String.Empty returns Some

[tjidde-nl]

Hi,

I'm wondering, since I cant find it on the webs if this is intended or not.

If I have a piece of code where I set a String.Empty for example. If in my example the moon isn't blue it should return String.Empty.

var result = String.Empty if(MoonIsBlue){ result = GetMoonInfo(); } return result;
I would expect that as being NONE since it is an empty object. But the result I get is Some().

The reason I find this as unintended is that in your own docs you state NULL is the worst thing ever made in computer science.

I can't find the recommended way of handling this.

(I know in the code I made above I could be if == true return GetMoonInfo(); But there are use cases where during logic it is possible to set a string as empty.) Or you start with an empty string and do some logic that might not give value to the string with certain conditions.

[CK-LinoPro]

null and string.Empty are two distinctly different values.
Optional((string)null) will return None, while Optional(string.Empty) will return Some(string.Empty).
This is completely intentional since you might want to handle both cases separately.

If you want to filter for empty strings, you can do something like this:

string? someString;
var optionalString = Optional(someString).Filter(s => s != string.Empty);

[louthy]

This is the correct answer, but you can also use the built-in: notEmpty

var optionalString = Optional(someString).Filter(notEmpty);

Which will ignore white-space too.

Also:

"you state NULL is the worst thing ever made in computer science."

I think that's probably regular-expressions. null is a close second.