From 054d071d8032e05f5235be754ccb8407480bb7ff Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micha=C5=82=20W=2E=20Urba=C5=84czyk?= <mwu-tow@gazeta.pl>
Date: Sat, 30 Oct 2021 14:45:49 +0200
Subject: [PATCH] bump toolchain, fix clear issues

---
 lib/rust/ast/src/generation.rs                | 14 ++++----
 lib/rust/ast/src/main.rs                      |  1 -
 lib/rust/automata/src/dfa.rs                  |  2 +-
 lib/rust/automata/src/nfa.rs                  | 10 +++---
 lib/rust/automata/src/pattern.rs              |  4 +--
 lib/rust/data/benches/bench_tree_query.rs     |  2 +-
 lib/rust/data/src/dependency_graph.rs         |  8 ++---
 lib/rust/flexer/src/generate.rs               |  2 +-
 lib/rust/flexer/src/group.rs                  |  2 +-
 .../tests/flexer_invalid_definitions.rs       |  2 ++
 lib/rust/lexer/definition/src/lexeme.rs       |  2 +-
 lib/rust/lexer/definition/src/token.rs        | 34 +++++++------------
 .../generation/benches/lexer_bench_sources.rs |  1 -
 lib/rust/lexer/generation/build.rs            |  4 +--
 lib/rust/lexer/generation/tests/test_utils.rs |  1 -
 lib/rust/macro-utils/src/lib.rs               |  2 +-
 lib/rust/optics/src/lib.rs                    |  2 +-
 lib/rust/prelude/src/data/non_empty_vec.rs    |  8 ++---
 lib/rust/prelude/src/lib.rs                   |  2 +-
 lib/rust/shapely/impl/tests/derivation.rs     |  2 +-
 .../shapely/impl/tests/derive_clone_ref.rs    | 12 +++----
 .../shapely/macros/src/derive_clone_ref.rs    |  4 +--
 .../shapely/macros/src/derive_iterator.rs     |  2 +-
 rust-toolchain                                |  1 +
 24 files changed, 55 insertions(+), 69 deletions(-)
 create mode 100644 rust-toolchain

diff --git a/lib/rust/ast/src/generation.rs b/lib/rust/ast/src/generation.rs
index d3ab6719c1..114aa5d124 100644
--- a/lib/rust/ast/src/generation.rs
+++ b/lib/rust/ast/src/generation.rs
@@ -50,18 +50,18 @@ impl ScalaGenerator {
     /// Generates a block of Scala code.
     fn block(&mut self, ident:&Ident, lines:&[syn::Item]) {
         write!(self.code, "\n{:i$}object " , "", i=self.indent);
-        self.typ_name(&ident);
+        self.typ_name(ident);
         writeln!(self.code, " {{");
         self.indent += 2;
-        if self.extends.contains_key(&ident) {
+        if self.extends.contains_key(ident) {
             write!(self.code, "{:i$}sealed trait ", "", i=self.indent);
-            self.typ_name(&ident);
-            self.extends(&ident);
+            self.typ_name(ident);
+            self.extends(ident);
         }
 
         for item in lines {
             match item {
-                syn::Item::Enum  (val) => self.adt(&val),
+                syn::Item::Enum  (val) => self.adt(val),
                 syn::Item::Type  (val) => {
                     write!(self.code, "\n{:i$}type ", "", i=self.indent);
                     self.typ_name(&val.ident);
@@ -101,7 +101,7 @@ impl ScalaGenerator {
         for (i, field) in fields.named.iter().enumerate()  {
             if i != 0 { write!(self.code, ", "); }
             if let Some(ident) = &field.ident {
-                self.var_name(&ident);
+                self.var_name(ident);
             }
             write!(self.code, ": ");
             self.typ(&field.ty);
@@ -170,7 +170,7 @@ impl ScalaGenerator {
     ///
     /// `foo` => `extends Foo`
     fn extends(&mut self, ident:&Ident) {
-        if let Some(name) = self.extends.get(&ident).cloned() {
+        if let Some(name) = self.extends.get(ident).cloned() {
             write!(self.code, " extends ");
             self.typ_name(&name);
         }
diff --git a/lib/rust/ast/src/main.rs b/lib/rust/ast/src/main.rs
index 7491242e71..84b48aed8e 100644
--- a/lib/rust/ast/src/main.rs
+++ b/lib/rust/ast/src/main.rs
@@ -1,6 +1,5 @@
 use ast::generation::ScalaGenerator;
 
