Improve heuristics for determining whether eager of lazy evaluation i…

…s preferred
rust-lang · Sep 5, 2021 · a5ae777 · a5ae777
1 parent cde7e6b
commit a5ae777
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Showing 15 changed files with 578 additions and 176 deletions.
diff --git a/clippy_lints/src/functions/too_many_lines.rs b/clippy_lints/src/functions/too_many_lines.rs
@@ -56,8 +56,8 @@ pub(super) fn check_fn(
                     continue;
                 }
             } else {
-                let multi_idx = line.find("/*").unwrap_or_else(|| line.len());
-                let single_idx = line.find("//").unwrap_or_else(|| line.len());
+                let multi_idx = line.find("/*").unwrap_or(line.len());
+                let single_idx = line.find("//").unwrap_or(line.len());
                 code_in_line |= multi_idx > 0 && single_idx > 0;
                 // Implies multi_idx is below line.len()
                 if multi_idx < single_idx {

diff --git a/clippy_lints/src/manual_map.rs b/clippy_lints/src/manual_map.rs
@@ -115,7 +115,7 @@ impl LateLintPass<'_> for ManualMap {
 
             // Determine which binding mode to use.
             let explicit_ref = some_pat.contains_explicit_ref_binding();
-            let binding_ref = explicit_ref.or_else(|| (ty_ref_count != pat_ref_count).then(|| ty_mutability));
+            let binding_ref = explicit_ref.or((ty_ref_count != pat_ref_count).then(|| ty_mutability));
 
             let as_ref_str = match binding_ref {
                 Some(Mutability::Mut) => ".as_mut()",

diff --git a/clippy_lints/src/methods/from_iter_instead_of_collect.rs b/clippy_lints/src/methods/from_iter_instead_of_collect.rs
@@ -69,7 +69,7 @@ fn extract_turbofish(cx: &LateContext<'_>, expr: &hir::Expr<'_>, ty: Ty<'tcx>) -
                         // i.e.: 2 wildcards in `std::collections::BTreeMap<&i32, &char>`
                         let ty_str = ty.to_string();
                         let start = ty_str.find('<').unwrap_or(0);
-                        let end = ty_str.find('>').unwrap_or_else(|| ty_str.len());
+                        let end = ty_str.find('>').unwrap_or(ty_str.len());
                         let nb_wildcard = ty_str[start..end].split(',').count();
                         let wildcards = format!("_{}", ", _".repeat(nb_wildcard - 1));
                         format!("{}<{}>", elements.join("::"), wildcards)

diff --git a/clippy_lints/src/methods/or_fun_call.rs b/clippy_lints/src/methods/or_fun_call.rs
@@ -1,5 +1,5 @@
 use clippy_utils::diagnostics::span_lint_and_sugg;
-use clippy_utils::eager_or_lazy::is_lazyness_candidate;
+use clippy_utils::eager_or_lazy::switch_to_lazy_eval;
 use clippy_utils::is_trait_item;
 use clippy_utils::source::{snippet, snippet_with_applicability, snippet_with_macro_callsite};
 use clippy_utils::ty::implements_trait;
@@ -114,7 +114,7 @@ pub(super) fn check<'tcx>(
         if_chain! {
             if KNOW_TYPES.iter().any(|k| k.2.contains(&name));
 
-            if is_lazyness_candidate(cx, arg);
+            if switch_to_lazy_eval(cx, arg);
             if !contains_return(arg);
 
             let self_ty = cx.typeck_results().expr_ty(self_expr);

diff --git a/clippy_lints/src/methods/unnecessary_lazy_eval.rs b/clippy_lints/src/methods/unnecessary_lazy_eval.rs
@@ -30,7 +30,7 @@ pub(super) fn check<'tcx>(
                 return;
             }
 
-            if eager_or_lazy::is_eagerness_candidate(cx, body_expr) {
+            if eager_or_lazy::switch_to_eager_eval(cx, body_expr) {
                 let msg = if is_option {
                     "unnecessary closure used to substitute value for `Option::None`"
                 } else {

diff --git a/clippy_lints/src/option_if_let_else.rs b/clippy_lints/src/option_if_let_else.rs
@@ -141,7 +141,7 @@ fn detect_option_if_let_else<'tcx>(
             let capture_mut = if bind_annotation == &BindingAnnotation::Mutable { "mut " } else { "" };
             let some_body = extract_body_from_arm(&arms[0])?;
             let none_body = extract_body_from_arm(&arms[1])?;
-            let method_sugg = if eager_or_lazy::is_eagerness_candidate(cx, none_body) { "map_or" } else { "map_or_else" };
+            let method_sugg = if eager_or_lazy::switch_to_eager_eval(cx, none_body) { "map_or" } else { "map_or_else" };
             let capture_name = id.name.to_ident_string();
             let (as_ref, as_mut) = match &cond_expr.kind {
                 ExprKind::AddrOf(_, Mutability::Not, _) => (true, false),

diff --git a/clippy_lints/src/redundant_clone.rs b/clippy_lints/src/redundant_clone.rs
@@ -406,14 +406,12 @@ fn visit_clone_usage(cloned: mir::Local, clone: mir::Local, mir: &mir::Body<'_>,
                 )
             {
                 self.result.cloned_used = true;
-                self.result.cloned_consume_or_mutate_loc = self.result.cloned_consume_or_mutate_loc.or_else(|| {
-                    matches!(
-                        ctx,
-                        PlaceContext::NonMutatingUse(NonMutatingUseContext::Move)
-                            | PlaceContext::MutatingUse(MutatingUseContext::Borrow)
-                    )
-                    .then(|| loc)
-                });
+                self.result.cloned_consume_or_mutate_loc = self.result.cloned_consume_or_mutate_loc.or(matches!(
+                    ctx,
+                    PlaceContext::NonMutatingUse(NonMutatingUseContext::Move)
+                        | PlaceContext::MutatingUse(MutatingUseContext::Borrow)
+                )
+                .then(|| loc));
             } else if local == self.clone {
                 match ctx {
                     PlaceContext::NonMutatingUse(NonMutatingUseContext::Move)