pos) => {
write!(
f,
"expected '{}' not '{}' at position {}",
strings[1..].join("', '"),
strings[0],
pos
)
}
Error::InvalidNumber(pos) => {
write!(f, "invalid number at position {}", pos)
}
}
}
}
impl std::error::Error for Error {
fn description(&self) -> &str {
"an SVG data parsing error"
}
}