Procs, Methods, Blocks, Functions

gistfile1.txt

# def log_before_doing()
#     puts "About to do stuff in a block."
#     yield
#     yield
# end

# log_before_doing() { puts "Doin' stuff in a block."}

# def do_ten_times()
#     10.times { yield }
# end

# do_ten_times() { puts "YEAH!" }

# def do_ten_times_explicit(&block)
#     10.times { block.call() }
# end

# do_ten_times_explicit() { puts "This is a block." }

# puts

# def tell_me_about_the_block(&some_block)
#     puts some_block.inspect
#     puts some_block.class
#     if some_block
#         some_block.call()
#     end
#     return 1
# end

# puts tell_me_about_the_block(){ puts "YO!" }.class

# def call_block_if_given
#     if block_given?
#         yield
#     end
# end

# call_block_if_given()

# tell_me_about_the_block() { puts "This is also a block." }

# Can't do this:
#some_block = { puts "I'm in a block!" }

# CAN do this:
# some_block = Proc.new { puts "I'm in a block!" }
# some_block.call()

# tell_me_about_the_block(some_block)

# [1, 2, 3].each do |item|
#     puts("Iterating over #{item}...")
# end

# [1, 2, 3].each(&Proc.new { |item| puts("Iterating over #{item}...") })

# def my_each(items, &proc)
#     amt_items = items.size()
#     counter = 0
#     while counter < amt_items
#         current_item = items[counter]
#         proc.call(current_item)
#         counter = counter + 1
#     end
# end

# def my_each(items)
#     amt_items = items.size()
#     counter = 0
#     while counter < amt_items
#         current_item = items[counter]
#         yield(current_item)
#         counter = counter + 1
#     end
#    items
# end

# my_each([1, 2, 3]) do |item|
#     puts("Iterating over #{item}...")
# end

# def do_for_all_instructors
#     yield("Phil")
#     yield("Max")
#     yield("David")
# end

# def do_for_all_instructors(&block)
#     block.call("Phil", "GA lobby")
#     block.call("Max", "Mars")
#     block.call("David", "Union Square")
# end

# do_for_all_instructors do |instructor, location|
#     puts "Hang out with #{instructor} (after the course) at #{location}."
# end

def get_maxs_age
    log_file = "age_query.log"
    log = File.open(log_file, 'a+')
    log.puts("#{Time.now}: Someone asked for Max's age.")
    return 500
end

# Input: FixNum
# Side Effect:
# - Puts 5 lines
# def ask_about_maxs_age_without_call(age)
#     puts age.class
#     puts age.inspect
#     puts "Bill asks; it's #{age}."
#     puts "John asks; it's #{age}."
#     puts "Rick asks; it's #{age}."
# end

#ask_about_maxs_age_without_call(get_maxs_age())

# Input: Proc
# Side Effect:
# - Puts 5 lines
# - Calls the "get_maxs_age" method Three times
def ask_about_maxs_age_with_call(get_age)
    puts get_age.class
    puts get_age.inspect
    puts "Bill asks; it's #{get_age.call}."
    puts "John asks; it's #{get_age.call}."
    puts "Rick asks; it's #{get_age.call}."
end

ask_about_maxs_age_with_call(method(:get_maxs_age))

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def my_map(items)
  amt_items = items.size()
  counter = 0
  new_arr = []
  while counter < amt_items
    current_item = items[counter]
    new_arr << yield(current_item)
    counter += 1
  end
  return new_arr
end
# TESTING IN PRY WITH CODE BELOW:
# new_array = my_map([items]) { items * 2 }

# OTHER WAY
def my_map(items)
  amt_items = items.size()
  counter = 0

  new_arr = []

  while counter < amt_items
    current_item = items[counter]
    new_arr << yield(current_item)
    counter += 1
  end

  return new_arr
end
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