Problem Statement

List the conditional structures offered by a programming language. See Wikipedia: conditionals for descriptions. Common conditional structures include if-then-else and switch. Less common are arithmetic if, ternary operator and Hash-based conditionals. Arithmetic if allows tight control over computed gotos, which optimizers have a hard time to figure out.

Let's start with the solution:

proc {PrintParity X}
   if {IsEven X} then
      {Show even}
   elseif {IsOdd X} then
      {Show odd}
   else
      {Show 'should not happen'}
   end
end

fun {Max X Y}
   if X > Y then X else Y end
end

fun {Fac X}
   case X of 0 then 1
   [] _ then X * {Fac X-1}
   end
end