Rest of clippy lints

schala-lang/codegen/src/lib.rs

@@ -15,7 +15,7 @@ struct RecursiveDescentFn {
 impl Fold for RecursiveDescentFn {
   fn fold_item_fn(&mut self, mut i: syn::ItemFn) -> syn::ItemFn {
     let box block = i.block;
-    let ref ident = i.ident;
+    let ident = &i.ident;
 
     let new_block: syn::Block = parse_quote! {
       {

schala-lang/language/src/ast/mod.rs

@@ -1,5 +1,7 @@
-use std::rc::Rc;
+#![allow(clippy::upper_case_acronyms)]
+#![allow(clippy::enum_variant_names)]
 
+use std::rc::Rc;
 use crate::derivative::Derivative;
 
 mod walker;

schala-lang/language/src/ast/visitor.rs

@@ -6,26 +6,28 @@ use crate::ast::*;
 
 pub trait ASTVisitor: Sized {
   fn ast(&mut self, _ast: &AST) {}
-  fn block(&mut self, _statements: &Vec<Statement>) {}
+  fn block(&mut self, _statements: &[ Statement ]) {}
   fn statement(&mut self, _statement: &Statement) {}
   fn declaration(&mut self, _declaration: &Declaration) {}
   fn signature(&mut self, _signature: &Signature) {}
   fn type_declaration(&mut self, _name: &TypeSingletonName, _body: &TypeBody, _mutable: bool) {}
   fn type_alias(&mut self, _alias: &Rc<String>, _original: &Rc<String>) {}
   fn binding(&mut self, _name: &Rc<String>, _constant: bool, _type_anno: Option<&TypeIdentifier>, _expr: &Expression) {}
-  fn implemention(&mut self, _type_name: &TypeIdentifier, _interface_name: Option<&TypeSingletonName>, _block: &Vec<Declaration>) {}
-  fn interface(&mut self, _name: &Rc<String>, _signatures: &Vec<Signature>) {}
+  fn implemention(&mut self, _type_name: &TypeIdentifier, _interface_name: Option<&TypeSingletonName>, _block: &[ Declaration ]) {}
+  fn interface(&mut self, _name: &Rc<String>, _signatures: &[ Signature ]) {}
   fn expression(&mut self, _expression: &Expression) {}
   fn expression_kind(&mut self, _kind: &ExpressionKind) {}
   fn type_annotation(&mut self, _type_anno: Option<&TypeIdentifier>) {}
-  fn named_struct(&mut self, _name: &QualifiedName, _fields: &Vec<(Rc<String>, Expression)>) {}
-  fn call(&mut self, _f: &Expression, _arguments: &Vec<InvocationArgument>) {}
-  fn index(&mut self, _indexee: &Expression, _indexers: &Vec<Expression>) {}
+  fn named_struct(&mut self, _name: &QualifiedName, _fields: &[ (Rc<String>, Expression) ]) {}
+  fn call(&mut self, _f: &Expression, _arguments: &[ InvocationArgument ]) {}
+  fn index(&mut self, _indexee: &Expression, _indexers: &[ Expression ]) {}
   fn if_expression(&mut self, _discrim: Option<&Expression>, _body: &IfExpressionBody) {}
   fn condition_arm(&mut self, _arm: &ConditionArm) {}
+  #[allow(clippy::ptr_arg)]
   fn while_expression(&mut self, _condition: Option<&Expression>, _body: &Block) {}
-  fn for_expression(&mut self, _enumerators: &Vec<Enumerator>, _body: &ForBody) {}
-  fn lambda(&mut self, _params: &Vec<FormalParam>, _type_anno: Option<&TypeIdentifier>, _body: &Block) {}
+  fn for_expression(&mut self, _enumerators: &[ Enumerator ], _body: &ForBody) {}
+  #[allow(clippy::ptr_arg)]
+  fn lambda(&mut self, _params: &[ FormalParam ], _type_anno: Option<&TypeIdentifier>, _body: &Block) {}
   fn invocation_argument(&mut self, _arg: &InvocationArgument) {}
   fn formal_param(&mut self, _param: &FormalParam) {}
   fn import(&mut self, _import: &ImportSpecifier) {}

schala-lang/language/src/ast/walker.rs

@@ -9,6 +9,7 @@ pub fn walk_ast<V: ASTVisitor>(v: &mut V, ast: &AST) {
   walk_block(v, &ast.statements);
 }
 
