let_chains: Remove ast::ExprKind::{IfLet, WhileLet} from visitors and introduce ::Let.

Author: Centril

src/librustc_save_analysis/dump_visitor.rs

@@ -1579,17 +1579,9 @@ impl<'l, 'tcx: 'l, 'll, O: DumpOutput + 'll> Visitor<'l> for DumpVisitor<'l, 'tc
                 self.visit_expr(subexpression);
                 visit::walk_block(self, block);
             }
-            ast::ExprKind::WhileLet(ref pats, ref subexpression, ref block, _) => {
+            ast::ExprKind::Let(ref pats, ref scrutinee) => {
                 self.process_var_decl_multi(pats);
-                debug!("for loop, walk sub-expr: {:?}", subexpression.node);
-                self.visit_expr(subexpression);
-                visit::walk_block(self, block);
-            }
-            ast::ExprKind::IfLet(ref pats, ref subexpression, ref block, ref opt_else) => {
-                self.process_var_decl_multi(pats);
-                self.visit_expr(subexpression);
-                visit::walk_block(self, block);
-                opt_else.as_ref().map(|el| self.visit_expr(el));
+                self.visit_expr(scrutinee);
             }
             ast::ExprKind::Repeat(ref element, ref count) => {
                 self.visit_expr(element);

src/libsyntax/mut_visit.rs

@@ -1131,28 +1131,20 @@ pub fn noop_visit_expr<T: MutVisitor>(Expr { node, id, span, attrs }: &mut Expr,
             vis.visit_ty(ty);
         }
         ExprKind::AddrOf(_m, ohs) => vis.visit_expr(ohs),
+        ExprKind::Let(pats, scrutinee) => {
+            visit_vec(pats, |pat| vis.visit_pat(pat));
+            vis.visit_expr(scrutinee);
+        }
         ExprKind::If(cond, tr, fl) => {
             vis.visit_expr(cond);
             vis.visit_block(tr);
             visit_opt(fl, |fl| vis.visit_expr(fl));
         }
-        ExprKind::IfLet(pats, expr, tr, fl) => {
-            visit_vec(pats, |pat| vis.visit_pat(pat));
-            vis.visit_expr(expr);
-            vis.visit_block(tr);
-            visit_opt(fl, |fl| vis.visit_expr(fl));
-        }
         ExprKind::While(cond, body, label) => {
             vis.visit_expr(cond);
             vis.visit_block(body);
             visit_opt(label, |label| vis.visit_label(label));
         }
-        ExprKind::WhileLet(pats, expr, body, label) => {
-            visit_vec(pats, |pat| vis.visit_pat(pat));
-            vis.visit_expr(expr);
-            vis.visit_block(body);
-            visit_opt(label, |label| vis.visit_label(label));
-        }
         ExprKind::ForLoop(pat, iter, body, label) => {
             vis.visit_pat(pat);
             vis.visit_expr(iter);

src/libsyntax/parse/classify.rs

@@ -14,11 +14,9 @@ use crate::ast;
 pub fn expr_requires_semi_to_be_stmt(e: &ast::Expr) -> bool {
     match e.node {
         ast::ExprKind::If(..) |
-        ast::ExprKind::IfLet(..) |
         ast::ExprKind::Match(..) |
         ast::ExprKind::Block(..) |
         ast::ExprKind::While(..) |
-        ast::ExprKind::WhileLet(..) |
         ast::ExprKind::Loop(..) |
         ast::ExprKind::ForLoop(..) |
         ast::ExprKind::TryBlock(..) => false,

src/libsyntax/visit.rs

@@ -719,6 +719,10 @@ pub fn walk_expr<'a, V: Visitor<'a>>(visitor: &mut V, expression: &'a Expr) {
             visitor.visit_expr(subexpression);
             visitor.visit_ty(typ)
         }
+        ExprKind::Let(ref pats, ref scrutinee) => {
+            walk_list!(visitor, visit_pat, pats);
+            visitor.visit_expr(scrutinee);
+        }
         ExprKind::If(ref head_expression, ref if_block, ref optional_else) => {
             visitor.visit_expr(head_expression);
             visitor.visit_block(if_block);
@@ -729,18 +733,6 @@ pub fn walk_expr<'a, V: Visitor<'a>>(visitor: &mut V, expression: &'a Expr) {
             visitor.visit_expr(subexpression);
             visitor.visit_block(block);
         }
-        ExprKind::IfLet(ref pats, ref subexpression, ref if_block, ref optional_else) => {
-            walk_list!(visitor, visit_pat, pats);
-            visitor.visit_expr(subexpression);
-            visitor.visit_block(if_block);
-            walk_list!(visitor, visit_expr, optional_else);
-        }
-        ExprKind::WhileLet(ref pats, ref subexpression, ref block, ref opt_label) => {
-            walk_list!(visitor, visit_label, opt_label);
-            walk_list!(visitor, visit_pat, pats);
-            visitor.visit_expr(subexpression);
-            visitor.visit_block(block);
-        }
         ExprKind::ForLoop(ref pattern, ref subexpression, ref block, ref opt_label) => {
             walk_list!(visitor, visit_label, opt_label);
             visitor.visit_pat(pattern);