I was looking for something like FirstOrDefault* from .NET in phobos. For example, I have this piece of code:

string findBobOrReturnNull(string[] names)
{
    auto r = names.find("bob");
    if(r.empty) return null;
    return r.front;
}

assert(findBobOrReturnNull(["alice", "bob"]) == "bob");
assert(findBobOrReturnNull(["alice"]) is null);

How can I turn that into something like this, or is there another idiomatic way to write it as a single expression?

string findBobOrReturnNull(string[] names)
{
    return names.find("bob").firstOrDefault;
}

* https://msdn.microsoft.com/en-us/library/bb340482%28v=vs.110%29.aspx

On Friday, 2 September 2016 at 06:56:07 UTC, Lutger wrote:
>

You could do:
names.find("bob").chain(only(``)).front;
It's not very expressive though.

On Friday, 2 September 2016 at 06:56:07 UTC, Lutger wrote:
> I was looking for something like FirstOrDefault* from .NET in phobos. For example, I have this piece of code:
>
> string findBobOrReturnNull(string[] names)
> {
>     auto r = names.find("bob");
>     if(r.empty) return null;
>     return r.front;
> }
>
> assert(findBobOrReturnNull(["alice", "bob"]) == "bob");
> assert(findBobOrReturnNull(["alice"]) is null);
>
> How can I turn that into something like this, or is there another idiomatic way to write it as a single expression?
>
> string findBobOrReturnNull(string[] names)
> {
>     return names.find("bob").firstOrDefault;
> }
>
> * https://msdn.microsoft.com/en-us/library/bb340482%28v=vs.110%29.aspx

ElementType!R firstOrDefault(R)(R r, ElementType!R def = (ElementType!R).init)
       if(isInputRange!R)
{
    if(r.empty) return def;
    return r.front;
}