+#[allow(clippy::ptr_arg)]
 fn walk_block<V: ASTVisitor>(v: &mut V, block: &Vec<Statement>) {
   for s in block {
     v.statement(s);
@@ -39,12 +40,12 @@ fn declaration<V: ASTVisitor>(v: &mut V, decl: &Declaration) {
   use Declaration::*;
   match decl {
     FuncSig(sig) => {
-      v.signature(&sig);
-      signature(v, &sig);
+      v.signature(sig);
+      signature(v, sig);
     },
     FuncDecl(sig, block) => {
-      v.signature(&sig);
-      v.block(&block);
+      v.signature(sig);
+      v.block(block);
       walk_block(v, block);
     },
     TypeDecl { name, body, mutable  } => v.type_declaration(name, body, *mutable),
@@ -52,8 +53,8 @@ fn declaration<V: ASTVisitor>(v: &mut V, decl: &Declaration) {
     Binding { name, constant, type_anno, expr } => {
       v.binding(name, *constant, type_anno.as_ref(), expr);
       v.type_annotation(type_anno.as_ref());
-      v.expression(&expr);
-      expression(v, &expr);
+      v.expression(expr);
+      expression(v, expr);
     },
     Impl { type_name, interface_name, block } => {
       v.implemention(type_name, interface_name.as_ref(), block);
@@ -79,7 +80,7 @@ fn expression<V: ASTVisitor>(v: &mut V, expression: &Expression) {
 }
 
 
-fn call<V: ASTVisitor>(v: &mut V, f: &Expression, args: &Vec<InvocationArgument>) {
+fn call<V: ASTVisitor>(v: &mut V, f: &Expression, args: &[ InvocationArgument ]) {
   v.expression(f);
   expression(v, f);
   for arg in args.iter() {
@@ -103,20 +104,21 @@ fn invocation_argument<V: ASTVisitor>(v: &mut V, arg: &InvocationArgument) {
   }
 }
 
-fn index<V: ASTVisitor>(v: &mut V, indexee: &Expression, indexers: &Vec<Expression>) {
+fn index<V: ASTVisitor>(v: &mut V, indexee: &Expression, indexers: &[ Expression ]) {
   v.expression(indexee);
   for i in indexers.iter() {
     v.expression(i);
   }
 }
 
-fn named_struct<V: ASTVisitor>(v: &mut V, n: &QualifiedName, fields: &Vec<(Rc<String>, Expression)>) {
+fn named_struct<V: ASTVisitor>(v: &mut V, n: &QualifiedName, fields: &[ (Rc<String>, Expression) ]) {
   v.qualified_name(n);
   for (_, expr) in fields.iter() {
     v.expression(expr);
   }
 }
 
+#[allow(clippy::ptr_arg)]
 fn lambda<V: ASTVisitor>(v: &mut V, params: &Vec<FormalParam>, type_anno: Option<&TypeIdentifier>, body: &Block) {
   for param in params {
     v.formal_param(param);
@@ -128,11 +130,11 @@ fn lambda<V: ASTVisitor>(v: &mut V, params: &Vec<FormalParam>, type_anno: Option
 }
 
 fn formal_param<V: ASTVisitor>(v: &mut V, param: &FormalParam) {
-  param.default.as_ref().map(|p| {
-    v.expression(p);
-    expression(v, p);
-  });
-  v.type_annotation(param.anno.as_ref());
+    if let Some(p) = param.default.as_ref() {
+        v.expression(p);
+        expression(v, p);
+    };
+    v.type_annotation(param.anno.as_ref());
 }
 
