From 4d73ccaa9419b393b9c94f977ec0e158897feeb3 Mon Sep 17 00:00:00 2001 From: Haraman Johal Date: Tue, 15 Sep 2020 00:20:31 +0100 Subject: [PATCH 1/2] clarify margin of error in wording of float comparison operator lint messages --- clippy_lints/src/misc.rs | 6 +++--- tests/ui/float_cmp.stderr | 22 +++++++++++----------- tests/ui/float_cmp_const.stderr | 30 +++++++++++++++--------------- 3 files changed, 29 insertions(+), 29 deletions(-) diff --git a/clippy_lints/src/misc.rs b/clippy_lints/src/misc.rs index d4a50dd9013..81e6214f143 100644 --- a/clippy_lints/src/misc.rs +++ b/clippy_lints/src/misc.rs @@ -411,16 +411,16 @@ impl<'tcx> LateLintPass<'tcx> for MiscLints { if !is_comparing_arrays { diag.span_suggestion( expr.span, - "consider comparing them within some error", + "consider comparing them within some margin of error", format!( - "({}).abs() {} error", + "({}).abs() {} error_margin", lhs - rhs, if op == BinOpKind::Eq { '<' } else { '>' } ), Applicability::HasPlaceholders, // snippet ); } - diag.note("`f32::EPSILON` and `f64::EPSILON` are available for the `error`"); + diag.note("`f32::EPSILON` and `f64::EPSILON` are available for the `error_margin`"); }); } else if op == BinOpKind::Rem && is_integer_const(cx, right, 1) { span_lint(cx, MODULO_ONE, expr.span, "any number modulo 1 will be 0"); diff --git a/tests/ui/float_cmp.stderr b/tests/ui/float_cmp.stderr index 2d454e8e70d..f7c380fc915 100644 --- a/tests/ui/float_cmp.stderr +++ b/tests/ui/float_cmp.stderr @@ -2,34 +2,34 @@ error: strict comparison of `f32` or `f64` --> $DIR/float_cmp.rs:65:5 | LL | ONE as f64 != 2.0; - | ^^^^^^^^^^^^^^^^^ help: consider comparing them within some error: `(ONE as f64 - 2.0).abs() > error` + | ^^^^^^^^^^^^^^^^^ help: consider comparing them within some margin of error: `(ONE as f64 - 2.0).abs() > error_margin` | = note: `-D clippy::float-cmp` implied by `-D warnings` - = note: `f32::EPSILON` and `f64::EPSILON` are available for the `error` + = note: `f32::EPSILON` and `f64::EPSILON` are available for the `error_margin` error: strict comparison of `f32` or `f64` --> $DIR/float_cmp.rs:70:5 | LL | x == 1.0; - | ^^^^^^^^ help: consider comparing them within some error: `(x - 1.0).abs() < error` + | ^^^^^^^^ help: consider comparing them within some margin of error: `(x - 1.0).abs() < error_margin` | - = note: `f32::EPSILON` and `f64::EPSILON` are available for the `error` + = note: `f32::EPSILON` and `f64::EPSILON` are available for the `error_margin` error: strict comparison of `f32` or `f64` --> $DIR/float_cmp.rs:73:5 | LL | twice(x) != twice(ONE as f64); - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider comparing them within some error: `(twice(x) - twice(ONE as f64)).abs() > error` + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider comparing them within some margin of error: `(twice(x) - twice(ONE as f64)).abs() > error_margin` | - = note: `f32::EPSILON` and `f64::EPSILON` are available for the `error` + = note: `f32::EPSILON` and `f64::EPSILON` are available for the `error_margin` error: strict comparison of `f32` or `f64` --> $DIR/float_cmp.rs:93:5 | LL | NON_ZERO_ARRAY[i] == NON_ZERO_ARRAY[j]; - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider comparing them within some error: `(NON_ZERO_ARRAY[i] - NON_ZERO_ARRAY[j]).abs() < error` + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider