Ruby - Possible to pass a block as a param as an actual block to another function?

instance-eval, ruby

Solution

Yes. You can pass the block to the other method by prepending the block variable with an ampersand like so:

def foo &blk
  # now, blk is a variable bound to a block object
  bar &blk
end

The reason your are getting "class: Object" is that Ruby uses lexical scoping. This means that self in `puts "class: #{self.class}"` refers to `main`, the default context.

Problem

This is what I'm trying to do: ``` def call_block(in_class = "String", &block) instance = eval("#{in_class}.new") puts "instance class: #{instance.class}" instance.instance_eval{ block.call } end # --- TEST EXAMPLE --- # This outputs "class: String" every time "sdlkfj".instance_eval { puts "class: #{self.class}" } # This will only output "class: Object" every time # I'm trying to get this to output "class: String" though call_block("String") { puts "class: #{self.class}" } ``` On the line where it says "instance.instance_eval{ block.call }", I'm trying to find another way to make the new instance variable run instance eval on the block. The only way I can think of to get it to do that is to pass instance_eval the original block, not as a variable or anything, but as a real block like in the test example. Any tips?

Original source