/// <summary>
/// comma → expression ("," expression)*
/// </summary>
/// <returns></returns>
private Expr Comma()
{
Expr expr = this.Expression();
while (match(COMMA))
{
// Token @operator = this.Previous();
Expr right = this.Expression();
expr = new Expr.Comma(expr, right);
}
return(expr);
}
public string VisitComma(Expr.Comma comma) => Format("comma", comma.Left, comma.Right);
public string VisitComma(Expr.Comma comma) => $"({comma.Left?.Accept(this)} , {comma.Right.Accept(this)})";
