auto merge of #11402 : bjz/rust/remove-approx, r=alexcrichton

This trait seems to stray too far from the mandate of a standard library as implementations may vary between use cases. Third party libraries should implement their own if they need something like it.

This closes #5316.

r? @alexcrichton, @pcwalton

Author: bors

doc/guide-testing.md

@@ -48,8 +48,7 @@ value. To run the tests in a crate, it must be compiled with the
 the resulting executable will run all the tests in the crate. A test
 is considered successful if its function returns; if the task running
 the test fails, through a call to `fail!`, a failed `check` or
-`assert`, or some other (`assert_eq`, `assert_approx_eq`, ...) means,
-then the test fails.
+`assert`, or some other (`assert_eq`, ...) means, then the test fails.
 
 When compiling a crate with the '--test' flag '--cfg test' is also
 implied, so that tests can be conditionally compiled.

src/etc/vim/syntax/rust.vim

@@ -71,7 +71,7 @@ syn keyword rustTrait Bool
 syn keyword rustTrait ToCStr
 syn keyword rustTrait Char
 syn keyword rustTrait Clone DeepClone
-syn keyword rustTrait Eq ApproxEq Ord TotalEq TotalOrd Ordering Equiv
+syn keyword rustTrait Eq Ord TotalEq TotalOrd Ordering Equiv
 syn keyword rustEnumVariant Less Equal Greater
 syn keyword rustTrait Container Mutable Map MutableMap Set MutableSet
 syn keyword rustTrait Default

src/libextra/num/complex.rs

@@ -268,7 +268,7 @@ mod test {
     #[test]
     fn test_arg() {
         fn test(c: Complex64, arg: f64) {
-            assert!(c.arg().approx_eq(&arg))
+            assert!((c.arg() - arg).abs() < 1.0e-6)
         }
         test(_1_0i, 0.0);
         test(_1_1i, 0.25 * Real::pi());

src/libextra/stats.rs

@@ -439,6 +439,14 @@ mod tests {
     use std::io;
     use std::str;
 
+    macro_rules! assert_approx_eq(
+        ($a:expr, $b:expr) => ({
+            let (a, b) = (&$a, &$b);
+            assert!((*a - *b).abs() < 1.0e-6,
+                    "{} is not approximately equal to {}", *a, *b);
+        })
+    )
+
     fn check(samples: &[f64], summ: &Summary) {
 
         let summ2 = Summary::new(samples);

src/libstd/cmp.rs

@@ -72,13 +72,6 @@ totaleq_impl!(uint)
 
 totaleq_impl!(char)
 
-/// Trait for testing approximate equality
-pub trait ApproxEq<Eps> {
-    fn approx_epsilon() -> Eps;
-    fn approx_eq(&self, other: &Self) -> bool;
-    fn approx_eq_eps(&self, other: &Self, approx_epsilon: &Eps) -> bool;
-}
-
 #[deriving(Clone, Eq)]
 pub enum Ordering { Less = -1, Equal = 0, Greater = 1 }
 

src/libstd/lib.rs

@@ -85,6 +85,7 @@ pub mod prelude;
 
 /* Primitive types */
 
+#[path = "num/float_macros.rs"] mod float_macros;
 #[path = "num/int_macros.rs"]   mod int_macros;
 #[path = "num/uint_macros.rs"]  mod uint_macros;
 

src/libstd/num/f32.rs

@@ -166,22 +166,6 @@ impl Eq for f32 {
     fn eq(&self, other: &f32) -> bool { (*self) == (*other) }
 }
 
-#[cfg(not(test))]
-impl ApproxEq<f32> for f32 {
-    #[inline]
-    fn approx_epsilon() -> f32 { 1.0e-6 }
-
-    #[inline]
-    fn approx_eq(&self, other: &f32) -> bool {
-        self.approx_eq_eps(other, &1.0e-6)
-    }
-
-    #[inline]
-    fn approx_eq_eps(&self, other: &f32, approx_epsilon: &f32) -> bool {
-        (*self - *other).abs() < *approx_epsilon
-    }
-}
-
 #[cfg(not(test))]
 impl Ord for f32 {
     #[inline]
@@ -1195,15 +1179,6 @@ mod tests {
         assert!(!NAN.is_negative());
     }
 