 fn expression_kind<V: ASTVisitor>(v: &mut V, expression_kind: &ExpressionKind) {
@@ -172,7 +174,7 @@ fn expression_kind<V: ASTVisitor>(v: &mut V, expression_kind: &ExpressionKind) {
     },
     IfExpression { discriminator, body } => {
       v.if_expression(deref_optional_box(discriminator), body);
-      discriminator.as_ref().map(|d| expression(v, d));
+      if let Some(d) = discriminator.as_ref() { expression(v, d) }
       if_expression_body(v, body);
     },
     WhileExpression { condition, body } => v.while_expression(deref_optional_box(condition), body),
@@ -195,13 +197,13 @@ fn if_expression_body<V: ASTVisitor>(v: &mut V, body: &IfExpressionBody) {
   match body {
     SimpleConditional { then_case, else_case } => {
       walk_block(v, then_case);
-      else_case.as_ref().map(|block| walk_block(v, block));
+      if let Some(block) = else_case.as_ref() { walk_block(v, block) }
     },
     SimplePatternMatch { pattern, then_case, else_case } => {
       v.pattern(pattern);
       walk_pattern(v, pattern);
       walk_block(v, then_case);
-      else_case.as_ref().map(|block| walk_block(v, block));
+      if let Some(block) = else_case.as_ref() { walk_block(v, block) }
     },
     CondList(arms) => {
       for arm in arms {
@@ -230,10 +232,10 @@ fn condition_arm<V: ASTVisitor>(v: &mut V, arm: &ConditionArm) {
     },
     _ => ()
   }
-  arm.guard.as_ref().map(|guard| {
-    v.expression(guard);
-    expression(v, guard);
-  });
+  if let Some(guard) = arm.guard.as_ref() {
+      v.expression(guard);
+      expression(v, guard);
+  };
   v.block(&arm.body);
   walk_block(v, &arm.body);
 }

schala-lang/language/src/eval/test.rs

@@ -13,15 +13,15 @@ fn evaluate_all_outputs(input: &str) -> Vec<Result<String, String>> {
   let reduced = reduce(&ast, &symbol_table);
 
   let mut state = State::new();
-  let all_output = state.evaluate(reduced, true);
-  all_output
+  
+  state.evaluate(reduced, true)
 }
 
 macro_rules! test_in_fresh_env {
   ($string:expr, $correct:expr) => {
     {
       let all_output = evaluate_all_outputs($string);
-      let ref output = all_output.last().unwrap();
+      let output = &all_output.last().unwrap();
       assert_eq!(**output, Ok($correct.to_string()));
     }
   }

schala-lang/language/src/parsing/mod.rs

@@ -1,3 +1,5 @@
+#![allow(clippy::upper_case_acronyms)]
+
 //! # Parsing
 //! This module is where the recursive-descent parsing methods live.
 //!
@@ -230,15 +232,15 @@ impl TokenHandler {
     self.peek_n(n).kind
   }
   fn peek(&mut self) -> Token {
-    self.tokens.get(self.idx).map(|t: &Token| { t.clone()}).unwrap_or(Token { kind: TokenKind::EOF, location: self.end_of_file })
+    self.tokens.get(self.idx).cloned().unwrap_or(Token { kind: TokenKind::EOF, location: self.end_of_file })
   }
   /// calling peek_n(0) is the same thing as peek()
   fn peek_n(&mut self, n: usize) -> Token {
-    self.tokens.get(self.idx + n).map(|t: &Token| { t.clone()}).unwrap_or(Token { kind: TokenKind::EOF, location: self.end_of_file })
+    self.tokens.get(self.idx + n).cloned().unwrap_or(Token { kind: TokenKind::EOF, location: self.end_of_file })
   }
   fn next(&mut self) -> Token {
     self.idx += 1;
-    self.tokens.get(self.idx - 1).map(|t: &Token| { t.clone() }).unwrap_or(Token { kind: TokenKind::EOF, location: self.end_of_file })
+    self.tokens.get(self.idx - 1).cloned().unwrap_or(Token { kind: TokenKind::EOF, location: self.end_of_file })
   }
 }
 
