Move FuzzyEq trait into core::cmp and rename it to 'ApproxEq'

Author: brendanzab

src/libcore/cmp.rs

@@ -66,6 +66,13 @@ 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/libcore/num/f32.rs

@@ -210,6 +210,22 @@ impl Eq for f32 {
     fn ne(&self, other: &f32) -> bool { (*self) != (*other) }
 }
 
+#[cfg(notest)]
+impl ApproxEq<f32> for f32 {
+    #[inline(always)]
+    fn approx_epsilon() -> f32 { 1.0e-6 }
+
+    #[inline(always)]
+    fn approx_eq(&self, other: &f32) -> bool {
+        self.approx_eq_eps(other, &ApproxEq::approx_epsilon::<f32, f32>())
+    }
+
+    #[inline(always)]
+    fn approx_eq_eps(&self, other: &f32, approx_epsilon: &f32) -> bool {
+        (*self - *other).abs() < *approx_epsilon
+    }
+}
+
 #[cfg(notest)]
 impl Ord for f32 {
     #[inline(always)]
@@ -974,6 +990,15 @@ 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() {
         assert_eq!(Primitive::bits::<f32>(), sys::size_of::<f32>() * 8);

src/libcore/num/f64.rs

@@ -233,6 +233,22 @@ impl Eq for f64 {
     fn ne(&self, other: &f64) -> bool { (*self) != (*other) }
 }
 
+#[cfg(notest)]
+impl ApproxEq<f64> for f64 {
+    #[inline(always)]
+    fn approx_epsilon() -> f64 { 1.0e-6 }
+
+    #[inline(always)]
+    fn approx_eq(&self, other: &f64) -> bool {
+        self.approx_eq_eps(other, &ApproxEq::approx_epsilon::<f64, f64>())
+    }
+
+    #[inline(always)]
+    fn approx_eq_eps(&self, other: &f64, approx_epsilon: &f64) -> bool {
+        (*self - *other).abs() < *approx_epsilon
+    }
+}
+
 #[cfg(notest)]
 impl Ord for f64 {
     #[inline(always)]
@@ -1022,6 +1038,15 @@ 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() {
         assert_eq!(Primitive::bits::<f64>(), sys::size_of::<f64>() * 8);

src/libcore/num/float.rs

@@ -371,6 +371,22 @@ impl Eq for float {
     fn ne(&self, other: &float) -> bool { (*self) != (*other) }
 }
 
+#[cfg(notest)]
+impl ApproxEq<float> for float {
+    #[inline(always)]
+    fn approx_epsilon() -> float { 1.0e-6 }
+
+    #[inline(always)]
+    fn approx_eq(&self, other: &float) -> bool {
+        self.approx_eq_eps(other, &ApproxEq::approx_epsilon::<float, float>())
+    }
+
+    #[inline(always)]
+    fn approx_eq_eps(&self, other: &float, approx_epsilon: &float) -> bool {
+        (*self - *other).abs() < *approx_epsilon
+    }
+}
+
 #[cfg(notest)]
 impl Ord for float {
     #[inline(always)]
@@ -985,6 +1001,15 @@ mod tests {
         assert!(!NaN.is_negative());
     }
 
+    #[test]
+    fn test_approx_eq() {
+        assert!(1.0f.approx_eq(&1f));
+        assert!(0.9999999f.approx_eq(&1f));
+        assert!(1.000001f.approx_eq_eps(&1f, &1.0e-5));
+        assert!(1.0000001f.approx_eq_eps(&1f, &1.0e-6));
+        assert!(!1.0000001f.approx_eq_eps(&1f, &1.0e-7));
+    }
+
     #[test]
     fn test_primitive() {
         assert_eq!(Primitive::bits::<float>(), sys::size_of::<float>() * 8);

src/libcore/num/num.rs

@@ -9,7 +9,7 @@
 // except according to those terms.
 
