Merge #220

220: [0.2.x] Fixes to digital compatibility shim r=ryankurte a=eldruin

I cherry-picked #138 and some improvements to docs and included #199.

Co-authored-by: Roma Sokolov <sokolov.r.v@gmail.com>
Co-authored-by: Ryan Kurte <ryankurte@gmail.com>
Co-authored-by: Diego Barrios Romero <eldruin@gmail.com>

CHANGELOG.md

@@ -12,6 +12,9 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ### Changed
 
+- Fix the input pin v2->v1 compatibility shim constructor, where `OldInputPin::new`
+  was incorrectly implemented for `v1::OutputPin` values.
+
 
 ## [v0.2.3] - 2019-05-09
 

src/digital/v1_compat.rs

@@ -1,7 +1,39 @@
-//! v1 compatibility wrapper
-//! this module adds reverse support for v2 digital traits
-//! v2 traits must be explicitly cast to the v1 version using `.into()`,
-//! and will panic on internal errors
+//! v1 compatibility wrappers
+//!
+//! This module provides wrappers to support use of v2 implementations with
+//! v1 consumers. v2 traits must be explicitly cast to the v1 version using
+//! `.into()`, and will panic on internal errors
+//!
+//! ```
+//! extern crate embedded_hal;
+//! use embedded_hal::digital::{v1, v2, v1_compat::OldOutputPin};
+//!
+//! struct NewOutputPinImpl {}
+//!
+//! impl v2::OutputPin for NewOutputPinImpl {
+//!     type Error = ();
+//!     fn set_low(&mut self) -> Result<(), Self::Error> { Ok(()) }
+//!     fn set_high(&mut self) -> Result<(), Self::Error>{ Ok(()) }
+//! }
+//!
+//! struct OldOutputPinConsumer<T: v1::OutputPin> {
+//!     _pin: T,
+//! }
+//!
+//! impl <T>OldOutputPinConsumer<T>
+//! where T: v1::OutputPin {
+//!     pub fn new(pin: T) -> OldOutputPinConsumer<T> {
+//!         OldOutputPinConsumer{ _pin: pin }
+//!     }
+//! }
+//!
+//! fn main() {
+//!     let pin = NewOutputPinImpl{};
+//!     let _consumer: OldOutputPinConsumer<OldOutputPin<_>> = OldOutputPinConsumer::new(pin.into());
+//! }
+//! ```
+//!
+
 
 #[allow(deprecated)]
 use super::v1;
@@ -60,7 +92,7 @@ where
 /// where errors will panic.
 #[cfg(feature = "unproven")]
 #[allow(deprecated)]
-impl <T, E> v1::StatefulOutputPin for OldOutputPin<T> 
+impl <T, E> v1::StatefulOutputPin for OldOutputPin<T>
 where
     T: v2::StatefulOutputPin<Error=E>,
     E: core::fmt::Debug,
@@ -84,7 +116,7 @@ pub struct OldInputPin<T> {
 #[cfg(feature = "unproven")]
 impl <T, E> OldInputPin<T>
 where
-    T: v2::OutputPin<Error=E>,
+    T: v2::InputPin<Error=E>,
     E: core::fmt::Debug,
 {
     /// Create an `OldInputPin` wrapper around a `v2::InputPin`.
@@ -159,8 +191,8 @@ mod tests {
     }
 
     #[allow(deprecated)]
-    impl <T>OldOutputPinConsumer<T> 
-    where T: v1::OutputPin 
+    impl <T>OldOutputPinConsumer<T>
+    where T: v1::OutputPin
     {
         pub fn new(pin: T) -> OldOutputPinConsumer<T> {
             OldOutputPinConsumer{ _pin: pin }
@@ -181,7 +213,7 @@ mod tests {
         assert_eq!(o.inner().state, true);
 
         o.set_low();
-        assert_eq!(o.inner().state, false);   
+        assert_eq!(o.inner().state, false);
     }
 
     #[test]
@@ -220,8 +252,8 @@ mod tests {
 
     #[cfg(feature = "unproven")]
     #[allow(deprecated)]
-    impl <T>OldInputPinConsumer<T> 
-    where T: v1::InputPin 
+    impl <T>OldInputPinConsumer<T>
+    where T: v1::InputPin
     {
         pub fn new(pin: T) -> OldInputPinConsumer<T> {
             OldInputPinConsumer{ _pin: pin }

src/digital/v2_compat.rs

@@ -1,5 +1,36 @@
 //! v2 compatibility shims
-//! this module adds implicit forward support to v1 digital traits
+//! 
+//! This module adds implicit forward support to v1 digital traits,
+//! allowing v1 implementations to be directly used with v2 consumers.
+//! 
+//! ```
+//! extern crate embedded_hal;
+//! use embedded_hal::digital::{v1, v2};
+//! 
+//! struct OldOutputPinImpl { }
+//! 
+//! impl v1::OutputPin for OldOutputPinImpl {
+//!     fn set_low(&mut self) { }
+//!     fn set_high(&mut self) { }
+//! }
+//! 
+//! struct NewOutputPinConsumer<T: v2::OutputPin> {
+//!     _pin: T,
+//! }
+//! 
+//! impl <T>NewOutputPinConsumer<T> 
+//! where T: v2::OutputPin {
+//!     pub fn new(pin: T) -> NewOutputPinConsumer<T> {
+//!         NewOutputPinConsumer{ _pin: pin }
+//!     }
+//! }
+//! 
+//! fn main() {
+//!     let pin = OldOutputPinImpl{};
+//!     let _consumer = NewOutputPinConsumer::new(pin);
+//! }
+//! ```
+//! 
 
 #[allow(deprecated)]
 use super::v1;
@@ -39,6 +70,9 @@ where
      }
 }
 
+#[cfg(feature = "unproven")]
+#[allow(deprecated)]
+impl<T> v2::toggleable::Default for T where T: v1::toggleable::Default {}
 
 /// Implementation of fallible `v2::InputPin` for `v1::InputPin` digital traits
 #[cfg(feature = "unproven")]
@@ -81,6 +115,20 @@ mod tests {
         }
     }
 
+    #[allow(deprecated)]
+    impl v1::StatefulOutputPin for OldOutputPinImpl {
+        fn is_set_low(&self) -> bool {
+            self.state == false
+        }
+
+        fn is_set_high(&self) -> bool {
+            self.state == true
+        }
+    }
+
+    #[allow(deprecated)]
+    impl v1::toggleable::Default for OldOutputPinImpl {}
+
     struct NewOutputPinConsumer<T: v2::OutputPin> {
         _pin: T,
     }
@@ -92,6 +140,25 @@ mod tests {
         }
     }
 
+    struct NewToggleablePinConsumer<T: v2::ToggleableOutputPin> {
+        _pin: T,
+    }
+
+    impl<T> NewToggleablePinConsumer<T>
+    where
+        T: v2::ToggleableOutputPin,
+    {
+        pub fn new(pin: T) -> NewToggleablePinConsumer<T> {
+            NewToggleablePinConsumer { _pin: pin }
+        }
+    }
+
+    #[test]
+    fn v2_v1_toggleable_implicit() {
+        let i = OldOutputPinImpl { state: false };
+        let _c = NewToggleablePinConsumer::new(i);
+    }
+
     #[test]
     fn v2_v1_output_implicit() {
         let i = OldOutputPinImpl{state: false};