@@ -371,11 +373,11 @@ impl Parser {
     let kind = match tok.get_kind() {
       Keyword(Type) => self.type_declaration().map(|decl| { StatementKind::Declaration(decl) }),
       Keyword(Func)=> self.func_declaration().map(|func| { StatementKind::Declaration(func) }),
-      Keyword(Let) => self.binding_declaration().map(|decl| StatementKind::Declaration(decl)),
-      Keyword(Interface) => self.interface_declaration().map(|decl| StatementKind::Declaration(decl)),
-      Keyword(Impl) => self.impl_declaration().map(|decl| StatementKind::Declaration(decl)),
-      Keyword(Import) => self.import_declaration().map(|spec| StatementKind::Import(spec)),
-      Keyword(Module) => self.module_declaration().map(|spec| StatementKind::Module(spec)),
+      Keyword(Let) => self.binding_declaration().map(StatementKind::Declaration),
+      Keyword(Interface) => self.interface_declaration().map(StatementKind::Declaration),
+      Keyword(Impl) => self.impl_declaration().map(StatementKind::Declaration),
+      Keyword(Import) => self.import_declaration().map(StatementKind::Import),
+      Keyword(Module) => self.module_declaration().map(StatementKind::Module),
       _ => self.expression().map(|expr| { StatementKind::Expression(expr) } ),
     }?;
     let id = self.id_store.fresh();
@@ -417,15 +419,10 @@ impl Parser {
 
   #[recursive_descent_method]
   fn type_body(&mut self) -> ParseResult<TypeBody> {
-    let mut variants = Vec::new();
-    variants.push(self.variant_specifier()?);
-    loop {
-      if let Pipe = self.token_handler.peek_kind() {
+    let mut variants = vec![self.variant_specifier()?];
+    while let Pipe = self.token_handler.peek_kind() {
         self.token_handler.next();
         variants.push(self.variant_specifier()?);
-      } else {
-        break;
-      }
     }
     Ok(TypeBody(variants))
   }
@@ -472,7 +469,7 @@ impl Parser {
     expect!(self, Keyword(Func));
     let (name, operator) = match self.token_handler.peek_kind() {
       Operator(s) => {
-        let name = s.clone();
+        let name = s;
         self.token_handler.next();
         (name, true)
       },
@@ -582,7 +579,7 @@ impl Parser {
       Colon => Some(self.type_anno()?),
       _ => None
     };
-    if let Some(_) = expr_body.type_anno {
+    if expr_body.type_anno.is_some() {
       return ParseError::new_with_token("Bad parse state encountered", self.token_handler.peek());
     }
     expr_body.type_anno = type_anno;
@@ -616,10 +613,11 @@ impl Parser {
   }
 
