change lenses to take a ref

src/combinations.rs

@@ -1,6 +1,5 @@
 use crate::{
     lenses::{LensOver, LensView},
-    prisms::PrismPreview,
     Optics, OpticsTrait,
 };
 
@@ -27,8 +26,8 @@ where
 {
     type Field = B::Field;
 
-    fn view(thing: T) -> Self::Field {
+    fn view(&self, thing: T) -> Self::Field {
-        B::view(A::view(thing))
+        B::view(&self.1, A::view(&self.0, thing))
     }
 }
 
@@ -37,22 +36,10 @@ where
     A: LensOver<T>,
     B: LensOver<A::Field>,
 {
-    fn over<F>(thing: T, f: F) -> T
+    fn over<F>(&self, thing: T, f: F) -> T
     where
         F: FnOnce(Self::Field) -> Self::Field,
     {
-        A::over(thing, |b| B::over(b, f))
+        A::over(&self.0, thing, |b| B::over(&self.1, b, f))
-    }
-}
-
-impl<A, B, T> PrismPreview<T> for Combination<A, B>
-where
-    A: LensView<T>,
-    B: PrismPreview<A::Field>,
-{
-    type Field = B::Field;
-
-    fn preview(thing: T) -> Option<Self::Field> {
-        B::preview(A::view(thing))
     }
 }

src/fns.rs

@@ -10,7 +10,7 @@ where
     type Output = L::Field;
 
     extern "rust-call" fn call_once(self, args: (A,)) -> Self::Output {
-        L::view(args.0)
+        L::view(&self.0, args.0)
     }
 }
 impl<L, A> std::ops::FnMut<(A,)> for Optics<L>
@@ -18,7 +18,7 @@ where
     L: LensView<A>,
 {
     extern "rust-call" fn call_mut(&mut self, args: (A,)) -> Self::Output {
-        L::view(args.0)
+        L::view(&self.0, args.0)
     }
 }
 impl<L, A> std::ops::Fn<(A,)> for Optics<L>
@@ -26,7 +26,7 @@ where
     L: LensView<A>,
 {
     extern "rust-call" fn call(&self, args: (A,)) -> Self::Output {
-        L::view(args.0)
+        L::view(&self.0, args.0)
     }
 }
 
@@ -38,7 +38,7 @@ where
     type Output = A;
 
     extern "rust-call" fn call_once(self, args: (A, F)) -> Self::Output {
-        L::over(args.0, args.1)
+        L::over(&self.0, args.0, args.1)
     }
 }
 impl<L, A, F> std::ops::FnMut<(A, F)> for Optics<L>
@@ -47,7 +47,7 @@ where
     F: FnOnce(L::Field) -> L::Field,
 {
     extern "rust-call" fn call_mut(&mut self, args: (A, F)) -> Self::Output {
-        L::over(args.0, args.1)
+        L::over(&self.0, args.0, args.1)
     }
 }
 impl<L, A, F> std::ops::Fn<(A, F)> for Optics<L>
@@ -56,6 +56,6 @@ where
     F: FnOnce(L::Field) -> L::Field,
 {
     extern "rust-call" fn call(&self, args: (A, F)) -> Self::Output {
-        L::over(args.0, args.1)
+        L::over(&self.0, args.0, args.1)
     }
 }

src/lenses/first.rs

@@ -13,12 +13,13 @@ macro_rules! make_tuples {
       impl< $($t,)* > LensView<( $($t,)* )> for _0Inner {
             type Field = T;
 
-            fn view(( $($v,)* ): ($($t,)*)) -> Self::Field {
+            fn view(&self, ( $($v,)* ): ($($t,)*)) -> Self::Field {
                 $f
             }
         }
         impl< $($t,)* > LensOver<( $($t,)* )> for _0Inner {
             fn over<F>(
+                &self,
                 mut tup: ($($t,)*),
                 f: F
             ) -> ( $($t,)* )
@@ -33,14 +34,14 @@ macro_rules! make_tuples {
         impl<'a, $($t,)* > LensView<&'a ( $($t,)* )> for _0Inner {
             type Field = &'a T;
 
-            fn view(( $($v,)* ): &'a ($($t,)*)) -> Self::Field {
+            fn view(&self, ( $($v,)* ): &'a ($($t,)*)) -> Self::Field {
                 $f
             }
         }
         impl<'a, $($t,)* > LensView<&'a mut ( $($t,)* )> for _0Inner {
             type Field = &'a mut T;
 
-            fn view(( $($v,)* ): &'a mut ($($t,)*)) -> Self::Field {
+            fn view(&self, ( $($v,)* ): &'a mut ($($t,)*)) -> Self::Field {
                 $f
             }
         }
@@ -60,12 +61,13 @@ macro_rules! make_arrays {
       impl<T> LensView<[T; $n]> for _0Inner {
             type Field = T;
 
-            fn view([ $($v,)* ]: [T; $n]) -> Self::Field {
+            fn view(&self, [ $($v,)* ]: [T; $n]) -> Self::Field {
                 $f
             }
         }
       impl<T> LensOver<[T; $n]> for _0Inner {
             fn over<F>(
+              &self,
               tup: [T; $n],
               fun: F
             ) -> [T; $n]
@@ -81,14 +83,14 @@ macro_rules! make_arrays {
       impl<'a, T> LensView<&'a [T; $n]> for _0Inner {
             type Field = &'a T;
 
-            fn view([ $($v,)* ]: &'a [T; $n]) -> Self::Field {
+            fn view(&self, [ $($v,)* ]: &'a [T; $n]) -> Self::Field {
                 $f
             }
         }
       impl<'a, T> LensView<&'a mut [T; $n]> for _0Inner {
             type Field = &'a mut T;
 
