code-blocks.rb(main):001:0> #! /usr/bin/env ruby
code-blocks.rb(main):002:0* 
code-blocks.rb(main):003:0* # Simple passing of code block
code-blocks.rb(main):004:0* 3.times { puts 'Repeated string' }
Repeated string
Repeated string
Repeated string
=> 3
code-blocks.rb(main):005:0> 
code-blocks.rb(main):006:0* # Extending a class
code-blocks.rb(main):007:0* class Fixnum
code-blocks.rb(main):008:1> 	def my_times
code-blocks.rb(main):009:2> 		# We're in a number, so store it as an iterator
code-blocks.rb(main):010:2* 		i = self
code-blocks.rb(main):011:2> 		until i == 0
code-blocks.rb(main):012:3> 			i = i - 1
code-blocks.rb(main):013:3> 			# Magic happens here!
code-blocks.rb(main):014:3* 			# Yield normally yields a value, but somehow we're executing a block…
code-blocks.rb(main):015:3* 			yield
code-blocks.rb(main):016:3> 		end
code-blocks.rb(main):017:2> 	end
code-blocks.rb(main):018:1> end
=> :my_times
code-blocks.rb(main):019:0> 
code-blocks.rb(main):020:0* 3.my_times { puts 'My repeated string' }
My repeated string
My repeated string
My repeated string
=> nil
code-blocks.rb(main):021:0> 
code-blocks.rb(main):022:0* # Blocks are objects, if you do it right - https://www.ruby-forum.com/topic/49018
code-blocks.rb(main):023:0* my_block = proc { puts 'I am a block' }
=> #<Proc:0x000000017361e8@code-blocks.rb:23>
code-blocks.rb(main):024:0> puts my_block.class
Proc
=> nil
code-blocks.rb(main):025:0> 
code-blocks.rb(main):026:0* # Blocks can be passed around - "&var" says "this is a block"
code-blocks.rb(main):027:0* def call_block(&block)
code-blocks.rb(main):028:1> 	block.call
code-blocks.rb(main):029:1> end
=> :call_block
code-blocks.rb(main):030:0> def pass_block(&block)
code-blocks.rb(main):031:1> 	call_block(&block)
code-blocks.rb(main):032:1> end
=> :pass_block
code-blocks.rb(main):033:0> pass_block { puts 'Inline block' }
Inline block
=> nil
code-blocks.rb(main):034:0> pass_block &my_block
I am a block
=> nil
code-blocks.rb(main):035:0> 
code-blocks.rb(main):036:0* # Without the "&" we get "wrong number of arguments (1 for 0)" because
code-blocks.rb(main):037:0* # a block and an argument are different somehow. This is *not* 
code-blocks.rb(main):038:0* # because we were trying to call "my_block" and pass what it returned (nil).
code-blocks.rb(main):039:0* # I tried. Calling a block definitely needs ".call"
code-blocks.rb(main):040:0* #
code-blocks.rb(main):041:0* # This page (https://mixandgo.com/blog/mastering-ruby-blocks-in-less-than-5-minutes)
code-blocks.rb(main):042:0* # makes it cleared: ANY method can take a block independent of its arguments.
code-blocks.rb(main):043:0* # That means that this works:
code-blocks.rb(main):044:0* def pass_var_block(block)
code-blocks.rb(main):045:1> 	call_block(&block)
code-blocks.rb(main):046:1> end
=> :pass_var_block
code-blocks.rb(main):047:0> 
code-blocks.rb(main):048:0* pass_var_block my_block
I am a block
=> nil
code-blocks.rb(main):049:0>