Question

I am working with a generic data structure, say MyGeneric<Type>. There is a case where I have to iterate over all the values it holds

The code I am trying to do.

for ( all the keys in myGeneric ) {     // do lot of stuff here  } 

Now the generic can hold base type as double and string and it can hold some user-defined type also. There is a particular situation where I have to some specific work depending upon the type of the generic.

so the final code block looks something like this

for( all the keys in myGeneric ) {     if key is type foo then          //do foo foo      else if key is of type bar          //do bar bar  } 

Now, as complexity sensitive as I am I do not like to have an if condition in the for loop. So the next solution I did was

if myGeneric is of type foo      call fooIterator(myGeneric)  if myGenric is of type bar      call barItetrator(myGeneric)   function FooIterator() {     // .....     // foo work      //...... }  function BarItetrator() {     // .....     // bar work      //...... } 

Then again when somebody sees my code then I am quite sure that they will shout where is the ‘refactoring’.

What is the ideal thing to do in this situation ?

Thanks.

Answer 1

Well, you could use the Linq OfType<T> method, and multiple loops?

foreach(Foo foo in list.OfType<Foo>()) {   // } foreach(Bar bar in list.OfType<Bar>()) {   // } 

Beyond that, you’re into conditional statements. I did look at this here in relation to F#, which does this more cleanly.

As an aside; if this was using PushLINQ (in MiscUtil) you could do this in a single iteration, by pushing the different types through different branches – not sure it warrants it just for this, though.