return isTypeElem(x.X) || (x.Y != nil && isTypeElem(x.Y)) || x.Op == Tilde
	case *ParenExpr:
		return isTypeElem(x.X)
	}
	return false
}

// VarSpec = IdentifierList ( Type [ "=" ExpressionList ] | "=" ExpressionList ) .
func (p *parser) varDecl(group *Group) Decl {
	if trace {
		defer p.trace("varDecl")()
	}

	d := new(VarDecl)
	d.pos = p.pos()
	d.Group = group
	d.Pragma = p.takePragma()

right.
</p>

<pre class="ebnf">
ConstDecl      = "const" ( ConstSpec | "(" { ConstSpec ";" } ")" ) .
ConstSpec      = IdentifierList [ [ Type ] "=" ExpressionList ] .

IdentifierList = identifier { "," identifier } .
ExpressionList = Expression { "," Expression } .
</pre>

<p>
If the type is present, all constants take the type specified, and

right.
</p>

<pre class="ebnf">
ConstDecl      = "const" ( ConstSpec | "(" { ConstSpec ";" } ")" ) .
ConstSpec      = IdentifierList [ [ Type ] "=" ExpressionList ] .

IdentifierList = identifier { "," identifier } .
ExpressionList = Expression { "," Expression } .
</pre>

<p>
If the type is present, all constants take the type specified, and

// Common productions

// If lhs is set, result list elements which are identifiers are not resolved.
func (p *parser) parseExprList(lhs bool) (list []ast.Expr) {
	if p.trace {
		defer un(trace(p, "ExpressionList"))
	}

	list = append(list, p.parseExpr(lhs))
	for p.tok == token.COMMA {
		p.next()
		list = append(list, p.parseExpr(lhs))
	}

	return
}

// Common productions

// If lhs is set, result list elements which are identifiers are not resolved.
func (p *parser) parseExprList() (list []ast.Expr) {
	if p.trace {
		defer un(trace(p, "ExpressionList"))
	}

	list = append(list, p.parseExpr())
	for p.tok == token.COMMA {
		p.next()
		list = append(list, p.parseExpr())
	}

	return
}