From 827970ebe9fcce27ada9f71977895666f56032be Mon Sep 17 00:00:00 2001 From: Trevor Gross Date: Thu, 18 Jul 2024 20:33:22 -0400 Subject: [PATCH] Implement `debug_more_non_exhaustive` Add a `.finish_non_exhaustive()` method to `DebugTuple`, `DebugSet`, `DebugList`, and `DebugMap`. This indicates that the structures have remaining items with `..`. This implements the ACP at . --- library/core/src/fmt/builders.rs | 200 ++++++++++++++++++ library/core/tests/fmt/builders.rs | 322 ++++++++++++++++++++++++++++- library/core/tests/lib.rs | 1 + 3 files changed, 521 insertions(+), 2 deletions(-) diff --git a/library/core/src/fmt/builders.rs b/library/core/src/fmt/builders.rs index 944f7c0850706..1d04320831df3 100644 --- a/library/core/src/fmt/builders.rs +++ b/library/core/src/fmt/builders.rs @@ -360,6 +360,51 @@ impl<'a, 'b: 'a> DebugTuple<'a, 'b> { self } + /// Marks the tuple struct as non-exhaustive, indicating to the reader that there are some + /// other fields that are not shown in the debug representation. + /// + /// # Examples + /// + /// ``` + /// #![feature(debug_more_non_exhaustive)] + /// + /// use std::fmt; + /// + /// struct Foo(i32, String); + /// + /// impl fmt::Debug for Foo { + /// fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result { + /// fmt.debug_tuple("Foo") + /// .field(&self.0) + /// .finish_non_exhaustive() // Show that some other field(s) exist. + /// } + /// } + /// + /// assert_eq!( + /// format!("{:?}", Foo(10, "secret!".to_owned())), + /// "Foo(10, ..)", + /// ); + /// ``` + #[unstable(feature = "debug_more_non_exhaustive", issue = "127942")] + pub fn finish_non_exhaustive(&mut self) -> fmt::Result { + self.result = self.result.and_then(|_| { + if self.fields > 0 { + if self.is_pretty() { + let mut slot = None; + let mut state = Default::default(); + let mut writer = PadAdapter::wrap(self.fmt, &mut slot, &mut state); + writer.write_str("..\n")?; + self.fmt.write_str(")") + } else { + self.fmt.write_str(", ..)") + } + } else { + self.fmt.write_str("(..)") + } + }); + self.result + } + /// Finishes output and returns any error encountered. /// /// # Examples @@ -554,6 +599,56 @@ impl<'a, 'b: 'a> DebugSet<'a, 'b> { self } + /// Marks the set as non-exhaustive, indicating to the reader that there are some other + /// elements that are not shown in the debug representation. + /// + /// # Examples + /// + /// ``` + /// #![feature(debug_more_non_exhaustive)] + /// + /// use std::fmt; + /// + /// struct Foo(Vec); + /// + /// impl fmt::Debug for Foo { + /// fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result { + /// // Print at most two elements, abbreviate the rest + /// let mut f = fmt.debug_set(); + /// let mut f = f.entries(self.0.iter().take(2)); + /// if self.0.len() > 2 { + /// f.finish_non_exhaustive() + /// } else { + /// f.finish() + /// } + /// } + /// } + /// + /// assert_eq!( + /// format!("{:?}", Foo(vec![1, 2, 3, 4])), + /// "{1, 2, ..}", + /// ); + /// ``` + #[unstable(feature = "debug_more_non_exhaustive", issue = "127942")] + pub fn finish_non_exhaustive(&mut self) -> fmt::Result { + self.inner.result = self.inner.result.and_then(|_| { + if self.inner.has_fields { + if self.inner.is_pretty() { + let mut slot = None; + let mut state = Default::default(); + let mut writer = PadAdapter::wrap(self.inner.fmt, &mut slot, &mut state); + writer.write_str("..\n")?; + self.inner.fmt.write_str("}") + } else { + self.inner.fmt.write_str(", ..}") + } + } else { + self.inner.fmt.write_str("..