Unnamed repository; edit this file 'description' to name the repository.
Reduce intermediate allocations while printing witnesses
| -rw-r--r-- | crates/hir-ty/src/diagnostics/expr.rs | 29 | ||||
| -rw-r--r-- | crates/hir-ty/src/diagnostics/match_check.rs | 2 |
2 files changed, 17 insertions, 14 deletions
diff --git a/crates/hir-ty/src/diagnostics/expr.rs b/crates/hir-ty/src/diagnostics/expr.rs index e9743b4dfe..8cca522aef 100644 --- a/crates/hir-ty/src/diagnostics/expr.rs +++ b/crates/hir-ty/src/diagnostics/expr.rs @@ -2,6 +2,7 @@ //! through the body using inference results: mismatched arg counts, missing //! fields, etc. +use std::fmt; use std::sync::Arc; use hir_def::{path::path, resolver::HasResolver, AdtId, AssocItemId, DefWithBodyId, HasModule}; @@ -378,6 +379,15 @@ fn missing_match_arms<'p>( witnesses: Vec<DeconstructedPat<'p>>, arms: &[MatchArm], ) -> String { + struct DisplayWitness<'a, 'p>(&'a DeconstructedPat<'p>, &'a MatchCheckCtx<'a, 'p>); + impl<'a, 'p> fmt::Display for DisplayWitness<'a, 'p> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + let DisplayWitness(witness, cx) = *self; + let pat = witness.to_pat(cx); + write!(f, "{}", pat.display(cx.db)) + } + } + let non_empty_enum = match scrut_ty.as_adt() { Some((AdtId::EnumId(e), _)) => !cx.db.enum_data(e).variants.is_empty(), _ => false, @@ -385,25 +395,18 @@ fn missing_match_arms<'p>( if arms.is_empty() && !non_empty_enum { format!("type `{}` is non-empty", scrut_ty.display(cx.db)) } else { + let pat_display = |witness| DisplayWitness(witness, cx); const LIMIT: usize = 3; match &*witnesses { - [witness] => format!("`{}` not covered", witness.to_pat(&cx).display(cx.db)), + [witness] => format!("`{}` not covered", pat_display(witness)), [head @ .., tail] if head.len() < LIMIT => { - let head: Vec<_> = head.iter().map(|w| w.to_pat(cx)).collect(); - format!( - "`{}` and `{}` not covered", - head.iter().map(|p| p.display(cx.db)).join("`, `"), - tail.to_pat(&cx).display(cx.db) - ) + let head = head.iter().map(pat_display); + format!("`{}` and `{}` not covered", head.format("`, `"), pat_display(tail)) } _ => { let (head, tail) = witnesses.split_at(LIMIT); - let head: Vec<_> = head.iter().map(|w| w.to_pat(cx)).collect(); - format!( - "`{}` and {} more not covered", - head.iter().map(|p| p.display(cx.db)).join("`, `"), - tail.len() - ) + let head = head.iter().map(pat_display); + format!("`{}` and {} more not covered", head.format("`, `"), tail.len()) } } } diff --git a/crates/hir-ty/src/diagnostics/match_check.rs b/crates/hir-ty/src/diagnostics/match_check.rs index 276246f266..61cab7be03 100644 --- a/crates/hir-ty/src/diagnostics/match_check.rs +++ b/crates/hir-ty/src/diagnostics/match_check.rs @@ -400,7 +400,7 @@ impl<F> HirDisplay for WriteWith<F> where F: Fn(&mut HirFormatter) -> Result<(), HirDisplayError>, { - fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> { + fn hir_fmt(&self, f: &mut HirFormatter<'_>) -> Result<(), HirDisplayError> { (self.0)(f) } } |