Implementing a macro to define debug from display and adding Display trait implementation where needed

Display should not be implemented as Debug trait, but the existing macro promotes this figure of use.
The macro has been replaced with implement_debug_from_display and the Display trait has been implemented where needed.
The LowerHex trait has been implemented instead of Display for UintX types.

src/blockdata/opcodes.rs

@@ -14,7 +14,7 @@
 #[cfg(feature = "serde")] use crate::prelude::*;
 
 use core::{fmt, convert::From};
-use crate::internal_macros::display_from_debug;
+use crate::internal_macros::debug_from_display;
 
 // Note: I am deliberately not implementing PartialOrd or Ord on the
 //       opcode enum. If you want to check ranges of opcodes, etc.,
@@ -549,7 +549,7 @@ pub mod all {
     pub const OP_INVALIDOPCODE: All = All {code: 0xff};
 }
 
-impl fmt::Debug for All {
+impl fmt::Display for All {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         f.write_str("OP_")?;
         match *self {
@@ -745,7 +745,7 @@ impl From<u8> for All {
     }
 }
 
-display_from_debug!(All);
+debug_from_display!(All);
 
 #[cfg(feature = "serde")]
 #[cfg_attr(docsrs, doc(cfg(feature = "serde")))]
@@ -786,19 +786,6 @@ pub enum Class {
     Ordinary(Ordinary)
 }
 
-display_from_debug!(Class);
-
-#[cfg(feature = "serde")]
-#[cfg_attr(docsrs, doc(cfg(feature = "serde")))]
-impl serde::Serialize for Class {
-    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
-    where
-        S: serde::Serializer,
-    {
-        serializer.serialize_str(&self.to_string())
-    }
-}
-
 macro_rules! ordinary_opcode {
     ($($op:ident),*) => (
         #[repr(u8)]
@@ -808,6 +795,14 @@ macro_rules! ordinary_opcode {
             $( $op = all::$op.code ),*
         }
 
+        impl fmt::Display for Ordinary {
+            fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+                match *self {
+                   $(Ordinary::$op => { f.pad(stringify!($op)) }),*
+                }
+            }
+        }
+
         impl Ordinary {
             fn with(b: All) -> Self {
                 match b {
@@ -866,7 +861,6 @@ impl Ordinary {
     pub fn to_u8(self) -> u8 {
         self as u8
     }
-
 }
 
 #[cfg(test)]
@@ -1068,10 +1062,10 @@ mod tests {
         roundtrip!(unique, OP_NUMEQUAL);
         roundtrip!(unique, OP_NUMEQUALVERIFY);
         roundtrip!(unique, OP_NUMNOTEQUAL);
-        roundtrip!(unique, OP_LESSTHAN );
-        roundtrip!(unique, OP_GREATERTHAN );
-        roundtrip!(unique, OP_LESSTHANOREQUAL );
-        roundtrip!(unique, OP_GREATERTHANOREQUAL );
+        roundtrip!(unique, OP_LESSTHAN);
+        roundtrip!(unique, OP_GREATERTHAN);
+        roundtrip!(unique, OP_LESSTHANOREQUAL);
+        roundtrip!(unique, OP_GREATERTHANOREQUAL);
         roundtrip!(unique, OP_MIN);
         roundtrip!(unique, OP_MAX);
         roundtrip!(unique, OP_WITHIN);

src/blockdata/script.rs

@@ -18,7 +18,7 @@ use crate::io;
 use core::convert::TryFrom;
 use core::{fmt, default::Default};
 use core::ops::Index;
-use crate::internal_macros::display_from_debug;
+use crate::internal_macros::debug_from_display;
 
 #[cfg(feature = "serde")] use serde;
 