}") + } + }); + self.inner.result + } + /// Finishes output and returns any error encountered. /// /// # Examples @@ -697,6 +792,55 @@ impl<'a, 'b: 'a> DebugList<'a, 'b> { self } + /// Marks the list as non-exhaustive, indicating to the reader that there are some other + /// elements that are not shown in the debug representation. + /// + /// # Examples + /// + /// ``` + /// #![feature(debug_more_non_exhaustive)] + /// + /// use std::fmt; + /// + /// struct Foo(Vec); + /// + /// impl fmt::Debug for Foo { + /// fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result { + /// // Print at most two elements, abbreviate the rest + /// let mut f = fmt.debug_list(); + /// let mut f = f.entries(self.0.iter().take(2)); + /// if self.0.len() > 2 { + /// f.finish_non_exhaustive() + /// } else { + /// f.finish() + /// } + /// } + /// } + /// + /// assert_eq!( + /// format!("{:?}", Foo(vec![1, 2, 3, 4])), + /// "[1, 2, ..]", + /// ); + /// ``` + #[unstable(feature = "debug_more_non_exhaustive", issue = "127942")] + pub fn finish_non_exhaustive(&mut self) -> fmt::Result { + self.inner.result.and_then(|_| { + if self.inner.has_fields { + if self.inner.is_pretty() { + let mut slot = None; + let mut state = Default::default(); + let mut writer = PadAdapter::wrap(self.inner.fmt, &mut slot, &mut state); + writer.write_str("..\n")?; + self.inner.fmt.write_str("]") + } else { + self.inner.fmt.write_str(", ..]") + } + } else { + self.inner.fmt.write_str("..]") + } + }) + } + /// Finishes output and returns any error encountered. /// /// # Examples @@ -973,6 +1117,62 @@ impl<'a, 'b: 'a> DebugMap<'a, 'b> { self } + /// Marks the map as non-exhaustive, indicating to the reader that there are some other + /// entries that are not shown in the debug representation. + /// + /// # Examples + /// + /// ``` + /// #![feature(debug_more_non_exhaustive)] + /// + /// use std::fmt; + /// + /// struct Foo(Vec<(String, i32)>); + /// + /// impl fmt::Debug for Foo { + /// fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result { + /// // Print at most two elements, abbreviate the rest + /// let mut f = fmt.debug_map(); + /// let mut f = f.entries(self.0.iter().take(2).map(|&(ref k, ref v)| (k, v))); + /// if self.0.len() > 2 { + /// f.finish_non_exhaustive() + /// } else { + /// f.finish() + /// } + /// } + /// } + /// + /// assert_eq!( + /// format!("{:?}", Foo(vec![ + /// ("A".to_string(), 10), + /// ("B".to_string(), 11), + /// ("C".to_string(), 12), + /// ])), + /// r#"{"A": 10, "B": 11, ..}"#, + /// ); + /// ``` + #[unstable(feature = "debug_more_non_exhaustive", issue = "127942")] + pub fn finish_non_exhaustive(&mut self) -> fmt::Result { + self.result = self.result.and_then(|_| { + assert!(!self.has_key, "attempted to finish a map with a partial entry"); + + if self.has_fields { + if self.is_pretty() { + let mut slot = None; + let mut state = Default::default(); + let mut writer = PadAdapter::wrap(self.fmt, &mut slot, &mut state); + writer.write_str("..\n")?; + self.fmt.write_str("}") + } else { + self.fmt.write_str(", ..}") + } + } else { + self.fmt.write_str("..}") + } + }); + self.result + } + /// Finishes output and returns any error encountered. /// /// # Panics diff --git a/library/core/tests/fmt/builders.rs b/library/core/tests/fmt/builders.rs index 7b73f13815107..ba4801f5912b8 100644 --- a/library/core/tests/fmt/builders.rs +++ b/library/core/tests/fmt/builders.rs @@ -257,6 +257,80 @@ mod debug_tuple { 10/20, ), "world", +)"#, + format!