   // this implements Pratt parsing, see http://journal.stuffwithstuff.com/2011/03/19/pratt-parsers-expression-parsing-made-easy/
+  #[allow(clippy::while_let_loop)]
   fn precedence_expr(&mut self, precedence: i32) -> ParseResult<Expression> {
     let record = ParseRecord {
       production_name: "precedence_expr".to_string(),
-      next_token: format!("{}", self.token_handler.peek().to_string_with_metadata()),
+      next_token: self.token_handler.peek().to_string_with_metadata(),
       level: self.parse_level,
     };
     self.parse_level += 1;
@@ -691,7 +689,7 @@ impl Parser {
             self.token_handler.next();
             self.token_handler.next();
             let expr = self.expression()?;
-            InvocationArgument::Keyword { name: s.clone(), expr }
+            InvocationArgument::Keyword { name: s, expr }
           },
           _ => {
             let expr = self.expression()?;
@@ -799,14 +797,11 @@ impl Parser {
   #[recursive_descent_method]
   fn qualified_identifier(&mut self) -> ParseResult<Vec<Rc<String>>> {
     let mut components = vec![self.identifier()?];
-    loop {
-      match (self.token_handler.peek_kind(), self.token_handler.peek_kind_n(1)) {
-        (Colon, Colon) => {
-          self.token_handler.next(); self.token_handler.next();
-          components.push(self.identifier()?);
-        },
-        _ => break,
-      }
+
+    while let (Colon, Colon) = (self.token_handler.peek_kind(), self.token_handler.peek_kind_n(1)) {
+        self.token_handler.next();
+        self.token_handler.next();
+        components.push(self.identifier()?);
     }
     Ok(components)
   }
@@ -1023,7 +1018,7 @@ impl Parser {
         let pat = self.pattern()?;
         (name, pat)
       },
-      _ => (name.clone(), Pattern::Literal(PatternLiteral::StringPattern(name.clone())))
+      _ => (name.clone(), Pattern::Literal(PatternLiteral::StringPattern(name)))
     })
   }
 
@@ -1054,7 +1049,7 @@ impl Parser {
       self.restrictions.no_struct_literal = true;
       let x = self.while_cond();
       self.restrictions.no_struct_literal = false;
-      x?.map(|expr| Box::new(expr))
+      x?.map(Box::new)
     };
     let body = self.block()?;
     Ok(Expression::new(self.id_store.fresh(), WhileExpression {condition, body}))
@@ -1140,7 +1135,7 @@ impl Parser {
       StrLiteral {s, ..} => {
         self.token_handler.next();
         let id = self.id_store.fresh();
-        Ok(Expression::new(id, StringLiteral(s.clone())))
+        Ok(Expression::new(id, StringLiteral(s)))
       }
       e => ParseError::new_with_token(format!("Expected a literal expression, got {:?}", e), tok),
     }
@@ -1180,7 +1175,7 @@ impl Parser {
     let mut digits = self.digits()?;
     if let Period = self.token_handler.peek_kind() {
       self.token_handler.next();
-      digits.push_str(".");
+      digits.push('.');
       digits.push_str(&self.digits()?);
       match digits.parse::<f64>() {
         Ok(f) => Ok(Expression::new(self.id_store.fresh(), FloatLiteral(f))),
@@ -1211,20 +1206,16 @@ impl Parser {
   #[recursive_descent_method]
   fn import_declaration(&mut self) -> ParseResult<ImportSpecifier> {
     expect!(self, Keyword(Import));
-    let mut path_components = vec![];
-    path_components.push(self.identifier()?);
-    loop {
-      match (self.token_handler.peek_kind(), self.token_handler.peek_kind_n(1)) {
-        (Colon, Colon) => {
-          self.token_handler.next(); self.token_handler.next();
-          if let Identifier(_) = self.token_handler.peek_kind() {
+    let mut path_components = vec![self.identifier()?];
+
+    while let (Colon, Colon) = (self.token_handler.peek_kind(), self.token_handler.peek_kind_n(1)) {
+        self.token_handler.next();
+        self.token_handler.next();
+        if let Identifier(_) = self.token_handler.peek_kind() {
             path_components.push(self.identifier()?);
-          } else {
+        } else {
             break;
-          }
-        },
-        _ => break,
-      }
+        }
     }
 
     let imported_names = match self.token_handler.peek_kind() {

schala-lang/language/src/parsing/test.rs

@@ -1,4 +1,7 @@
 #![cfg(test)]
+#![allow(clippy::upper_case_acronyms)]
+#![allow(clippy::vec_init_then_push)]
+
 use std::rc::Rc;
 
