use crate::{Lens, LensOver, LensTrait, LensView}; #[derive(Clone, Copy)] pub struct _1Inner; pub const _1: Lens<_1Inner> = Lens(_1Inner); impl LensTrait for _1Inner {} macro_rules! make_tuples { ($f:ident, ( $( $v:ident ),* ), ( $( $t:ident ),* ) ) => { impl< $($t,)* > LensView<( $($t,)* )> for _1Inner { type Field = T; fn view(( $($v,)* ): ($($t,)*)) -> Self::Field { $f } } impl< $($t,)* > LensOver<( $($t,)* )> for _1Inner { fn over( mut tup: ($($t,)*), f: F ) -> ( $($t,)* ) where F: FnOnce(Self::Field) -> Self::Field { tup.1 = f(tup.1); tup } } impl<'a, $($t,)* > LensView<&'a ( $($t,)* )> for _1Inner { type Field = &'a T; fn view(( $($v,)* ): &'a ($($t,)*)) -> Self::Field { $f } } impl<'a, $($t,)* > LensView<&'a mut ( $($t,)* )> for _1Inner { type Field = &'a mut T; fn view(( $($v,)* ): &'a mut ($($t,)*)) -> Self::Field { $f } } }; } make_tuples!(t, (_u, t), (U, T)); make_tuples!(t, (_u, t, _v), (U, T, V)); make_tuples!(t, (_u, t, _v, _w), (U, T, V, W)); make_tuples!(t, (_u, t, _v, _w, _x), (U, T, V, W, X)); make_tuples!(t, (_u, t, _v, _w, _x, _y), (U, T, V, W, X, Y)); make_tuples!(t, (_u, t, _v, _w, _x, _y, _z), (U, T, V, W, X, Y, Z)); // not doing more cause i'm lazy, open a pr if you need more :) macro_rules! make_arrays { ($f:ident, $n:expr, [$( $v:ident ),*]) => { impl LensView<[T; $n]> for _1Inner { type Field = T; fn view([ $($v,)* ]: [T; $n]) -> Self::Field { $f } } impl LensOver<[T; $n]> for _1Inner { fn over( tup: [T; $n], fun: F ) -> [T; $n] where F: FnOnce(Self::Field) -> Self::Field { let [$($v,)*] = tup; let $f = fun( $f ); [$($v,)*] } } impl<'a, T> LensView<&'a [T; $n]> for _1Inner { type Field = &'a T; fn view([ $($v,)* ]: &'a [T; $n]) -> Self::Field { $f } } impl<'a, T> LensView<&'a mut [T; $n]> for _1Inner { type Field = &'a mut T; fn view([ $($v,)* ]: &'a mut [T; $n]) -> Self::Field { $f } } }; } make_arrays!(t, 2, [_a, t]); make_arrays!(t, 3, [_a, t, _b]); make_arrays!(t, 4, [_a, t, _b, _c]); make_arrays!(t, 5, [_a, t, _b, _c, _d]); make_arrays!(t, 6, [_a, t, _b, _c, _d, _e]); make_arrays!(t, 7, [_a, t, _b, _c, _d, _e, _g]);