 //! An interface for numeric types
-use cmp::{Eq, Ord};
+use cmp::{Eq, ApproxEq, Ord};
 use ops::{Add, Sub, Mul, Div, Rem, Neg};
 use ops::{Not, BitAnd, BitOr, BitXor, Shl, Shr};
 use option::Option;
@@ -240,7 +240,8 @@ pub trait Int: Integer
 ///
 pub trait Float: Real
                + Signed
-               + Primitive {
+               + Primitive
+               + ApproxEq<Self> {
     // FIXME (#5527): These should be associated constants
     fn NaN() -> Self;
     fn infinity() -> Self;

src/libcore/prelude.rs

@@ -28,7 +28,7 @@ pub use io::{print, println};
 /* Reexported types and traits */
 
 pub use clone::Clone;
-pub use cmp::{Eq, Ord, TotalEq, TotalOrd, Ordering, Less, Equal, Greater, Equiv};
+pub use cmp::{Eq, ApproxEq, Ord, TotalEq, TotalOrd, Ordering, Less, Equal, Greater, Equiv};
 pub use container::{Container, Mutable, Map, Set};
 pub use hash::Hash;
 pub use old_iter::{BaseIter, ReverseIter, MutableIter, ExtendedIter, EqIter};

src/libstd/cmp.rs

@@ -86,7 +86,6 @@ pub mod term;
 pub mod time;
 pub mod arena;
 pub mod par;
-pub mod cmp;
 pub mod base64;
 pub mod rl;
 pub mod workcache;

src/libstd/std.rc

@@ -10,10 +10,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-extern mod std;
-
-use std::cmp::FuzzyEq;
-
 mod rusti {
     #[abi = "rust-intrinsic"]
     pub extern "rust-intrinsic" {
@@ -54,44 +50,44 @@ pub fn main() {
     unsafe {
         use rusti::*;
 
-        assert!((sqrtf32(64f32).fuzzy_eq(&8f32)));
-        assert!((sqrtf64(64f64).fuzzy_eq(&8f64)));
+        assert!((sqrtf32(64f32).approx_eq(&8f32)));
+        assert!((sqrtf64(64f64).approx_eq(&8f64)));
 
-        assert!((powif32(25f32, -2i32).fuzzy_eq(&0.0016f32)));
-        assert!((powif64(23.2f64, 2i32).fuzzy_eq(&538.24f64)));
+        assert!((powif32(25f32, -2i32).approx_eq(&0.0016f32)));
+        assert!((powif64(23.2f64, 2i32).approx_eq(&538.24f64)));
 
-        assert!((sinf32(0f32).fuzzy_eq(&0f32)));
-        assert!((sinf64(f64::consts::pi / 2f64).fuzzy_eq(&1f64)));
+        assert!((sinf32(0f32).approx_eq(&0f32)));
+        assert!((sinf64(f64::consts::pi / 2f64).approx_eq(&1f64)));
 
-        assert!((cosf32(0f32).fuzzy_eq(&1f32)));
-        assert!((cosf64(f64::consts::pi * 2f64).fuzzy_eq(&1f64)));
+        assert!((cosf32(0f32).approx_eq(&1f32)));
+        assert!((cosf64(f64::consts::pi * 2f64).approx_eq(&1f64)));
 
-        assert!((powf32(25f32, -2f32).fuzzy_eq(&0.0016f32)));
-        assert!((powf64(400f64, 0.5f64).fuzzy_eq(&20f64)));
+        assert!((powf32(25f32, -2f32).approx_eq(&0.0016f32)));
+        assert!((powf64(400f64, 0.5f64).approx_eq(&20f64)));
 
-        assert!((fabsf32(expf32(1f32) - f32::consts::e).fuzzy_eq(&0f32)));
-        assert!((expf64(1f64).fuzzy_eq(&f64::consts::e)));
+        assert!((fabsf32(expf32(1f32) - f32::consts::e).approx_eq(&0f32)));
+        assert!((expf64(1f64).approx_eq(&f64::consts::e)));
 