 use crate::tokenizing::Location;
@@ -170,12 +173,12 @@ fn parsing_tuples() {
   parse_test_wrap_ast!("()", exst!(TupleLiteral(vec![])));
   parse_test_wrap_ast!("(\"hella\", 34)", exst!(
     TupleLiteral(
-      vec![ex!(s r#""hella""#).into(), ex!(s "34").into()]
+      vec![ex!(s r#""hella""#), ex!(s "34")]
     )
   ));
   parse_test_wrap_ast!("((1+2), \"slough\")", exst!(TupleLiteral(vec![
-    ex!(binexp!("+", NatLiteral(1), NatLiteral(2))).into(),
-    ex!(StringLiteral(rc!(slough))).into(),
+    ex!(binexp!("+", NatLiteral(1), NatLiteral(2))),
+    ex!(StringLiteral(rc!(slough))),
   ])))
 }
 
@@ -255,7 +258,7 @@ fn parsing_functions() {
   parse_test_wrap_ast!("oi()", exst!(Call { f: bx!(ex!(val!("oi"))), arguments: vec![] }));
   parse_test_wrap_ast!("oi(a, 2 + 2)", exst!(Call
   { f: bx!(ex!(val!("oi"))),
-    arguments: vec![inv!(ex!(val!("a"))), inv!(ex!(binexp!("+", NatLiteral(2), NatLiteral(2)))).into()]
+    arguments: vec![inv!(ex!(val!("a"))), inv!(ex!(binexp!("+", NatLiteral(2), NatLiteral(2))))]
   }));
   parse_error!("a(b,,c)");
 
@@ -541,7 +544,7 @@ fn parsing_lambdas() {
         type_anno: None,
         body: vec![exst!(s "y")] }
       )),
-      arguments: vec![inv!(ex!(NatLiteral(1))).into()] })
+      arguments: vec![inv!(ex!(NatLiteral(1)))] })
   };
 
   parse_test_wrap_ast! {
@@ -589,7 +592,7 @@ fn more_advanced_lambdas() {
         exst! {
         Call {
           f: bx!(ex!(Call { f: bx!(ex!(val!("wahoo"))), arguments: vec![] })),
-          arguments: vec![inv!(ex!(NatLiteral(3))).into()],
+          arguments: vec![inv!(ex!(NatLiteral(3)))],
         }
       }
     ]

schala-lang/language/src/symbol_table/resolver.rs

@@ -92,7 +92,7 @@ impl<'a> ASTVisitor for Resolver<'a> {
     self.symbol_table.id_to_fqsn.insert(qualified_name.id.clone(), fqsn);
   }
 
-  fn named_struct(&mut self, qualified_name: &QualifiedName, _fields: &Vec<(Rc<String>, Expression)>) {
+  fn named_struct(&mut self, qualified_name: &QualifiedName, _fields: &[ (Rc<String>, Expression) ]) {
     let fqsn = self.lookup_name_in_scope(qualified_name);
     self.symbol_table.id_to_fqsn.insert(qualified_name.id.clone(), fqsn);
   }

schala-lang/language/src/tokenizing.rs

@@ -1,8 +1,9 @@
+#![allow(clippy::upper_case_acronyms)]
+
 use itertools::Itertools;
 use std::{iter::{Iterator, Peekable}, convert::TryFrom, rc::Rc, fmt};
 use std::convert::TryInto;
 