-use clap;
 use std::fs::File;
 use std::io::Write;
 
diff --git a/lib/rust/automata/src/dfa.rs b/lib/rust/automata/src/dfa.rs
index 9f8e20c4eb..5da0b08788 100644
--- a/lib/rust/automata/src/dfa.rs
+++ b/lib/rust/automata/src/dfa.rs
@@ -66,7 +66,7 @@ impl Dfa {
 impl Dfa {
     /// Simulate the DFA transition with the provided input symbol.
     pub fn next_state(&self, current_state:State, symbol:&Symbol) -> State {
-        let ix = self.alphabet.index_of_symbol(&symbol);
+        let ix = self.alphabet.index_of_symbol(symbol);
         self.links.safe_index(current_state.id(),ix).unwrap_or_default()
     }
 
diff --git a/lib/rust/automata/src/nfa.rs b/lib/rust/automata/src/nfa.rs
index ce9b09149f..92907125c6 100644
--- a/lib/rust/automata/src/nfa.rs
+++ b/lib/rust/automata/src/nfa.rs
@@ -353,16 +353,16 @@ pub mod tests {
         }
 
         pub fn has_transition(&self, trigger:RangeInclusive<Symbol>, target:State) -> bool {
-            self.states.iter().any(|r| r.links().iter().find(|transition | {
+            self.states.iter().any(|r| r.links().iter().any(|transition | {
                     (transition.symbols == trigger) && transition.target == target
-                }).is_some())
+                }))
         }
 
         pub fn has_epsilon(&self, from:State, to:State) -> bool {
             self.states.iter().enumerate().fold(false,|l,(ix,r)| {
-                let state_has = ix == from.id() && r.epsilon_links().iter().find(|ident| {
-                    **ident == to
-                }).is_some();
+                let state_has = ix == from.id() && r.epsilon_links().iter().any(|ident| {
+                    *ident == to
+                });
                 l || state_has
             })
         }
diff --git a/lib/rust/automata/src/pattern.rs b/lib/rust/automata/src/pattern.rs
index 6e89d72e47..74d13cfab0 100644
--- a/lib/rust/automata/src/pattern.rs
+++ b/lib/rust/automata/src/pattern.rs
@@ -129,9 +129,7 @@ impl Pattern {
 
     /// This pattern doesn't trigger on any code contained in `codes`.
     pub fn none_of_codes(codes:&[u64],names:&[String]) -> Self {
-        if codes.len() != names.len() {
-            panic!("`codes` and `names`must have the same length.");
-        }
+        assert_eq!(codes.len(), names.len(), "`codes` and `names`must have the same length.");
         let mut codes = Vec::from(codes);
         codes.sort_unstable();
         codes.dedup();
diff --git a/lib/rust/data/benches/bench_tree_query.rs b/lib/rust/data/benches/bench_tree_query.rs
index 103c66df68..b42ae621d5 100644
--- a/lib/rust/data/benches/bench_tree_query.rs
+++ b/lib/rust/data/benches/bench_tree_query.rs
@@ -28,7 +28,7 @@ fn bench_config() -> Criterion {
 fn gen_tree(width:usize, depth:usize) -> HashMapTree<usize,usize> {
     let mut tree = HashMapTree::<usize,usize>::default();
     let paths    = (0..width).permutations(depth);
-    paths.into_iter().for_each(|p| tree.set(p.clone(),1));
+    paths.into_iter().for_each(|p| tree.set(p,1));
     tree
 }
 
