clippy::complexity simplifications related to Iterators

Author: matthiaskrgr

crates/hir/src/lib.rs

@@ -213,7 +213,7 @@ impl Crate {
                 Some(TokenTree::Leaf(Leaf::Literal(Literal{ref text, ..}))) => Some(text),
                 _ => None
             }
-        }).flat_map(|t| t).next();
+        }).flatten().next();
 
         doc_url.map(|s| s.trim_matches('"').trim_end_matches('/').to_owned() + "/")
     }

crates/hir_def/src/attr.rs

@@ -638,7 +638,7 @@ fn collect_attrs(
     owner: &dyn ast::AttrsOwner,
 ) -> impl Iterator<Item = Either<ast::Attr, ast::Comment>> {
     let (inner_attrs, inner_docs) = inner_attributes(owner.syntax())
-        .map_or((None, None), |(attrs, docs)| ((Some(attrs), Some(docs))));
+        .map_or((None, None), |(attrs, docs)| (Some(attrs), Some(docs)));
 
     let outer_attrs = owner.attrs().filter(|attr| attr.excl_token().is_none());
     let attrs = outer_attrs

crates/hir_ty/src/infer/pat.rs

@@ -38,7 +38,7 @@ impl<'a> InferenceContext<'a> {
         let field_tys = def.map(|it| self.db.field_types(it)).unwrap_or_default();
         let (pre, post) = match ellipsis {
             Some(idx) => subpats.split_at(idx),
-            None => (&subpats[..], &[][..]),
+            None => (subpats, &[][..]),
         };
         let post_idx_offset = field_tys.iter().count() - post.len();
 

crates/ide/src/extend_selection.rs

@@ -263,11 +263,10 @@ fn extend_list_item(node: &SyntaxNode) -> Option<TextRange> {
     ) -> Option<SyntaxToken> {
         node.siblings_with_tokens(dir)
             .skip(1)
-            .skip_while(|node| match node {
-                NodeOrToken::Node(_) => false,
-                NodeOrToken::Token(it) => is_single_line_ws(it),
+            .find(|node| match node {
+                NodeOrToken::Node(_) => true,
+                NodeOrToken::Token(it) => !is_single_line_ws(it),
             })
-            .next()
             .and_then(|it| it.into_token())
             .filter(|node| node.kind() == delimiter_kind)
     }

crates/ide_assists/src/handlers/convert_comment_block.rs

@@ -1,5 +1,4 @@
 use itertools::Itertools;
-use std::convert::identity;
 use syntax::{
     ast::{
         self,
@@ -140,7 +139,7 @@ fn relevant_line_comments(comment: &ast::Comment) -> Vec<Comment> {
         .filter(|s| !skippable(s))
         .map(|not| not.into_token().and_then(Comment::cast).filter(same_prefix))
         .take_while(|opt_com| opt_com.is_some())
-        .filter_map(identity)
+        .flatten()
         .skip(1); // skip the first element so we don't duplicate it in next_comments
 
     let next_comments = comment
@@ -149,7 +148,7 @@ fn relevant_line_comments(comment: &ast::Comment) -> Vec<Comment> {
         .filter(|s| !skippable(s))
         .map(|not| not.into_token().and_then(Comment::cast).filter(same_prefix))
         .take_while(|opt_com| opt_com.is_some())
-        .filter_map(identity);
+        .flatten();
 
     let mut comments: Vec<_> = prev_comments.collect();
     comments.reverse();

crates/ide_assists/src/handlers/expand_glob_import.rs

@@ -136,18 +136,13 @@ impl Refs {
                 .into_iter()
                 .filter(|r| {
                     if let Def::ModuleDef(ModuleDef::Trait(tr)) = r.def {
-                        if tr
-                            .items(ctx.db())
-                            .into_iter()
-                            .find(|ai| {
-                                if let AssocItem::Function(f) = *ai {
-                                    Def::ModuleDef(ModuleDef::Function(f)).is_referenced_in(ctx)
-                                } else {
-                                    false
-                                }
-                            })
-                            .is_some()
-                        {
+                        if tr.items(ctx.db()).into_iter().any(|ai| {
+                            if let AssocItem::Function(f) = ai {
+                                Def::ModuleDef(ModuleDef::Function(f)).is_referenced_in(ctx)
+                            } else {
+                                false
+                            }
+                        }) {
                             return true;
                         }
                     }

crates/ide_assists/src/handlers/reorder_impl.rs

@@ -95,7 +95,7 @@ fn compute_method_ranks(path: &ast::Path, ctx: &AssistContext) -> Option<FxHashM
                 _ => None,
             })
             .enumerate()
-            .map(|(idx, func)| ((func.name(ctx.db()).to_string(), idx)))
+            .map(|(idx, func)| (func.name(ctx.db()).to_string(), idx))
             .collect(),
     )
 }

crates/ide_completion/src/patterns.rs

@@ -71,7 +71,7 @@ fn test_has_block_expr_parent() {
 }
 
 pub(crate) fn has_bind_pat_parent(element: SyntaxElement) -> bool {
-    element.ancestors().find(|it| it.kind() == IDENT_PAT).is_some()
+    element.ancestors().any(|it| it.kind() == IDENT_PAT)
 }
 #[test]
 fn test_has_bind_pat_parent() {

crates/ide_ssr/src/parsing.rs

@@ -67,7 +67,7 @@ impl ParsedRule {
     ) -> Result<Vec<ParsedRule>, SsrError> {
         let raw_pattern = pattern.as_rust_code();
         let raw_template = template.map(|t| t.as_rust_code());
-        let raw_template = raw_template.as_ref().map(|s| s.as_str());
+        let raw_template = raw_template.as_deref();
         let mut builder = RuleBuilder {
             placeholders_by_stand_in: pattern.placeholders_by_stand_in(),
             rules: Vec::new(),

crates/mbe/src/tests/expand.rs

@@ -1225,8 +1225,7 @@ macro_rules! m {
     )
     .expand_statements(r#"m!(C("0"))"#)
     .descendants()
-    .find(|token| token.kind() == ERROR)
-    .is_some());
+    .any(|token| token.kind() == ERROR));
 }
 
 #[test]