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#![macro_use]
use std::fmt;
use std::result;
#[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
pub struct Location {
pub line_number: usize,
}
#[derive(Debug)]
pub struct Error {
pub location: Location,
pub message: String,
}
impl fmt::Display for Error {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
if self.location.line_number == 0 {
write!(f, "command-line arguments: {}", self.message)
} else {
write!(f, "{}: {}", self.location.line_number, self.message)
}
}
}
pub type Result<T> = result::Result<T, Error>;
macro_rules! err {
( $loc:expr, $msg:expr ) => {
Err($crate::Error {
location: $loc.clone(),
message: String::from($msg),
})
};
( $loc:expr, $fmt:expr, $( $arg:expr ),+ ) => {
Err($crate::Error {
location: $loc.clone(),
message: format!( $fmt, $( $arg ),+ ),
})
};
}