("{Bar:#?}") + ); + } + + #[test] + fn test_empty_non_exhaustive() { + struct Foo; + + impl fmt::Debug for Foo { + fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result { + fmt.debug_tuple("Foo").finish_non_exhaustive() + } + } + + assert_eq!("Foo(..)", format!("{Foo:?}")); + assert_eq!("Foo(..)", format!("{Foo:#?}")); + } + + #[test] + fn test_multiple_and_non_exhaustive() { + struct Foo; + + impl fmt::Debug for Foo { + fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result { + fmt.debug_tuple("Foo") + .field(&true) + .field(&format_args!("{}/{}", 10, 20)) + .finish_non_exhaustive() + } + } + + assert_eq!("Foo(true, 10/20, ..)", format!("{Foo:?}")); + assert_eq!( + "Foo( + true, + 10/20, + .. +)", + format!("{Foo:#?}") + ); + } + + #[test] + fn test_nested_non_exhaustive() { + struct Foo; + + impl fmt::Debug for Foo { + fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result { + fmt.debug_tuple("Foo") + .field(&true) + .field(&format_args!("{}/{}", 10, 20)) + .finish_non_exhaustive() + } + } + + struct Bar; + + impl fmt::Debug for Bar { + fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result { + fmt.debug_tuple("Bar").field(&Foo).field(&"world").finish_non_exhaustive() + } + } + + assert_eq!(r#"Bar(Foo(true, 10/20, ..), "world", ..)"#, format!("{Bar:?}")); + assert_eq!( + r#"Bar( + Foo( + true, + 10/20, + .. + ), + "world", + .. )"#, format!("{Bar:#?}") ); @@ -371,8 +445,7 @@ mod debug_map { } assert_eq!( - r#"{"foo": {"bar": true, 10: 10/20}, \ - {"bar": true, 10: 10/20}: "world"}"#, + r#"{"foo": {"bar": true, 10: 10/20}, {"bar": true, 10: 10/20}: "world"}"#, format!("{Bar:?}") ); assert_eq!( @@ -471,6 +544,103 @@ mod debug_map { let _ = format!("{Foo:?}"); } + + #[test] + fn test_empty_non_exhaustive() { + struct Foo; + + impl fmt::Debug for Foo { + fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result { + fmt.debug_map().finish_non_exhaustive() + } + } + + assert_eq!("{..}", format!("{Foo:?}")); + assert_eq!("{..}", format!("{Foo:#?}")); + } + + #[test] + fn test_multiple_and_non_exhaustive() { + struct Entry; + + impl fmt::Debug for Entry { + fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result { + fmt.debug_map() + .entry(&"bar", &true) + .entry(&10, &format_args!("{}/{}", 10, 20)) + .finish_non_exhaustive() + } + } + + struct KeyValue; + + impl fmt::Debug for KeyValue { + fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result { + fmt.debug_map() + .key(&"bar") + .value(&true) + .key(&10) + .value(&format_args!("{}/{}", 10, 20)) + .finish_non_exhaustive() + } + } + + assert_eq!(format!("{Entry:?}"), format!("{KeyValue:?}")); + assert_eq!(format!("{Entry:#?}"), format!("{KeyValue:#?}")); + + assert_eq!(r#"{"bar": true, 10: 10/20, ..}"#, format!("{Entry:?}")); + assert_eq!( + r#"{ + "bar": true, + 10: 10/20, + .. +}"#, + format!("{Entry:#?}") + ); + } + + #[test] + fn test_nested_non_exhaustive() { + struct Foo; + + impl fmt::Debug for Foo { + fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result { + fmt.debug_map() + .entry(&"bar", &true) + .entry(&10, &format_args!("{}/{}", 10, 20)) + .finish_non_exhaustive() + } + } + + struct Bar; + + impl fmt::Debug for Bar { + fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result { + fmt.debug_map().entry(&"foo", &Foo).entry(&Foo, &"world").finish_non_exhaustive() + } + } + + assert_eq!( + r#"{"foo": {"bar": true, 10: 10/20, ..}, {"bar": true, 10: 10/20, ..}: "world", ..}"#, + format!