diff --git a/lib/rust/data/src/dependency_graph.rs b/lib/rust/data/src/dependency_graph.rs
index 3f01424819..b40d33e4d3 100644
--- a/lib/rust/data/src/dependency_graph.rs
+++ b/lib/rust/data/src/dependency_graph.rs
@@ -102,7 +102,7 @@ impl<T:Clone+Eq+Hash+Ord> DependencyGraph<T> {
         let mut keys_iter    = keys.iter();
         let mut opt_key      = keys_iter.next();
         while let Some(key)  = opt_key {
-            match next_to_keep.as_ref().map(|t| t.cmp(&key)) {
+            match next_to_keep.as_ref().map(|t| t.cmp(key)) {
                 Some(std::cmp::Ordering::Less) => {
                     next_to_keep = keep.next()
                 },
@@ -111,13 +111,13 @@ impl<T:Clone+Eq+Hash+Ord> DependencyGraph<T> {
                     opt_key      = keys_iter.next();
                 }
                 _ => {
-                    if let Some(node) = self.nodes.get_mut(&key) {
+                    if let Some(node) = self.nodes.get_mut(key) {
                         let node = mem::take(node);
                         for key2 in node.ins {
-                            self.nodes.get_mut(&key2).for_each(|t| t.out.remove_item(&key))
+                            self.nodes.get_mut(&key2).for_each(|t| t.out.remove_item(key))
                         }
                         for key2 in node.out {
-                            self.nodes.get_mut(&key2).for_each(|t| t.ins.remove_item(&key))
+                            self.nodes.get_mut(&key2).for_each(|t| t.ins.remove_item(key))
                         }
                     }
                     opt_key = keys_iter.next();
diff --git a/lib/rust/flexer/src/generate.rs b/lib/rust/flexer/src/generate.rs
index 891396afd4..0df3061041 100644
--- a/lib/rust/flexer/src/generate.rs
+++ b/lib/rust/flexer/src/generate.rs
@@ -312,7 +312,7 @@ pub fn branch_body<S:BuildHasher>
         }
     } else {
         let target_state_has_no_rule = match rule_name_for_state {
-            Some(_) => if !dfa_has_rule_name_for(&data, dfa, target_state) {
+            Some(_) => if !dfa_has_rule_name_for(data, dfa, target_state) {
                 dfa.sources[target_state.id()] = (*sources).clone();
                 has_overlaps.insert(target_state.id(),true);
                 true
diff --git a/lib/rust/flexer/src/group.rs b/lib/rust/flexer/src/group.rs
index c0e0bcf306..d4b1a44709 100644
--- a/lib/rust/flexer/src/group.rs
+++ b/lib/rust/flexer/src/group.rs
@@ -192,7 +192,7 @@ impl AutomatonData {
 
     /// Get a reference to the states for this automaton.
     pub fn states(&self) -> &Vec<state::Data> {
-        &self.automaton.states()
+        self.automaton.states()
     }
 
     /// Get a reference to the state names for this automaton.
diff --git a/lib/rust/flexer/tests/flexer_invalid_definitions.rs b/lib/rust/flexer/tests/flexer_invalid_definitions.rs
index eb6b2c4721..4f261bae0c 100644
--- a/lib/rust/flexer/tests/flexer_invalid_definitions.rs
+++ b/lib/rust/flexer/tests/flexer_invalid_definitions.rs
@@ -4,6 +4,8 @@
 //! allows for increased clarity in the testing.
 
 #![allow(missing_docs)]
+#![allow(clippy::blacklisted_name)] // `foo` is fine here.
+#![allow(clippy::new_without_default)] // No need for boilerplate in throwaway test code.
 
 use enso_flexer::*;
 
diff --git a/lib/rust/lexer/definition/src/lexeme.rs b/lib/rust/lexer/definition/src/lexeme.rs
index 853ce8865b..0ee43fd59c 100644
--- a/lib/rust/lexer/definition/src/lexeme.rs
+++ b/lib/rust/lexer/definition/src/lexeme.rs
@@ -282,7 +282,7 @@ pub mod literal {
 
 /// Get the first character of the lexeme, if it exists.
 pub fn char(literal:&'static str) -> Option<char> {
-    literal.chars().nth(0)
+    literal.chars().next()
 }
 
