Merge pull request #2504 from flip1995/lit_float_repr

Fix unreadable_literal lint for scientific float notation

clippy_lints/src/literal_representation.rs

@@ -134,7 +134,7 @@ impl<'a> DigitInfo<'a> {
 
         let mut last_d = '\0';
         for (d_idx, d) in sans_prefix.char_indices() {
-            if !float && (d == 'i' || d == 'u') || float && d == 'f' {
+            if !float && (d == 'i' || d == 'u') || float && (d == 'f' || d == 'e' || d == 'E') {
                 let suffix_start = if last_d == '_' { d_idx - 1 } else { d_idx };
                 let (digits, suffix) = sans_prefix.split_at(suffix_start);
                 return Self {
@@ -285,9 +285,10 @@ impl EarlyLintPass for LiteralDigitGrouping {
 
 impl LiteralDigitGrouping {
     fn check_lit(&self, cx: &EarlyContext, lit: &Lit) {
+        match lit.node {
+            LitKind::Int(..) => {
                 // Lint integral literals.
                 if_chain! {
-            if let LitKind::Int(..) = lit.node;
                     if let Some(src) = snippet_opt(cx, lit.span);
                     if let Some(firstch) = src.chars().next();
                     if char::to_digit(firstch, 10).is_some();
@@ -298,10 +299,10 @@ impl LiteralDigitGrouping {
                         });
                     }
                 }
-
+            },
+            LitKind::Float(..) | LitKind::FloatUnsuffixed(..) => {
                 // Lint floating-point literals.
                 if_chain! {
-            if let LitKind::Float(..) = lit.node;
                     if let Some(src) = snippet_opt(cx, lit.span);
                     if let Some(firstch) = src.chars().next();
                     if char::to_digit(firstch, 10).is_some();
@@ -340,6 +341,9 @@ impl LiteralDigitGrouping {
                         .map_err(|warning_type| warning_type.display(&digit_info.grouping_hint(), cx, &lit.span));
                     }
                 }
+            },
+            _ => (),
+        }
     }
 
     /// Given the sizes of the digit groups of both integral and fractional

tests/ui/approx_const.rs

@@ -2,7 +2,7 @@
 
 
 #[warn(approx_constant)]
-#[allow(unused, shadow_unrelated, similar_names)]
+#[allow(unused, shadow_unrelated, similar_names, unreadable_literal)]
 fn main() {
     let my_e = 2.7182;
     let almost_e = 2.718;

tests/ui/unreadable_literal.rs

@@ -5,4 +5,6 @@
 fn main() {
     let good = (0b1011_i64, 0o1_234_u32, 0x1_234_567, 1_2345_6789, 1234_f32, 1_234.12_f32, 1_234.123_f32, 1.123_4_f32);
     let bad = (0b10110_i64, 0x12345678901_usize, 12345_f32, 1.23456_f32);
+    let good_sci = 1.1234e1;
+    let bad_sci = 1.12345e1;
 }

tests/ui/unreadable_literal.stderr

@@ -24,5 +24,11 @@ error: long literal lacking separators
 7 |     let bad = (0b10110_i64, 0x12345678901_usize, 12345_f32, 1.23456_f32);
   |                                                             ^^^^^^^^^^^ help: consider: `1.234_56_f32`
 
-error: aborting due to 4 previous errors
+error: long literal lacking separators
+ --> $DIR/unreadable_literal.rs:9:19
+  |
+9 |     let bad_sci = 1.12345e1;
+  |                   ^^^^^^^^^ help: consider: `1.123_45e1`
+
+error: aborting due to 5 previous errors