-
 /// A location in a particular source file. Note that the
 /// sizes of the internal unsigned integer types limit
 /// the size of a source file to 2^32 lines of

schala-lang/language/src/typechecking.rs

@@ -1,5 +1,4 @@
 use std::rc::Rc;
-use std::fmt::Write;
 use std::convert::TryFrom;
 
 use ena::unify::{UnifyKey, InPlaceUnificationTable, UnificationTable, EqUnifyValue};
@@ -79,19 +78,21 @@ pub enum TypeConst {
 }
 
 impl TypeConst {
+    /*
   #[allow(dead_code)]
   pub fn to_string(&self) -> String {
     use self::TypeConst::*;
     match self {
-      Unit => format!("()"),
-      Nat => format!("Nat"),
-      Int => format!("Int"),
-      Float => format!("Float"),
-      StringT => format!("String"),
-      Bool => format!("Bool"),
-      Ordering => format!("Ordering"),
+      Unit => "()".to_string(),
+      Nat => "Nat".to_string(),
+      Int => "Int".to_string(),
+      Float => "Float".to_string(),
+      StringT => "String".to_string(),
+      Bool => "Bool".to_string(),
+      Ordering => "Ordering".to_string(),
     }
   }
+    */
 }
 
 impl EqUnifyValue for TypeConst { }
@@ -110,6 +111,7 @@ macro_rules! ty {
 
 //TODO find a better way to capture the to/from string logic
 impl Type {
+    /*
   #[allow(dead_code)]
   pub fn to_string(&self) -> String {
     use self::Type::*;
@@ -117,7 +119,7 @@ impl Type {
       Const(c) => c.to_string(),
       Var(v) => format!("t_{}", v.0),
       Arrow { params, box ref ret } => {
-        if params.len() == 0 {
+        if params.is_empty() {
           format!("-> {}", ret.to_string())
         } else {
           let mut buf = String::new();
@@ -128,9 +130,10 @@ impl Type {
           buf
         }
       },
-      Compound { .. } => format!("<some compound type>")
+      Compound { .. } => "<some compound type>".to_string()
     }
   }
+    */
 
   fn from_string(string: &str) -> Option<Type> {
     Some(match string {
@@ -256,7 +259,7 @@ impl<'a> TypeContext<'a> {
     use self::TypeIdentifier::*;
     Ok(match name {
       Singleton(TypeSingletonName { name,.. }) =>  {
-        match Type::from_string(&name) {
+        match Type::from_string(name) {
           Some(ty) => ty,
           None => return TypeError::new(format!("Unknown type name: {}", name))
         }
@@ -279,7 +282,7 @@ impl<'a> TypeContext<'a> {
   fn statement(&mut self, statement: &Statement) -> InferResult<Type> {
     match &statement.kind {
       StatementKind::Expression(e) => self.expr(e),
-      StatementKind::Declaration(decl) => self.decl(&decl),
+      StatementKind::Declaration(decl) => self.decl(decl),
       StatementKind::Import(_) => Ok(ty!(Unit)),
       StatementKind::Module(_) => Ok(ty!(Unit)),
     }
@@ -287,12 +290,9 @@ impl<'a> TypeContext<'a> {
 
   fn decl(&mut self, decl: &Declaration) -> InferResult<Type> {
     use self::Declaration::*;
-    match decl {
-      Binding { name, expr, .. } => {
+    if let Binding { name, expr, .. } = decl {
         let ty = self.expr(expr)?;
         self.variable_map.insert(name.clone(), ty);
-      },
-      _ => (),
     }
     Ok(ty!(Unit))
   }
@@ -361,10 +361,11 @@ impl<'a> TypeContext<'a> {
     use self::IfExpressionBody::*;
     match (discriminator, body) {
       (Some(expr), SimpleConditional{ then_case, else_case }) => self.handle_simple_if(expr, then_case, else_case),
-      _ => TypeError::new(format!("Complex conditionals not supported"))
+      _ => TypeError::new("Complex conditionals not supported".to_string())
     }
   }
 
+  #[allow(clippy::ptr_arg)]
   fn handle_simple_if(&mut self, expr: &Expression, then_clause: &Block, else_clause: &Option<Block>) -> InferResult<Type> {
     let t1 = self.expr(expr)?;
     let t2 = self.block(then_clause)?;
@@ -377,6 +378,7 @@ impl<'a> TypeContext<'a> {
     self.unify(t2, t3)
   }
 
