add index to all iter helpers

src/draw.rs

@@ -49,6 +49,11 @@ pub use self::screen::*;
 pub trait Draw<T: Screen> {
     fn draw (self, to: &mut T) -> Usually<XYWH<T::Unit>>;
 }
+impl<T: Screen> Draw<T> for () {
+    fn draw (self, __: &mut T) -> Usually<XYWH<T::Unit>> {
+        Ok(Default::default())
+    }
+}
 impl<T: Screen, D: Draw<T>> Draw<T> for &D {
     fn draw (self, __: &mut T) -> Usually<XYWH<T::Unit>> {
         todo!()

src/space/iter.rs

@@ -11,23 +11,23 @@ use super::*;
 /// ].iter(), |x|x);
 /// ```
 pub fn iter <
-    S: Screen,
+    S: Screen,              // Target screen
-    D: Draw<S>,
+    D,                      // Input doesn't need to be [Draw]able, output does
-    V: Fn()->I,
+    V: Fn()->I,             // Function that returns the iterator
-    I: Iterator<Item = D>,
+    I: Iterator<Item = D>,  // Type of the iterator
-    F: Fn(&D)->dyn Draw<S>,
+    F: Fn(&D, usize)->dyn Draw<S>, // Function that returns [Draw]able from iterator item
 > (_items: V, _cb: F) -> impl Draw<S> {
     thunk(move|_to: &mut S|{ todo!() })
 }
 
 pub fn iter_north <'a, S: Screen, D: 'a, I: Iterator<Item = D>, U: Draw<S>> (
-    _iter: impl Fn()->I, _draw: impl Fn(D)->U,
+    _iter: impl Fn()->I, _draw: impl Fn(D, usize)->U,
 ) -> impl Draw<S> {
     thunk(move|_to: &mut S|{ todo!() })
 }
 
 pub fn iter_east <'a, S: Screen, D: 'a, I: Iterator<Item = D>, U: Draw<S>> (
-    _iter: impl Fn()->I, _draw: impl Fn(D)->U,
+    _iter: impl Fn()->I, _draw: impl Fn(D, usize)->U,
 ) -> impl Draw<S> {
     thunk(move|_to: &mut S|{ todo!() })
 }
@@ -39,8 +39,7 @@ pub fn iter_south <'a, S: Screen, D: 'a, I: Iterator<Item = D>, U: Draw<S>> (
 }
 
 pub fn iter_west <'a, S: Screen, D: 'a, I: Iterator<Item = D>, U: Draw<S>> (
-    _iter: impl Fn()->I, _draw: impl Fn(D)->U,
+    _iter: impl Fn()->I, _draw: impl Fn(D, usize)->U,
 ) -> impl Draw<S> {
     thunk(move|_to: &mut S|{ todo!() })
 }
-

src/term/border.rs

@@ -5,7 +5,7 @@ use super::*;
 /// ```
 /// /// TODO
 /// ```
-pub const fn border <T, S: BorderStyle> (on: bool, style: S, draw: impl Draw<Tui>) -> impl Draw<Tui> {
+pub const fn border (on: bool, style: impl BorderStyle, draw: impl Draw<Tui>) -> impl Draw<Tui> {
     let content = wh_pad(1, 1, draw);
     let outline = when(on, thunk(move|to: &mut Tui|{
         let XYWH(x, y, w, h) = to.1;