use std::convert::From;
use std::fmt;
use std::num;
pub type Result<T> = std::result::Result<T, Error>;
#[derive(Debug, PartialEq)]
pub enum Error {
IllegalRequiredError(String),
IllegalDefaultError(String),
MissingRequiredArgument(String, String),
TooManyArguments(String, usize),
ParseBoolError(std::str::ParseBoolError),
ParseIntError(num::ParseIntError),
ParseFloatError(num::ParseFloatError),
UnknownCommand(String),
}
impl std::error::Error for Error {}
impl fmt::Display for Error {
fn fmt(&self, f: &mut fmt::Formatter) -> std::result::Result<(), fmt::Error> {
match self {
Error::IllegalDefaultError(parameter) => {
write!(f, "Error: Parameter '{}' cannot have a default", parameter)
}
Error::IllegalRequiredError(parameter) => {
write!(f, "Error: Parameter '{}' cannot be required", parameter)
}
Error::MissingRequiredArgument(command, parameter) => write!(
f,
"Error: Missing required argument '{}' for command '{}'",
parameter, command
),
Error::TooManyArguments(command, nargs) => write!(
f,
"Error: Command '{}' can have no more than {} arguments",
command, nargs,
),
Error::ParseBoolError(error) => write!(f, "Error: {}", error,),
Error::ParseFloatError(error) => write!(f, "Error: {}", error,),
Error::ParseIntError(error) => write!(f, "Error: {}", error,),
Error::UnknownCommand(command) => write!(f, "Error: Unknown command '{}'", command),
}
}
}
impl From<num::ParseIntError> for Error {
fn from(error: num::ParseIntError) -> Self {
Error::ParseIntError(error)
}
}
impl From<num::ParseFloatError> for Error {
fn from(error: num::ParseFloatError) -> Self {
Error::ParseFloatError(error)
}
}
impl From<std::str::ParseBoolError> for Error {
fn from(error: std::str::ParseBoolError) -> Self {
Error::ParseBoolError(error)
}
}