//
	// To mitigate this, each matched node n is wrapped in a ParenExpr,
	// so we can reliably replace n in-place by assigning ParenExpr.X.
	// It's safe to use ParenExpr here, because typecheck already
	// removed them all.

	var parens []*ir.ParenExpr
	var mark func(ir.Node) ir.Node
	mark = func(n ir.Node) ir.Node {
		if _, ok := n.(*ir.ParenExpr); ok {
			return n // already visited n.X before wrapping
		}

// license that can be found in the LICENSE file.

package astutil

import "go/ast"

// Unparen returns e with any enclosing parentheses stripped.
func Unparen(e ast.Expr) ast.Expr {
	for {
		p, ok := e.(*ast.ParenExpr)
		if !ok {
			return e
		}
		e = p.X
	}

		// case *Name:
		// case *BasicLit:
		case *CompositeLit:
			if n.Type != nil {
				m = n.Type
				continue
			}
			return n.Pos()
		case *KeyValueExpr:
			m = n.Key
		// case *FuncLit:
		// case *ParenExpr:
		case *SelectorExpr:
			m = n.X
		case *IndexExpr:
			m = n.X
		// case *SliceExpr:
		case *AssertExpr:
			m = n.X
		case *TypeSwitchGuard:
			if n.Lhs != nil {
				m = n.Lhs
				continue
			}

		Rbrace     token.Pos // position of "}"
		Incomplete bool      // true if (source) expressions are missing in the Elts list
	}

	// A ParenExpr node represents a parenthesized expression.
	ParenExpr struct {
		Lparen token.Pos // position of "("
		X      Expr      // parenthesized expression
		Rparen token.Pos // position of ")"
	}

		if n == nil {
			return
		}
		// Find pattern like (*a.b)(x)
		c, ok := n.(*ast.CallExpr)
		if !ok {
			return
		}
		if len(c.Args) != 1 {
			return
		}
		p, ok := c.Fun.(*ast.ParenExpr)
		if !ok {
			return
		}
		s, ok := p.X.(*ast.StarExpr)
		if !ok {
			return
		}
		t, ok := s.X.(*ast.SelectorExpr)
		if !ok {
			return
		}
		pkg, ok := t.X.(*ast.Ident)

			// pretend this is an *ast.ParenExpr and do nothing.
			break
		}
		h4, h5, mp := walkBinary(l)
		has4 = has4 || h4
		has5 = has5 || h5
		maxProblem = max(maxProblem, mp)
	}

	switch r := e.Y.(type) {
	case *ast.BinaryExpr:
		if r.Op.Precedence() <= e.Op.Precedence() {
			// parens will be inserted.
			// pretend this is an *ast.ParenExpr and do nothing.
			break
		}

	case *ast.KeyValueExpr:
		return 1 << nKeyValueExpr
	case *ast.LabeledStmt:
		return 1 << nLabeledStmt
	case *ast.MapType:
		return 1 << nMapType
	case *ast.Package:
		return 1 << nPackage
	case *ast.ParenExpr:
		return 1 << nParenExpr
	case *ast.RangeStmt:
		return 1 << nRangeStmt
	case *ast.ReturnStmt:
		return 1 << nReturnStmt
	case *ast.SelectStmt:
		return 1 << nSelectStmt
	case *ast.SelectorExpr:

		buf.WriteString(" literal)") // shortened

	case *ast.CompositeLit:
		WriteExpr(buf, x.Type)
		buf.WriteByte('{')
		if len(x.Elts) > 0 {
			buf.WriteString("…")
		}
		buf.WriteByte('}')

	case *ast.ParenExpr:
		buf.WriteByte('(')
		WriteExpr(buf, x.X)
		buf.WriteByte(')')

	case *ast.SelectorExpr:
		WriteExpr(buf, x.X)
		buf.WriteByte('.')
		buf.WriteString(x.Sel.Name)

	case *ast.LabeledStmt:
		children = append(children,
			tok(n.Colon, len(":")))

	case *ast.MapType:
		children = append(children,
			tok(n.Map, len("map")))

	case *ast.ParenExpr:
		children = append(children,
			tok(n.Lparen, len("(")),
			tok(n.Rparen, len(")")))

	case *ast.RangeStmt:
		children = append(children,
			tok(n.For, len("for")),

			Walk(v, n.Elt)
		}

	case *FuncLit:
		Walk(v, n.Type)
		Walk(v, n.Body)

	case *CompositeLit:
		if n.Type != nil {
			Walk(v, n.Type)
		}
		walkList(v, n.Elts)

	case *ParenExpr:
		Walk(v, n.X)

	case *SelectorExpr:
		Walk(v, n.X)
		Walk(v, n.Sel)

	case *IndexExpr:
		Walk(v, n.X)
		Walk(v, n.Index)

	case *IndexListExpr:
		Walk(v, n.X)
		walkList(v, n.Indices)