public Expr VisitExprMinus(ExprMinus expr)
{
//x-(y+z) = x-y-z
if (expr.Right is ExprSubExpr subExprPlus && subExprPlus.SubExpression is ExprPlus plus)
{
return(new ExprMinus(new ExprMinus(expr.Left, plus.Left.ToSubExprIfComplex()), plus.Right.ToSubExprIfComplex()));
}
//(x+y)-z = x+y-z
if (expr.Left is ExprSubExpr subExprPlusL && subExprPlusL.SubExpression is ExprPlus plusL)
{
return(new ExprMinus(plusL, expr.Right));
}
//x-(y-z) = x-y+z
if (expr.Right is ExprSubExpr subExprMinus && subExprMinus.SubExpression is ExprMinus minus)
{
return(new ExprPlus(new ExprMinus(expr.Left, minus.Left.ToSubExprIfComplex()), minus.Right.ToSubExprIfComplex()));
}
//(x-y)-z = x-y-z
if (expr.Left is ExprSubExpr subExprMinusL && subExprMinusL.SubExpression is ExprMinus minusL)
{
return(new ExprMinus(minusL, expr.Right));
}
//x-(y*z) = x-y*z
if (expr.Right is ExprSubExpr subExprMul && subExprMul.SubExpression is ExprMul mul)
{
return(new ExprMinus(expr.Left, mul));
}
//(x*y)-z = x*y-z
if (expr.Left is ExprSubExpr subExprMulL && subExprMulL.SubExpression is ExprMul mulL)
{
return(new ExprMinus(mulL, expr.Right));
}
return(expr);
}
public Expr VisitExprMinus(ExprMinus expr)
{
var newLeft = expr.Left.Accept(this).Accept(this._modifier);
var newRight = expr.Right.Accept(this).Accept(this._modifier);
if (!ReferenceEquals(newLeft, expr.Left) || !ReferenceEquals(newRight, expr.Right))
{
return(new ExprMinus(newLeft, newRight));
}
return(expr);
}
public string VisitExprMinus(ExprMinus expr)
=> $"{expr.Left.Accept(this)}-{this.CheckPlusMinusParenthesizes(expr.Right)}";
public int VisitExprMinus(ExprMinus expr) => expr.Left.Accept(this) - expr.Right.Accept(this);