@@ -121,9 +121,16 @@ impl core::str::FromStr for Script {
 }
 
 /// An object which can be used to construct a script piece by piece.
-#[derive(PartialEq, Eq, Debug, Clone)]
+#[derive(PartialEq, Eq, Clone)]
 pub struct Builder(Vec<u8>, Option<opcodes::All>);
-display_from_debug!(Builder);
+
+impl fmt::Display for Builder {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        Script::bytes_to_asm_fmt(self.0.as_ref(), f)
+    }
+}
+
+debug_from_display!(Builder);
 
 impl<I> Index<I> for Builder
 where

src/internal_macros.rs

@@ -107,16 +107,16 @@ macro_rules! impl_array_newtype {
 }
 pub(crate) use impl_array_newtype;
 
-macro_rules! display_from_debug {
+macro_rules! debug_from_display {
     ($thing:ident) => {
-        impl core::fmt::Display for $thing {
+        impl core::fmt::Debug for $thing {
             fn fmt(&self, f: &mut core::fmt::Formatter) -> Result<(), core::fmt::Error> {
-                core::fmt::Debug::fmt(self, f)
+                core::fmt::Display::fmt(self, f)
             }
         }
     };
 }
-pub(crate) use display_from_debug;
+pub(crate) use debug_from_display;
 
 #[cfg(test)]
 macro_rules! hex_script (($s:expr) => (<$crate::Script as core::str::FromStr>::from_str($s).unwrap()));

src/util/uint.rs

@@ -127,7 +127,7 @@ macro_rules! construct_uint {
                 let your_bits = other.bits();
 
                 // Check for division by 0
-                assert!(your_bits != 0, "attempted to divide {} by zero", self);
+                assert!(your_bits != 0, "attempted to divide {:#x} by zero", self);
 
                 // Early return in case we are dividing by a larger number than us
                 if my_bits < your_bits {
@@ -393,10 +393,12 @@ macro_rules! construct_uint {
             }
         }
 
-        impl core::fmt::Debug for $name {
+        impl core::fmt::LowerHex for $name {
             fn fmt(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result {
                 let &$name(ref data) = self;
-                write!(f, "0x")?;
+                if f.alternate() {
+                    write!(f, "0x")?;
+                }
                 for ch in data.iter().rev() {
                     write!(f, "{:016x}", ch)?;
                 }
@@ -404,7 +406,11 @@ macro_rules! construct_uint {
             }
         }
 
-        $crate::internal_macros::display_from_debug!($name);
+        impl core::fmt::Debug for $name {
+            fn fmt(&self, f: &mut core::fmt::Formatter) -> core::fmt::Result {
+                write!(f,"{:#x}", self)
+            }
+        }
 
         impl $crate::consensus::Encodable for $name {
             #[inline]
@@ -565,17 +571,25 @@ mod tests {
 
     #[test]
     pub fn uint256_display_test() {
-        assert_eq!(format!("{}", Uint256::from_u64(0xDEADBEEF).unwrap()),
+        assert_eq!(format!("{:#x}", Uint256::from_u64(0xDEADBEEF).unwrap()),
                    "0x00000000000000000000000000000000000000000000000000000000deadbeef");
-        assert_eq!(format!("{}", Uint256::from_u64(u64::max_value()).unwrap()),
+        assert_eq!(format!("{:x}", Uint256::from_u64(0xDEADBEEF).unwrap()),
+                   "00000000000000000000000000000000000000000000000000000000deadbeef");
+        assert_eq!(format!("{:#x}", Uint256::from_u64(u64::max_value()).unwrap()),
                    "0x000000000000000000000000000000000000000000000000ffffffffffffffff");
 
         let max_val = Uint256([0xFFFFFFFFFFFFFFFF, 0xFFFFFFFFFFFFFFFF, 0xFFFFFFFFFFFFFFFF,
                                0xFFFFFFFFFFFFFFFF]);
-        assert_eq!(format!("{}", max_val),
+        assert_eq!(format!("{:#x}", max_val),
                    "0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff");
     }
 
+    #[test]
+    pub fn uint256_debug_test() {
+        assert_eq!(format!("{:?}", Uint256::from_u64(0xDEADBEEF).unwrap()),
+                   "0x00000000000000000000000000000000000000000000000000000000deadbeef");
+    }
+
     #[test]
     pub fn uint256_comp_test() {
         let small = Uint256([10u64, 0, 0, 0]);