 /// Get the first character of the lexeme, assuming that it exists.
diff --git a/lib/rust/lexer/definition/src/token.rs b/lib/rust/lexer/definition/src/token.rs
index 7e31940be5..ff6d3c2d7d 100644
--- a/lib/rust/lexer/definition/src/token.rs
+++ b/lib/rust/lexer/definition/src/token.rs
@@ -390,30 +390,17 @@ impl TextStyle {
 
     /// Check if the text literal is a line literal.
     pub fn is_line_literal(self) -> bool {
-        match self {
-            TextStyle::RawLine      => true,
-            TextStyle::FormatLine   => true,
-            TextStyle::UnclosedLine => true,
-            _                       => false,
-        }
+        matches!(self, TextStyle::RawLine | TextStyle::FormatLine | TextStyle::UnclosedLine)
     }
 
     /// Check if the text literal is an inline block literal.
     pub fn is_inline_block_literal(self) -> bool {
-        match self {
-            TextStyle::FormatInlineBlock => true,
-            TextStyle::RawInlineBlock    => true,
-            _                            => false,
-        }
+        matches!(self, TextStyle::FormatInlineBlock | TextStyle::RawInlineBlock)
     }
 
     /// Check if the text literal is a block literal.
     pub fn is_block_literal(self) -> bool {
-        match self {
-            TextStyle::FormatBlock => true,
-            TextStyle::RawBlock    => true,
-            _                      => false,
-        }
+        matches!(self, TextStyle::FormatBlock | TextStyle::RawBlock)
     }
 }
 
@@ -761,9 +748,14 @@ impl Stream {
     pub fn tokens_len(&self) -> usize {
         self.tokens.iter().map(|token|token.length + token.offset).sum()
     }
+}
 
-    /// Get a consuming iterator over the token stream.
-    pub fn into_iter(self) -> std::vec::IntoIter<Token> {
+/// Get a consuming iterator over the token stream.
+impl std::iter::IntoIterator for Stream {
+    type Item = Token;
+    type IntoIter = std::vec::IntoIter<Self::Item>;
+
+    fn into_iter(self) -> Self::IntoIter {
         self.tokens.into_iter()
     }
 }
@@ -791,8 +783,8 @@ impl From<Vec<Token>> for Stream {
     }
 }
 
-impl Into<Vec<Token>> for Stream {
-    fn into(self) -> Vec<Token> {
-        self.tokens
+impl From<Stream> for Vec<Token> {
+    fn from(stream: Stream) -> Self {
+        stream.tokens
     }
 }
diff --git a/lib/rust/lexer/generation/benches/lexer_bench_sources.rs b/lib/rust/lexer/generation/benches/lexer_bench_sources.rs
index 1b5548a06a..c827df99fe 100644
--- a/lib/rust/lexer/generation/benches/lexer_bench_sources.rs
+++ b/lib/rust/lexer/generation/benches/lexer_bench_sources.rs
@@ -2,7 +2,6 @@
 //! benchmarking the Enso lexer.
 
 use criterion::{black_box, Criterion, Throughput};
-use lexer;
 use std::time::Duration;
 
 
diff --git a/lib/rust/lexer/generation/build.rs b/lib/rust/lexer/generation/build.rs
index aea553c69d..6016f5c660 100644
--- a/lib/rust/lexer/generation/build.rs
+++ b/lib/rust/lexer/generation/build.rs
@@ -16,9 +16,9 @@ fn generate_engine() -> std::io::Result<()> {
     let output_path      = "src/generated/engine.rs";
     let definition_error = format!("The lexer definition should exist at {}.",definition_path);
     let output_error     = format!("Cannot open output file at {}.",output_path);
-    let mut lexer_def    = File::open(definition_path).expect(definition_error.as_str());
+    let mut lexer_def    = File::open(definition_path).expect(&definition_error);
     let mut contents     = String::new();
-    let mut file         = File::create(output_path).expect(output_error.as_str());
+    let mut file         = File::create(output_path).expect(&output_error);
     let lexer            = EnsoLexer::define();
     let engine           = lexer.specialize().unwrap();
     lexer_def.read_to_string(&mut contents).expect("Unable to read lexer definition.");
diff --git a/lib/rust/lexer/generation/tests/test_utils.rs b/lib/rust/lexer/generation/tests/test_utils.rs
index 19da65c949..51d1d3bb85 100644
--- a/lib/rust/lexer/generation/tests/test_utils.rs
+++ b/lib/rust/lexer/generation/tests/test_utils.rs
@@ -5,7 +5,6 @@
 use enso_flexer::*;
 use lexer_definition::library::*;
 