-    #[test]
-    fn test_approx_eq() {
-        assert!(1.0f32.approx_eq(&1f32));
-        assert!(0.9999999f32.approx_eq(&1f32));
-        assert!(1.000001f32.approx_eq_eps(&1f32, &1.0e-5));
-        assert!(1.0000001f32.approx_eq_eps(&1f32, &1.0e-6));
-        assert!(!1.0000001f32.approx_eq_eps(&1f32, &1.0e-7));
-    }
-
     #[test]
     fn test_primitive() {
         let none: Option<f32> = None;

src/libstd/num/f64.rs

@@ -189,22 +189,6 @@ impl Eq for f64 {
     fn eq(&self, other: &f64) -> bool { (*self) == (*other) }
 }
 
-#[cfg(not(test))]
-impl ApproxEq<f64> for f64 {
-    #[inline]
-    fn approx_epsilon() -> f64 { 1.0e-6 }
-
-    #[inline]
-    fn approx_eq(&self, other: &f64) -> bool {
-        self.approx_eq_eps(other, &1.0e-6)
-    }
-
-    #[inline]
-    fn approx_eq_eps(&self, other: &f64, approx_epsilon: &f64) -> bool {
-        (*self - *other).abs() < *approx_epsilon
-    }
-}
-
 #[cfg(not(test))]
 impl Ord for f64 {
     #[inline]
@@ -1246,15 +1230,6 @@ mod tests {
         assert!(!NAN.is_negative());
     }
 
-    #[test]
-    fn test_approx_eq() {
-        assert!(1.0f64.approx_eq(&1f64));
-        assert!(0.9999999f64.approx_eq(&1f64));
-        assert!(1.000001f64.approx_eq_eps(&1f64, &1.0e-5));
-        assert!(1.0000001f64.approx_eq_eps(&1f64, &1.0e-6));
-        assert!(!1.0000001f64.approx_eq_eps(&1f64, &1.0e-7));
-    }
-
     #[test]
     fn test_primitive() {
         let none: Option<f64> = None;

src/test/run-fail/assert-approx-eq-eps-macro-fail.rs renamed to src/libstd/num/float_macros.rs

@@ -1,4 +1,4 @@
-// Copyright 2013 The Rust Project Developers. See the COPYRIGHT
+// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
 // file at the top-level directory of this distribution and at
 // http://rust-lang.org/COPYRIGHT.
 //
@@ -8,7 +8,13 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// error-pattern:left: 1.0000001f64 does not approximately equal right: 1f64 with epsilon: 0.0000001f64
-pub fn main() {
-    assert_approx_eq!(1.0000001f64, 1.0f64, 1.0e-7);
-}
+#[macro_escape];
+#[doc(hidden)];
+
+macro_rules! assert_approx_eq(
+    ($a:expr, $b:expr) => ({
+        let (a, b) = (&$a, &$b);
+        assert!((*a - *b).abs() < 1.0e-6,
+                "{} is not approximately equal to {}", *a, *b);
+    })
+)

src/libstd/num/mod.rs

@@ -16,7 +16,7 @@
 #[allow(missing_doc)];
 
 use clone::{Clone, DeepClone};
-use cmp::{Eq, ApproxEq, Ord};
+use cmp::{Eq, Ord};
 use ops::{Add, Sub, Mul, Div, Rem, Neg};
 use ops::{Not, BitAnd, BitOr, BitXor, Shl, Shr};
 use option::{Option, Some, None};
@@ -138,60 +138,19 @@ pub trait Integer: Num
 /// A collection of rounding operations.
 pub trait Round {
     /// Return the largest integer less than or equal to a number.
-    ///
-    /// # Example
-    ///
-    /// ```rust
-    /// assert_approx_eq!(1.3f32.floor(), 1.0);
-    /// assert_approx_eq!((-1.3f32).floor(), -2.0);
-    /// ```
     fn floor(&self) -> Self;
 
     /// Return the smallest integer greater than or equal to a number.
-    ///
-    /// # Example
-    ///
-    /// ```rust
-    /// assert_approx_eq!(1.3f32.ceil(), 2.0);
-    /// assert_approx_eq!((-1.3f32).ceil(), -1.0);
-    /// ```
     fn ceil(&self) -> Self;
 
     /// Return the nearest integer to a number. Round half-way cases away from
     /// `0.0`.
-    ///
-    /// # Example
-    ///
-    /// ```rust
-    /// assert_approx_eq!(1.3f32.round(), 1.0);
-    /// assert_approx_eq!((-1.3f32).round(), -1.0);
-    /// assert_approx_eq!(1.5f32.round(), 2.0);
-    /// assert_approx_eq!((-1.5f32).round(), -2.0);
-    /// ```
     fn round(&self) -> Self;
 
