Skye Shaw's Ruby is the New Perl ™️ Guide to Procs and lambdas

skye-shaw-s-ruby-is-the-new-perl-guide-to-proc-and-lambda-s-and-some-random-shit.rb

# coding: utf-8
# Skye Shaw's Ruby is the New Perl ™️ Guide to Procs and lambda and Some Random Shit

lambda do
  p 1
  p 2
  p 3
end[]

lambda {
  p 1
  p 2
  p 3
}[]

-> {
  p 1
  p 2
  p 3
}[]

Proc.new do
  p 1
  p 2
  p 3
end[]

Proc.new {
  p 1
  p 2
  p 3
}[]

proc {
  p 1
  p 2
  p 3
}[]

proc do
  p 1
  p 2
  p 3
end[]

f = ->(n) { p n }  # same as lambda, almost same as Proc/proc

# Ruby is the new Perl, (too) many ways to do the same thing (in case you haven't noticed :)
f.call(1)
f.(1)
f[1]

begin
  f[]
rescue ArgumentError => e
  p "Here's what happens when you don't provide an arg to a lambda: #{e}"
end

f = Proc.new { |n| p n } # Proc don't give a fuck about args
f[]

def foo
  Proc.new { return 123 }[]
  p "return from a Proc returns from the method"
end

foo

def foo
  -> { return 123 }[]
  p "At my foo's end"
end

foo

f = ->(a, b = "bee") { p [a, b] }
f[2]
f[1, "not 2 bee"]

f = proc { |a, b = "bee"| p [a, b] }
# Same shit but args are requird
f[2]
f[1, "not 2 bee"]

# You can do some shit like list though:
def foo
  def bar
    123
  end
end

p foo.bar

# But it redefines bar every time  (at least on C Ruby/MRI)
def foohoo
  # Use global because of scope issues mentioned earlier
  $t = Time.new.usec
  def bar
    $t
  end
end

p foohoo.bar
p foohoo.bar