private static BaseExpression?SmallestExponents(Number value)
{
var bestLength = int.MaxValue;
BaseExpression?best = null;
void Submit(BaseExpression exp)
{
if (exp.StaticEvaluate().Number != value)
{
return;
}
var length = exp.ToString().Length;
if (length < bestLength)
{
bestLength = length;
best = exp;
}
}
for (var idx = 1; idx < 320; idx++)
{
var b = idx / 10m;
try
{
var log = Math.Log((double)value, (double)b);
if (double.IsNaN(log))
{
continue;
}
var exp = new Exponent(new ConstantNumber((Number)b), new ConstantNumber((Number)log));
Submit(exp);
var integral = new Exponent(new ConstantNumber((Number)b), new ConstantNumber((Number)(int)Math.Round(log)));
var integralV = integral.StaticEvaluate().Number;
var integralE = value - integralV;
Submit(new Add(integral, new ConstantNumber(integralE)));
}
catch (OverflowException)
{
// If the calculation overflows then don't submit this case
}
}
return(best);
}
protected override BaseExpression Visit(ConstantNumber con)
{
if (con.Value.ToString().Length <= 3)
{
return(base.Visit(con));
}
var replacements = new[] {
SmallestExponents(con.Value),
BestFraction(con.Value),
};
var shortestLength = int.MaxValue;
BaseExpression?shortest = null;
foreach (var replacement in replacements)
{
if (replacement == null)
{
continue;
}
var l = replacement.ToString().Length;
if (l < shortestLength)
{
shortestLength = l;
shortest = replacement;
}
}
if (shortest != null && shortestLength < con.ToString().Length)
{
return(base.Visit(shortest));
}
return(base.Visit(con));
}
public override bool Equals(BaseExpression?other)
{
return(other is LessThanEqualTo a &&
a.Equals(this));
}
public override bool Equals(BaseExpression?other)
{
return(other is ConstantNumber num &&
num.Equals(this));
}
public override bool Equals(BaseExpression?other)
{
return(other is Not not &&
not.Equals(this));
}
public override bool Equals(BaseExpression?other)
{
return(other is Factorial fac &&
fac.Equals(this));
}
public override bool Equals(BaseExpression?other)
{
return(other is Variable var &&
var.Equals(this));
}
public override bool Equals(BaseExpression?other)
{
return(other is Increment a &&
a.Equals(this));
}
public override bool Equals(BaseExpression?other)
{
return(other is ConstantString str &&
str.Equals(this));
}
public override bool Equals(BaseExpression?other)
{
return(other is Sqrt sqrt &&
sqrt.Equals(this));
}
public override bool Equals(BaseExpression?other)
{
return(other is Cosine cos &&
cos.Equals(this));
}
public override bool Equals(BaseExpression? other)
{
return other is ErrorExpression a
&& a.Equals(this);
}
public override bool Equals(BaseExpression?other)
{
return(other is Abs abs &&
abs.Equals(this));
}
public override bool Equals(BaseExpression?other)
{
return(other is GreaterThan a &&
a.Equals(this));
}
public override bool Equals(BaseExpression?other)
{
return(other is ArcSine asin &&
asin.Equals(this));
}
public override bool Equals(BaseExpression?other)
{
return(other is ArcCos acos &&
acos.Equals(this));
}
public override bool Equals(BaseExpression?other)
{
return(other is ArcTan atan &&
atan.Equals(this));
}
public override bool Equals(BaseExpression?other)
{
return(other is Divide a &&
a.Equals(this));
}
public override bool Equals(BaseExpression?other)
{
return(other is Negate neg &&
neg.Equals(this));
}
public override bool Equals(BaseExpression?other)
{
return(other is Bracketed brk &&
brk.Equals(this));
}
public override bool Equals(BaseExpression?other)
{
return(other is PostIncrement post &&
post.Equals(this));
}
public abstract bool Equals(BaseExpression?other);
public override bool Equals(BaseExpression?other)
{
return(other is Sine sine &&
sine.Equals(this));
}
public override bool Equals(BaseExpression?other)
{
return(other is PreDecrement pre &&
pre.Equals(this));
}
public override bool Equals(BaseExpression?other)
{
return(other is Tangent tan &&
tan.Equals(this));
}