-use lexer;
 use lexer_definition::library::token::Token;
 
 
diff --git a/lib/rust/macro-utils/src/lib.rs b/lib/rust/macro-utils/src/lib.rs
index 7e8c3a8d5c..3ade666ed6 100644
--- a/lib/rust/macro-utils/src/lib.rs
+++ b/lib/rust/macro-utils/src/lib.rs
@@ -213,7 +213,7 @@ pub fn gather_all_types(node:&syn::Type) -> Vec<&syn::TypePath> {
 
 /// All text representations of `TypePath`s in the given's `Type` subtree.
 pub fn gather_all_type_reprs(node:&syn::Type) -> Vec<String> {
-    gather_all_types(node).iter().map(|t| repr(t)).collect()
+    gather_all_types(node).iter().map(repr).collect()
 }
 
 
diff --git a/lib/rust/optics/src/lib.rs b/lib/rust/optics/src/lib.rs
index 490c7273a6..0bb2d83979 100644
--- a/lib/rust/optics/src/lib.rs
+++ b/lib/rust/optics/src/lib.rs
@@ -165,7 +165,7 @@ impl<Src,Tgt,Path> OptLens<Src,Tgt,Path> {
 impl<Src,Tgt,Path> Lens<Src,Tgt,Path> {
     pub fn resolve(self, t: &Src) -> &NestedField<Src, Path>
     where Path: Resolver<Src> {
-        <Path as Resolver<Src>>::resolve(&t)
+        <Path as Resolver<Src>>::resolve(t)
     }
 }
 
diff --git a/lib/rust/prelude/src/data/non_empty_vec.rs b/lib/rust/prelude/src/data/non_empty_vec.rs
index fa51ae4c32..6cf2259158 100644
--- a/lib/rust/prelude/src/data/non_empty_vec.rs
+++ b/lib/rust/prelude/src/data/non_empty_vec.rs
@@ -89,9 +89,7 @@ impl<T> NonEmptyVec<T> {
     /// vec.push(11);
     /// ```
     pub fn with_capacity(first:T, capacity:usize) -> NonEmptyVec<T> {
-        if capacity == 0 {
-            panic!("Capacity must be greater than zero for a NonEmptyVec.");
-        }
+        assert_ne!(capacity, 0, "Capacity must be greater than zero for a NonEmptyVec.");
         let mut elems = Vec::with_capacity(capacity);
         elems.push(first);
         NonEmptyVec{elems}
@@ -198,7 +196,7 @@ impl<T> NonEmptyVec<T> {
     /// assert_eq!(*vec.first(), 0);
     /// ```
     pub fn first(&self) -> &T {
-        &self.elems.first().expect("The NonEmptyVec always has an item in it.")
+        self.elems.first().expect("The NonEmptyVec always has an item in it.")
     }
 
     /// Obtain a mutable reference to the head of the `NonEmptyVec`.
@@ -309,4 +307,4 @@ impl<T:Default> Default for NonEmptyVec<T> {
     fn default() -> Self {
         Self::singleton(default())
     }
-}
\ No newline at end of file
+}
diff --git a/lib/rust/prelude/src/lib.rs b/lib/rust/prelude/src/lib.rs
index 8ae01b0911..ae6a2cd40b 100644
--- a/lib/rust/prelude/src/lib.rs
+++ b/lib/rust/prelude/src/lib.rs
@@ -394,7 +394,7 @@ pub trait WeakRef : CloneRef {
 impl<T:?Sized> StrongRef for Rc<T> {
     type WeakRef = Weak<T>;
     fn downgrade(&self) -> Self::WeakRef {
-        Rc::downgrade(&self)
+        Rc::downgrade(self)
     }
 }
 
