use proper words in help message for floating point

[rust.git] / compiler / rustc_typeck / src / check / expr.rs

diff --git a/compiler/rustc_typeck/src/check/expr.rs b/compiler/rustc_typeck/src/check/expr.rs
index a685add7f56a61903ab96c022c45e16d1bfdcbed..51182d2a40d2844b5563d4930a5366c5d2e8b639 100644 (file)
--- a/compiler/rustc_typeck/src/check/expr.rs
+++ b/compiler/rustc_typeck/src/check/expr.rs
@@ -2159,7 +2159,7 @@ fn check_field(
                 E0610,
                 "`{expr_t}` is a primitive type and therefore doesn't have fields",
             );
-            let is_valid_suffix = |field: String| {
+            let is_valid_suffix = |field: &str| {
                 if field == "f32" || field == "f64" {
                     return true;
                 }
@@ -2184,20 +2184,39 @@ fn check_field(
                 let suffix = chars.collect::<String>();
                 suffix.is_empty() || suffix == "f32" || suffix == "f64"
             };
+            let maybe_partial_suffix = |field: &str| -> Option<&str> {
+                let first_chars = ['f', 'l'];
+                if field.len() >= 1
+                    && field.to_lowercase().starts_with(first_chars)
+                    && field[1..].chars().all(|c| c.is_ascii_digit())
+                {
+                    if field.to_lowercase().starts_with(['f']) { Some("f32") } else { Some("f64") }
+                } else {
+                    None
+                }
+            };
             if let ty::Infer(ty::IntVar(_)) = expr_t.kind()
                 && let ExprKind::Lit(Spanned {
                     node: ast::LitKind::Int(_, ast::LitIntType::Unsuffixed),
                     ..
                 }) = base.kind
                 && !base.span.from_expansion()
-                && is_valid_suffix(field_name)
             {
-                err.span_suggestion_verbose(
-                    field.span.shrink_to_lo(),
-                    "If the number is meant to be a floating point number, consider adding a `0` after the period",
-                    '0',
-                    Applicability::MaybeIncorrect,
-                );
+                if is_valid_suffix(&field_name) {
+                    err.span_suggestion_verbose(
+                        field.span.shrink_to_lo(),
+                        "if intended to be a floating point literal, consider adding a `0` after the period",
+                        '0',
+                        Applicability::MaybeIncorrect,
+                    );
+                } else if let Some(correct_suffix) = maybe_partial_suffix(&field_name) {
+                    err.span_suggestion_verbose(
+                        field.span,
+                        format!("if intended to be a floating point literal, consider adding a `0` after the period and a `{correct_suffix}` suffix"),
+                        format!("0{correct_suffix}"),
+                        Applicability::MaybeIncorrect,
+                    );
+                }
             }
             err.emit();
         }