-            fn view([ $($v,)* ]: &'a mut [T; $n]) -> Self::Field {
+            fn view(&self, [ $($v,)* ]: &'a mut [T; $n]) -> Self::Field {
                 $f
             }
         }

src/lenses/identity.rs

@@ -11,12 +11,12 @@ impl OpticsTrait for id {}
 impl<T> LensView<T> for id {
     type Field = T;
 
-    fn view(thing: T) -> Self::Field {
+    fn view(&self, thing: T) -> Self::Field {
         thing
     }
 }
 impl<T> LensOver<T> for id {
-    fn over<F>(thing: T, f: F) -> T
+    fn over<F>(&self, thing: T, f: F) -> T
     where
         F: FnOnce(Self::Field) -> Self::Field,
     {

src/lenses/mod.rs

@@ -6,23 +6,25 @@ pub use first::_0;
 mod second;
 pub use second::_1;
 
+mod to;
+
 use crate::{Optics, OpticsTrait};
 
 /// For lenses that allow viewing
 pub trait LensView<T>: OpticsTrait {
     type Field;
 
-    fn view(thing: T) -> Self::Field;
+    fn view(&self, thing: T) -> Self::Field;
 }
 
 /// For lenses that allow setting
 pub trait LensOver<T>: LensView<T> {
-    fn over<F>(thing: T, f: F) -> T
+    fn over<F>(&self, thing: T, f: F) -> T
     where
         F: FnOnce(Self::Field) -> Self::Field;
 
-    fn set(thing: T, v: Self::Field) -> T {
+    fn set(&self, thing: T, v: Self::Field) -> T {
-        Self::over(thing, |_| v)
+        Self::over(self, thing, |_| v)
     }
 }
 
@@ -32,30 +34,30 @@ where
 {
     type Field = L::Field;
 
-    fn view(thing: T) -> Self::Field {
+    fn view(&self, thing: T) -> Self::Field {
-        L::view(thing)
+        L::view(&self.0, thing)
     }
 }
 impl<L, T> LensOver<T> for Optics<L>
 where
     L: LensOver<T>,
 {
-    fn over<F>(thing: T, f: F) -> T
+    fn over<F>(&self, thing: T, f: F) -> T
     where
         F: FnOnce(Self::Field) -> Self::Field,
     {
-        L::over(thing, f)
+        L::over(&self.0, thing, f)
     }
 }
 
-pub fn view<T, L: LensView<T>>(_lens: L, thing: T) -> L::Field {
+pub fn view<T, L: LensView<T>>(lens: L, thing: T) -> L::Field {
-    L::view(thing)
+    L::view(&lens, thing)
 }
-pub fn set<T, L: LensOver<T>>(_lens: L, thing: T, v: L::Field) -> T {
+pub fn set<T, L: LensOver<T>>(lens: L, thing: T, v: L::Field) -> T {
-    L::set(thing, v)
+    L::set(&lens, thing, v)
 }
-pub fn over<T, L: LensOver<T>>(_lens: L, thing: T, f: impl FnOnce(L::Field) -> L::Field) -> T {
+pub fn over<T, L: LensOver<T>>(lens: L, thing: T, f: impl FnOnce(L::Field) -> L::Field) -> T {
-    L::over(thing, f)
+    L::over(&lens, thing, f)
 }
 
 #[cfg(test)]

src/lenses/second.rs

@@ -13,12 +13,13 @@ macro_rules! make_tuples {
       impl< $($t,)* > LensView<( $($t,)* )> for _1Inner {
             type Field = T;
 
-            fn view(( $($v,)* ): ($($t,)*)) -> Self::Field {
+            fn view(&self, ( $($v,)* ): ($($t,)*)) -> Self::Field {
                 $f
             }
         }
       impl< $($t,)* > LensOver<( $($t,)* )> for _1Inner {
             fn over<F>(
+                &self,
                 mut tup: ($($t,)*),
                 f: F
             ) -> ( $($t,)* )
@@ -33,14 +34,14 @@ macro_rules! make_tuples {
       impl<'a, $($t,)* > LensView<&'a ( $($t,)* )> for _1Inner {
             type Field = &'a T;
 
-            fn view(( $($v,)* ): &'a ($($t,)*)) -> Self::Field {
+            fn view(&self, ( $($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 {
+            fn view(&self, ( $($v,)* ): &'a mut ($($t,)*)) -> Self::Field {
                 $f
             }
         }
@@ -60,12 +61,13 @@ macro_rules! make_arrays {
       impl<T> LensView<[T; $n]> for _1Inner {
             type Field = T;
 
-            fn view([ $($v,)* ]: [T; $n]) -> Self::Field {
+            fn view(&self, [ $($v,)* ]: [T; $n]) -> Self::Field {
                 $f
             }
         }
       impl<T> LensOver<[T; $n]> for _1Inner {
             fn over<F>(
+              &self,
               tup: [T; $n],
               fun: F
             ) -> [T; $n]
@@ -81,14 +83,14 @@ macro_rules! make_arrays {
       impl<'a, T> LensView<&'a [T; $n]> for _1Inner {
             type Field = &'a T;
 
-            fn view([ $($v,)* ]: &'a [T; $n]) -> Self::Field {
+            fn view(&self, [ $($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 {
+            fn view(&self, [ $($v,)* ]: &'a mut [T; $n]) -> Self::Field {
                 $f
             }
         }

src/lib.rs

@@ -1,15 +1,5 @@
 #![feature(unboxed_closures, fn_traits)]
 
-// TODO add third_from_tuple, etc
-
-// TODO array traversals
-
-// TODO something for structs
-
-// TODO something for Ok, Some, etc
-
-// TODO make over work with changing types
-
 /// Base trait
 pub trait OpticsTrait {}