diff --git a/lib/rust/shapely/impl/tests/derivation.rs b/lib/rust/shapely/impl/tests/derivation.rs
index c65f75c04d..ba976617bf 100644
--- a/lib/rust/shapely/impl/tests/derivation.rs
+++ b/lib/rust/shapely/impl/tests/derivation.rs
@@ -1,5 +1,5 @@
 #![feature(generators)]
-#![feature(min_type_alias_impl_trait)]
+#![feature(type_alias_impl_trait)]
 
 use enso_shapely::*;
 
diff --git a/lib/rust/shapely/impl/tests/derive_clone_ref.rs b/lib/rust/shapely/impl/tests/derive_clone_ref.rs
index e1e1972947..8783c0c70d 100644
--- a/lib/rust/shapely/impl/tests/derive_clone_ref.rs
+++ b/lib/rust/shapely/impl/tests/derive_clone_ref.rs
@@ -16,11 +16,11 @@ use enso_prelude::*;
 #[derive(Clone,CloneRef)] enum EnumEmpty {}
 
 #[derive(Clone,CloneRef)] enum Enum {
-    VariantUnit,
-    VariantNamedEmpty {},
-    VariantNamed {named0:Rc<i32>,named1:Rc<String>},
-    VariantUnnamedEmpty(),
-    VariantUnnamed(Rc<i32>,Rc<String>),
+    Unit,
+    NamedEmpty {},
+    Named {named0:Rc<i32>,named1:Rc<String>},
+    UnnamedEmpty(),
+    Unnamed(Rc<i32>,Rc<String>),
 }
 
 #[derive(CloneRef,Derivative)]
@@ -42,7 +42,7 @@ struct StructBoundGeneric<T:Display>(Rc<T>);
 #[derive(CloneRef,Derivative)]
 #[derivative(Clone(bound=""))]
 // Note: CloneRef "knows" about `Display` bound.
-struct StructGenericLifetime<'t>(Rc<&'t String>);
+struct StructGenericLifetime<'t>(PhantomData<&'t String>);
 
 #[derive(CloneRef,Derivative)]
 #[derivative(Clone(bound=""))]
diff --git a/lib/rust/shapely/macros/src/derive_clone_ref.rs b/lib/rust/shapely/macros/src/derive_clone_ref.rs
index eb40183ee5..28f4fde35d 100644
--- a/lib/rust/shapely/macros/src/derive_clone_ref.rs
+++ b/lib/rust/shapely/macros/src/derive_clone_ref.rs
@@ -147,9 +147,7 @@ pub fn clone_ref_bounds(attr:&Attribute) -> Option<Vec<WherePredicate>> {
         Meta::List(ml) => ml.nested,
         _              => panic!("Attribute contents does not conform to meta item."),
     };
-    if list.len() > 1 {
-        panic!("Only a single entry within `{}` attribute is allowed.",CLONE_REF_ATTR);
-    }
+    assert!(list.len() <= 1,"Only a single entry within `{}` attribute is allowed.",CLONE_REF_ATTR);
     let bound_value = match list.first() {
         Some(NestedMeta::Meta(Meta::NameValue(name_val))) => {
             if is_custom_bound(name_val) {
diff --git a/lib/rust/shapely/macros/src/derive_iterator.rs b/lib/rust/shapely/macros/src/derive_iterator.rs
index 360d3fc1f5..5b6fb6ba5b 100644
--- a/lib/rust/shapely/macros/src/derive_iterator.rs
+++ b/lib/rust/shapely/macros/src/derive_iterator.rs
@@ -91,7 +91,7 @@ impl<'t> DependentValue<'t> {
         match self.ty {
             syn::Type::Tuple(tuple) => self.yield_tuple_value(tuple, is_mut),
             syn::Type::Path(path)   => {
-                if type_matches(&self.ty, &self.target_param) {
+                if type_matches(self.ty, self.target_param) {
                     self.yield_direct_value(is_mut)
                 } else {
                     self.yield_dependent_ty_path_value(path,is_mut)
diff --git a/rust-toolchain b/rust-toolchain
new file mode 100644
index 0000000000..986feef291
--- /dev/null
+++ b/rust-toolchain
@@ -0,0 +1 @@
+nightly-2021-10-29