// (- 123)の計算
public override Result VisitExpr_unary([NotNull] calcParser.Expr_unaryContext context)
{
var(Suc, type, value) = base.VisitExpr_unary(context);
if (!Suc)
{
return(DefaultResult);
}
try
{
checked
{
switch (context.op.Type)
{
case calcParser.PLUS: return(new Result(true, type, value));
case calcParser.MINUS:
if (type == CalcRule.CalcInt)
{
return(new Result(true, type, GetValInt(type, value) * -1));
}
else
{
return(new Result(true, type, GetValFloat(type, value) * -1));
}
default: return(DefaultResult);
}
}
}
catch (OverflowException)
{
return(new Result(false, CalcRule.None, (int)ErrString.ErrID.OverFlow));
}
}
/// <summary>
/// Visit a parse tree produced by the <c>expr_unary</c>
/// labeled alternative in <see cref="calcParser.expr"/>.
/// <para>
/// The default implementation returns the result of calling <see cref="AbstractParseTreeVisitor{Result}.VisitChildren(IRuleNode)"/>
/// on <paramref name="context"/>.
/// </para>
/// </summary>
/// <param name="context">The parse tree.</param>
/// <return>The visitor result.</return>
public virtual Result VisitExpr_unary([NotNull] calcParser.Expr_unaryContext context)
{
return(VisitChildren(context));
}