comparing them within some margin of error: `(NON_ZERO_ARRAY[i] - NON_ZERO_ARRAY[j]).abs() < error_margin` | - = note: `f32::EPSILON` and `f64::EPSILON` are available for the `error` + = note: `f32::EPSILON` and `f64::EPSILON` are available for the `error_margin` error: strict comparison of `f32` or `f64` arrays --> $DIR/float_cmp.rs:98:5 @@ -37,15 +37,15 @@ error: strict comparison of `f32` or `f64` arrays LL | a1 == a2; | ^^^^^^^^ | - = note: `f32::EPSILON` and `f64::EPSILON` are available for the `error` + = note: `f32::EPSILON` and `f64::EPSILON` are available for the `error_margin` error: strict comparison of `f32` or `f64` --> $DIR/float_cmp.rs:99:5 | LL | a1[0] == a2[0]; - | ^^^^^^^^^^^^^^ help: consider comparing them within some error: `(a1[0] - a2[0]).abs() < error` + | ^^^^^^^^^^^^^^ help: consider comparing them within some margin of error: `(a1[0] - a2[0]).abs() < error_margin` | - = note: `f32::EPSILON` and `f64::EPSILON` are available for the `error` + = note: `f32::EPSILON` and `f64::EPSILON` are available for the `error_margin` error: aborting due to 6 previous errors diff --git a/tests/ui/float_cmp_const.stderr b/tests/ui/float_cmp_const.stderr index 19dc4a284b7..5d0455363e8 100644 --- a/tests/ui/float_cmp_const.stderr +++ b/tests/ui/float_cmp_const.stderr @@ -2,58 +2,58 @@ error: strict comparison of `f32` or `f64` constant --> $DIR/float_cmp_const.rs:20:5 | LL | 1f32 == ONE; - | ^^^^^^^^^^^ help: consider comparing them within some error: `(1f32 - ONE).abs() < error` + | ^^^^^^^^^^^ help: consider comparing them within some margin of error: `(1f32 - ONE).abs() < error_margin` | = note: `-D clippy::float-cmp-const` implied by `-D warnings` - = note: `f32::EPSILON` and `f64::EPSILON` are available for the `error` + = note: `f32::EPSILON` and `f64::EPSILON` are available for the `error_margin` error: strict comparison of `f32` or `f64` constant --> $DIR/float_cmp_const.rs:21:5 | LL | TWO == ONE; - | ^^^^^^^^^^ help: consider comparing them within some error: `(TWO - ONE).abs() < error` + | ^^^^^^^^^^ help: consider comparing them within some margin of error: `(TWO - ONE).abs() < error_margin` | - = note: `f32::EPSILON` and `f64::EPSILON` are available for the `error` + = note: `f32::EPSILON` and `f64::EPSILON` are available for the `error_margin` error: strict comparison of `f32` or `f64` constant --> $DIR/float_cmp_const.rs:22:5 | LL | TWO != ONE; - | ^^^^^^^^^^ help: consider comparing them within some error: `(TWO - ONE).abs() > error` + | ^^^^^^^^^^ help: consider comparing them within some margin of error: `(TWO - ONE).abs() > error_margin` | - = note: `f32::EPSILON` and `f64::EPSILON` are available for the `error` + = note: `f32::EPSILON` and `f64::EPSILON` are available for the `error_margin` error: strict comparison of `f32` or `f64` constant --> $DIR/float_cmp_const.rs:23:5 | LL | ONE + ONE == TWO; - | ^^^^^^^^^^^^^^^^ help: consider comparing them within some error: `(ONE + ONE - TWO).abs() < error` + | ^^^^^^^^^^^^^^^^ help: consider comparing them within some margin of error: `(ONE + ONE - TWO).abs() < error_margin` | - = note: `f32::EPSILON` and `f64::EPSILON` are available for the `error` + = note: `f32::EPSILON` and `f64::EPSILON` are available for the `error_margin` error: strict comparison of `f32` or `f64` constant --> $DIR/float_cmp_const.rs:25:5 | LL | x as f32 == ONE; - | ^^^^^^^^^^^^^^^ help: consider comparing them within some error: `(x as f32 - ONE).abs() < error` + | ^^^^^^^^^^^^^^^ help: consider comparing them within some margin of error: `(x as f32 - ONE).abs() < error_margin` | - = note: `f32::EPSILON` and `f64::EPSILON` are available for the `error` + = note: `f32::EPSILON` and `f64::EPSILON` are available for the `error_margin` error: strict comparison of `f32` or `f64` constant --> $DIR/float_cmp_const.rs:28:5 | LL | v == ONE; - | ^^^^^^^^ help: consider comparing them within some error: `(v - ONE).abs() < error` + | ^^^^^^^^ help: consider comparing them within some margin of error: `(v - ONE).abs() < error_margin` | - = note: `f32::EPSILON` and `f64::EPSILON` are available for the `error` + = note: `f32::EPSILON` and `f64::EPSILON` are available for the `error_margin` error: strict comparison of `f32` or `f64` constant --> $DIR/float_cmp_const.rs:29:5 | LL | v != ONE; - | ^^^^^^^^ help: consider comparing them within some error: `(v - ONE).abs() > error` + | ^^^^^^^^ help: consider comparing them within some margin of error: `(v - ONE).abs() > error_margin` | - = note: `f32::EPSILON` and `f64::EPSILON` are available for the `error` + = note: `f32::EPSILON` and `f64::EPSILON` are available for the `error_margin` error: strict comparison of `f32` or `f64` constant arrays --> $DIR/float_cmp_const.rs:61:5 @@ -61,7 +61,7 @@ error: strict comparison of `f32` or `f64` constant arrays LL | NON_ZERO_ARRAY == NON_ZERO_ARRAY2; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | - = note: `f32::EPSILON` and `f64::EPSILON` are available for the `error` + = note: `f32::EPSILON` and `f64::EPSILON` are available for the `error_margin` error: aborting due to 8 previous errors From 16b6cebaa67655a793d90d296c03e2c5496ec4ce Mon Sep 17 00:00:00 2001 From: Haraman Johal Date: Tue, 15 Sep 2020 17:29:41 +0100 Subject: [PATCH 2/2] update lint docs --- clippy_lints/src/misc.rs | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/clippy_lints/src/misc.rs b/clippy_lints/src/misc.rs index 81e6214f143..67a3685fd0d 100644 --- a/clippy_lints/src/misc.rs +++ b/clippy_lints/src/misc.rs @@ -99,11 +99,11 @@ declare_clippy_lint! { /// if y != x {} // where both are floats /// /// // Good - /// let error = f64::EPSILON; // Use an epsilon for comparison + /// let error_margin = f64::EPSILON; // Use an epsilon for comparison /// // Or, if Rust <= 1.42, use `std::f64::EPSILON` constant instead. - /// // let error = std::f64::EPSILON; - /// if (y - 1.23f64).abs() < error { } - /// if (y - x).abs() > error { } + /// // let error_margin = std::f64::EPSILON; + /// if (y - 1.23f64).abs() < error_margin { } + /// if (y - x).abs() > error_margin { } /// ``` pub FLOAT_CMP, correctness, @@ -242,10 +242,10 @@ declare_clippy_lint! { /// if x == ONE { } // where both are floats /// /// // Good - /// let error = f64::EPSILON; // Use an epsilon for comparison + /// let error_margin = f64::EPSILON; // Use an epsilon for comparison /// // Or, if Rust <= 1.42, use `std::f64::EPSILON` constant instead. - /// // let error = std::f64::EPSILON; - /// if (x - ONE).abs() < error { } + /// // let error_margin = std::f64::EPSILON; + /// if (x - ONE).abs() < error_margin { } /// ``` pub FLOAT_CMP_CONST, restriction,