field_mappings.rs

pub trait CodeValue: Sized {
	fn value(&self) -> &str;

	fn from_value(value: &str) -> Option<Self>;
}


macro_rules! code_value_enum {
    (
        $NAME:ident {
            $(
                $VARIANT:ident => $OUT:expr; {
                    $(
                        <= $IN:expr
                    ),*
                }
            ),*
        }
    ) => (
        #[derive(Clone, Copy, Debug)]
        pub enum $NAME {
            $(
                $VARIANT,
            )*
        }
        
        impl CodeValue for $NAME {
        	fn value(&self) -> &str {
        		match *self {
        		    $(
        		        $NAME::$VARIANT => $OUT,
        		    )*
        		}
        	}
        
        	fn from_value(value: &str) -> Option<$NAME> {
        		match value {
        		    $(
        		        $(
        		            $IN
        		        )|* => Some($NAME::$VARIANT),
        		    )*
        		    _ => None,
        		}
        	}
        }
    );
}

code_value_enum! {
    Foo {
        Variant1 => "Variant 1"; {
            <= "V1",
            <= "Variant 1"
        }
    }
}

fn main() {
    println!("{}", Foo::Variant1.value());
    println!("{:?}", Foo::from_value("V1"));
}