use std::{convert::AsRef, str::FromStr};
use super::{Error, ArgRef};
use std::error::Error as StdError;
pub trait Argument : Sized {
fn parse(arg: impl AsRef<str>, arg: ArgRef) -> Result<Self, Error>;
}
impl<T: FromStr> Argument for T
where <T as FromStr>::Err : StdError + 'static
{
fn parse(val: impl AsRef<str>, arg: ArgRef) -> Result<Self, Error> {
let val = val.as_ref();
T::from_str(val).map_err(|e| Error::Parse(arg, Box::new(e)))
}
}
pub trait OptionalArg : Sized {
fn parse(arg: impl AsRef<str>, arg: ArgRef) -> Result<Self, Error>;
fn default() -> Self;
fn map_parse(val: Option<impl AsRef<str>>, arg: ArgRef) -> Result<Self, Error> {
match val {
Some(val) => Self::parse(val, arg),
None => Ok(Self::default())
}
}
}
impl<T: Argument> OptionalArg for Option<T> {
fn parse(val: impl AsRef<str>, arg: ArgRef) -> Result<Self, Error> {
Some(T::parse(val, arg)).transpose()
}
fn default() -> Self {
None
}
}
pub trait Flag : Default {
fn increment(&mut self);
}
impl Flag for bool {
fn increment(&mut self) {
*self = true;
}
}
impl Flag for Option<()> {
fn increment(&mut self) {
*self = Some(());
}
}
macro_rules! int_flag {
($int: ty) => {
impl $crate::Flag for $int {
fn increment(&mut self){
*self += 1;
}
}
}
}
int_flag!(usize);
int_flag!(u8);
int_flag!(u16);
int_flag!(u32);
int_flag!(u64);
int_flag!(isize);
int_flag!(i8);
int_flag!(i16);
int_flag!(i32);
int_flag!(i64);