+  #[allow(clippy::ptr_arg)]
   fn lambda(&mut self, params: &Vec<FormalParam>, type_anno: &Option<TypeIdentifier>, _body: &Block) -> InferResult<Type> {
     let argument_types: InferResult<Vec<Type>> = params.iter().map(|param: &FormalParam| {
       if let FormalParam { anno: Some(type_identifier), ..  } = param {
@@ -394,7 +396,7 @@ impl<'a> TypeContext<'a> {
     Ok(ty!(argument_types, ret_type))
   }
 
-  fn call(&mut self, f: &Expression, args: &Vec<InvocationArgument>) -> InferResult<Type> {
+  fn call(&mut self, f: &Expression, args: &[ InvocationArgument ]) -> InferResult<Type> {
     let tf = self.expr(f)?;
     let arg_types: InferResult<Vec<Type>> = args.iter().map(|ex| self.invoc(ex)).collect();
     let arg_types = arg_types?;
@@ -410,10 +412,11 @@ impl<'a> TypeContext<'a> {
         t_ret.clone()
       },
       Type::Arrow { .. } => return TypeError::new("Wrong length"),
-      _ => return TypeError::new(format!("Not a function"))
+      _ => return TypeError::new("Not a function".to_string())
     })
   }
 
+  #[allow(clippy::ptr_arg)]
   fn block(&mut self, block: &Block) -> InferResult<Type> {
     let mut output = ty!(Unit);
     for statement in block.iter() {
@@ -438,26 +441,26 @@ impl<'a> TypeContext<'a> {
       (Const(ref c1), Const(ref c2)) if c1 == c2 => Ok(Const(c1.clone())), //choice of c1 is arbitrary I *think*
       (a @ Var(_), b @ Const(_)) => self.unify(b, a),
       (Const(ref c1), Var(ref v2)) => {
-        self.unification_table.unify_var_value(v2.clone(), Some(c1.clone()))
+        self.unification_table.unify_var_value(*v2, Some(c1.clone()))
           .or_else(|_| TypeError::new(format!("Couldn't unify {:?} and {:?}", Const(c1.clone()), Var(*v2))))?;
         Ok(Const(c1.clone()))
       },
       (Var(v1), Var(v2)) => {
         //TODO add occurs check
-        self.unification_table.unify_var_var(v1.clone(), v2.clone())
+        self.unification_table.unify_var_var(v1, v2)
           .or_else(|e| {
             println!("Unify error: {:?}", e);
             TypeError::new(format!("Two type variables {:?} and {:?} couldn't unify", v1, v2))
           })?;
-        Ok(Var(v1.clone())) //arbitrary decision I think
+        Ok(Var(v1)) //arbitrary decision I think
       },
       (a, b) => TypeError::new(format!("{:?} and {:?} do not unify", a, b)),
     }
   }
 
   fn fresh_type_variable(&mut self) -> TypeVar {
-    let new_type_var = self.unification_table.new_key(None);
-    new_type_var
+    
+    self.unification_table.new_key(None)
   }
 }
 
@@ -468,7 +471,7 @@ mod typechecking_tests {
   macro_rules! assert_type_in_fresh_context {
     ($string:expr, $type:expr) => {
       let mut tc = TypeContext::new();
-      let ref ast = crate::util::quick_ast($string);
+      let ast = &crate::util::quick_ast($string);
       let ty = tc.typecheck(ast).unwrap();
       assert_eq!(ty, $type)
     }

schala-lang/language/src/util.rs

@@ -4,7 +4,7 @@ use std::cmp::Eq;
 use std::ops::Deref;
 
 pub fn deref_optional_box<T>(x: &Option<Box<T>>) -> Option<&T> {
-  x.as_ref().map(|b: &Box<T>| Deref::deref(b))
+  x.as_ref().map(Deref::deref)
 }
 
 #[derive(Default, Debug)]