     /// Return the integer part of a number.
-    ///
-    /// # Example
-    ///
-    /// ```rust
-    /// assert_approx_eq!(1.3f32.trunc(), 1.0);
-    /// assert_approx_eq!((-1.3f32).trunc(), -1.0);
-    /// assert_approx_eq!(1.5f32.trunc(), 1.0);
-    /// assert_approx_eq!((-1.5f32).trunc(), -1.0);
-    /// ```
     fn trunc(&self) -> Self;
 
     /// Return the fractional part of a number.
-    ///
-    /// # Example
-    ///
-    /// ```rust
-    /// assert_approx_eq!(1.3f32.fract(), 0.3);
-    /// assert_approx_eq!((-1.3f32).fract(), -0.3);
-    /// assert_approx_eq!(1.5f32.fract(), 0.5);
-    /// assert_approx_eq!((-1.5f32).fract(), -0.5);
-    /// ```
     fn fract(&self) -> Self;
 }
 
@@ -262,18 +221,7 @@ pub trait Trigonometric {
     fn atan(&self) -> Self;
 
     /// Computes the four quadrant arctangent of a number, `y`, and another
-    /// number `x`. Return value is in radians in the range [-pi, pi];
-    ///
-    /// # Example
-    ///
-    /// ```rust
-    /// use std::f32;
-    ///
-    /// let y = 3f32.sqrt();
-    /// let x = 1f32;
-    /// assert_approx_eq!(y.atan2(&x), f32::consts::PI / 3f32);
-    /// assert_approx_eq!((-y).atan2(&(-x)), - 2f32 * f32::consts::PI / 3f32);
-    /// ```
+    /// number `x`. Return value is in radians in the range [-pi, pi].
     fn atan2(&self, other: &Self) -> Self;
 
     /// Simultaneously computes the sine and cosine of the number, `x`. Returns
@@ -505,8 +453,7 @@ pub enum FPCategory {
 /// Primitive floating point numbers
 pub trait Float: Real
                + Signed
-               + Primitive
-               + ApproxEq<Self> {
+               + Primitive {
     // FIXME (#5527): These should be associated constants
     fn nan() -> Self;
     fn infinity() -> Self;

src/libstd/prelude.rs

@@ -50,7 +50,7 @@ pub use bool::Bool;
 pub use c_str::ToCStr;
 pub use char::Char;
 pub use clone::{Clone, DeepClone};
-pub use cmp::{Eq, ApproxEq, Ord, TotalEq, TotalOrd, Ordering, Less, Equal, Greater, Equiv};
+pub use cmp::{Eq, Ord, TotalEq, TotalOrd, Ordering, Less, Equal, Greater, Equiv};
 pub use container::{Container, Mutable, Map, MutableMap, Set, MutableSet};
 pub use default::Default;
 pub use from_str::FromStr;

src/libsyntax/ext/expand.rs

@@ -741,43 +741,6 @@ pub fn std_macros() -> @str {
         )
     )
 
-    macro_rules! assert_approx_eq (
-        ($given:expr , $expected:expr) => (
-            {
-                use std::cmp::ApproxEq;
-
-                let given_val = $given;
-                let expected_val = $expected;
-                // check both directions of equality....
-                if !(
-                    given_val.approx_eq(&expected_val) &&
-                    expected_val.approx_eq(&given_val)
-                ) {
-                    fail!("left: {:?} does not approximately equal right: {:?}",
-                           given_val, expected_val);
-                }
-            }
-        );
-        ($given:expr , $expected:expr , $epsilon:expr) => (
-            {
-                use std::cmp::ApproxEq;
-
-                let given_val = $given;
-                let expected_val = $expected;
-                let epsilon_val = $epsilon;
-                // check both directions of equality....
-                if !(
-                    given_val.approx_eq_eps(&expected_val, &epsilon_val) &&
-                    expected_val.approx_eq_eps(&given_val, &epsilon_val)
-                ) {
-                    fail!("left: {:?} does not approximately equal right: \
-                             {:?} with epsilon: {:?}",
-                          given_val, expected_val, epsilon_val);
-                }
-            }
-        )
-    )
-
     /// A utility macro for indicating unreachable code. It will fail if
     /// executed. This is occasionally useful to put after loops that never
     /// terminate normally, but instead directly return from a function.