-        assert!((exp2f32(10f32).fuzzy_eq(&1024f32)));
-        assert!((exp2f64(50f64).fuzzy_eq(&1125899906842624f64)));
+        assert!((exp2f32(10f32).approx_eq(&1024f32)));
+        assert!((exp2f64(50f64).approx_eq(&1125899906842624f64)));
 
-        assert!((fabsf32(logf32(f32::consts::e) - 1f32).fuzzy_eq(&0f32)));
-        assert!((logf64(1f64).fuzzy_eq(&0f64)));
+        assert!((fabsf32(logf32(f32::consts::e) - 1f32).approx_eq(&0f32)));
+        assert!((logf64(1f64).approx_eq(&0f64)));
 
-        assert!((log10f32(10f32).fuzzy_eq(&1f32)));
-        assert!((log10f64(f64::consts::e).fuzzy_eq(&f64::consts::log10_e)));
+        assert!((log10f32(10f32).approx_eq(&1f32)));
+        assert!((log10f64(f64::consts::e).approx_eq(&f64::consts::log10_e)));
 
-        assert!((log2f32(8f32).fuzzy_eq(&3f32)));
-        assert!((log2f64(f64::consts::e).fuzzy_eq(&f64::consts::log2_e)));
+        assert!((log2f32(8f32).approx_eq(&3f32)));
+        assert!((log2f64(f64::consts::e).approx_eq(&f64::consts::log2_e)));
 
-        assert!((fmaf32(1.0f32, 2.0f32, 5.0f32).fuzzy_eq(&7.0f32)));
-        assert!((fmaf64(0.0f64, -2.0f64, f64::consts::e).fuzzy_eq(&f64::consts::e)));
+        assert!((fmaf32(1.0f32, 2.0f32, 5.0f32).approx_eq(&7.0f32)));
+        assert!((fmaf64(0.0f64, -2.0f64, f64::consts::e).approx_eq(&f64::consts::e)));
 
-        assert!((fabsf32(-1.0f32).fuzzy_eq(&1.0f32)));
-        assert!((fabsf64(34.2f64).fuzzy_eq(&34.2f64)));
+        assert!((fabsf32(-1.0f32).approx_eq(&1.0f32)));
+        assert!((fabsf64(34.2f64).approx_eq(&34.2f64)));
 
-        assert!((floorf32(3.8f32).fuzzy_eq(&3.0f32)));
-        assert!((floorf64(-1.1f64).fuzzy_eq(&-2.0f64)));
+        assert!((floorf32(3.8f32).approx_eq(&3.0f32)));
+        assert!((floorf64(-1.1f64).approx_eq(&-2.0f64)));
 
         // Causes linker error
         // undefined reference to llvm.ceil.f32/64

src/test/run-pass/intrinsics-math.rs

@@ -14,11 +14,10 @@ extern mod std;
 
 use core::cmp::{Eq, Ord};
 use core::num::NumCast::from;
-use std::cmp::FuzzyEq;
 
 pub trait NumExt: Num + NumCast + Eq + Ord {}
 
-pub trait FloatExt: NumExt + FuzzyEq<Self> {}
+pub trait FloatExt: NumExt + ApproxEq<Self> {}
 
 fn greater_than_one<T:NumExt>(n: &T) -> bool { *n > from(1) }
 fn greater_than_one_float<T:FloatExt>(n: &T) -> bool { *n > from(1) }

src/test/run-pass/trait-inheritance-num.rs

@@ -16,7 +16,6 @@ extern mod std;
 
 use core::cmp::{Eq, Ord};
 use core::num::NumCast::from;
-use std::cmp::FuzzyEq;
 
 pub trait TypeExt {}
 
@@ -94,7 +93,7 @@ impl IntegerExt for i64 {}
 impl IntegerExt for int {}
 
 
-pub trait FloatExt: NumExt + FuzzyEq<Self> {}
+pub trait FloatExt: NumExt + ApproxEq<Self> {}
 
 impl FloatExt for f32 {}
 impl FloatExt for f64 {}