("{Bar:?}") + ); + assert_eq!( + r#"{ + "foo": { + "bar": true, + 10: 10/20, + .. + }, + { + "bar": true, + 10: 10/20, + .. + }: "world", + .. +}"#, + format!("{Bar:#?}") + ); + } } mod debug_set { @@ -555,6 +725,80 @@ mod debug_set { 10/20, }, "world", +}"#, + format!("{Bar:#?}") + ); + } + + #[test] + fn test_empty_non_exhaustive() { + struct Foo; + + impl fmt::Debug for Foo { + fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result { + fmt.debug_set().finish_non_exhaustive() + } + } + + assert_eq!("{..}", format!("{Foo:?}")); + assert_eq!("{..}", format!("{Foo:#?}")); + } + + #[test] + fn test_multiple_and_non_exhaustive() { + struct Foo; + + impl fmt::Debug for Foo { + fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result { + fmt.debug_set() + .entry(&true) + .entry(&format_args!("{}/{}", 10, 20)) + .finish_non_exhaustive() + } + } + + assert_eq!("{true, 10/20, ..}", format!("{Foo:?}")); + assert_eq!( + "{ + true, + 10/20, + .. +}", + format!("{Foo:#?}") + ); + } + + #[test] + fn test_nested_non_exhaustive() { + struct Foo; + + impl fmt::Debug for Foo { + fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result { + fmt.debug_set() + .entry(&true) + .entry(&format_args!("{}/{}", 10, 20)) + .finish_non_exhaustive() + } + } + + struct Bar; + + impl fmt::Debug for Bar { + fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result { + fmt.debug_set().entry(&Foo).entry(&"world").finish_non_exhaustive() + } + } + + assert_eq!(r#"{{true, 10/20, ..}, "world", ..}"#, format!("{Bar:?}")); + assert_eq!( + r#"{ + { + true, + 10/20, + .. + }, + "world", + .. }"#, format!("{Bar:#?}") ); @@ -643,6 +887,80 @@ mod debug_list { 10/20, ], "world", +]"#, + format!("{Bar:#?}") + ); + } + + #[test] + fn test_empty_non_exhaustive() { + struct Foo; + + impl fmt::Debug for Foo { + fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result { + fmt.debug_list().finish_non_exhaustive() + } + } + + assert_eq!("[..]", format!("{Foo:?}")); + assert_eq!("[..]", format!("{Foo:#?}")); + } + + #[test] + fn test_multiple_non_exhaustive() { + struct Foo; + + impl fmt::Debug for Foo { + fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result { + fmt.debug_list() + .entry(&true) + .entry(&format_args!("{}/{}", 10, 20)) + .finish_non_exhaustive() + } + } + + assert_eq!("[true, 10/20, ..]", format!("{Foo:?}")); + assert_eq!( + "[ + true, + 10/20, + .. +]", + format!("{Foo:#?}") + ); + } + + #[test] + fn test_nested_non_exhaustive() { + struct Foo; + + impl fmt::Debug for Foo { + fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result { + fmt.debug_list() + .entry(&true) + .entry(&format_args!("{}/{}", 10, 20)) + .finish_non_exhaustive() + } + } + + struct Bar; + + impl fmt::Debug for Bar { + fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result { + fmt.debug_list().entry(&Foo).entry(&"world").finish_non_exhaustive() + } + } + + assert_eq!(r#"[[true, 10/20, ..], "world", ..]"#, format!("{Bar:?}")); + assert_eq!( + r#"[ + [ + true, + 10/20, + .. + ], + "world", + .. ]"#, format!("{Bar:#?}") ); diff --git a/library/core/tests/lib.rs b/library/core/tests/lib.rs index 83a615fcd8be3..0f6ba7e4c66cb 100644 --- a/library/core/tests/lib.rs +++ b/library/core/tests/lib.rs @@ -29,6 +29,7 @@ #![feature(core_io_borrowed_buf)] #![feature(core_private_bignum)] #![feature(core_private_diy_float)] +#![feature(debug_more_non_exhaustive)] #![feature(dec2flt)] #![feature(duration_consts_float)] #![feature(duration_constants)]