Exercises from Chapter 14
Even Better Profiling
How you could do it:
def profile block_description, &block |
|
|
|
profiling_on = false |
|
if profiling_on |
start_time = Time.new |
block.call |
|
duration = Time.new - start_time |
puts "#{block_description}: #{duration} seconds" |
else |
block.call |
end |
end |
How I would do it:
$OPT_PROFILING_ON = false |
|
def profile block_description, &block |
if $OPT_PROFILING_ON |
start_time = Time.new |
block[] |
duration = Time.new - start_time |
puts "#{block_description}: #{duration} seconds" |
else |
block[] |
end |
end |
Grandfather Clock
How you could do it:
def grandfather_clock &block |
hour = Time.new.hour |
|
if hour >= 13 |
hour = hour - 12 |
end |
|
if hour == 0 |
hour = 12 |
end |
|
hour.times do |
block.call |
end |
end |
grandfather_clock do |
puts 'DONG!' |
end |
DONG! |
DONG! |
DONG! |
DONG! |
DONG! |
DONG! |
DONG! |
DONG! |
DONG! |
DONG! |
DONG! |
DONG! |
How I would do it:
def grandfather_clock &block |
hour = (Time.new.hour + 11)%12 + 1 |
|
hour.times(&block) |
end |
|
grandfather_clock { puts 'DONG!' } |
DONG! |
DONG! |
DONG! |
DONG! |
DONG! |
DONG! |
DONG! |
DONG! |
DONG! |
DONG! |
DONG! |
DONG! |
Program Logger
How you could do it:
def log desc, &block |
puts 'Beginning "' + desc + '"...' |
result = block.call |
puts '..."' + desc + '" finished, returning: ' + result.to_s |
end |
log 'outer block' do |
log 'some little block' do |
1**1 + 2**2 |
end |
|
log 'yet another block' do |
'!doof iahT ekil I'.reverse |
end |
|
'0' == 0 |
end |
Beginning "outer block"... |
Beginning "some little block"... |
..."some little block" finished, returning: 5 |
Beginning "yet another block"... |
..."yet another block" finished, returning: I like Thai food! |
..."outer block" finished, returning: false |
How I would do it:
def log desc, &block |
puts "Beginning #{desc.inspect}..." |
result = block[] |
puts "...#{desc.inspect} finished, returning: #{result}" |
end |
|
log 'outer block' do |
log 'some little block' do |
1**1 + 2**2 |
end |
|
log 'yet another block' do |
'!doof iahT ekil I'.reverse |
end |
|
'0' == 0 |
end |
Beginning "outer block"... |
Beginning "some little block"... |
..."some little block" finished, returning: 5 |
Beginning "yet another block"... |
..."yet another block" finished, returning: I like Thai food! |
..."outer block" finished, returning: false |
Better Program Logger
How you could do it:
$logger_depth = 0 |
|
def log desc, &block |
prefix = ' '*$logger_depth |
|
puts prefix + 'Beginning "' + desc + '"...' |
|
$logger_depth = $logger_depth + 1 |
result = block.call |
|
$logger_depth = $logger_depth - 1 |
puts prefix + '..."' + desc + '" finished, returning: ' + result.to_s |
end |
|
log 'outer block' do |
log 'some little block' do |
log 'teeny-tiny block' do |
'lOtS oF lOVe'.downcase |
end |
|
7 * 3 * 2 |
end |
|
log 'yet another block' do |
'!doof naidnI evol I'.reverse |
end |
|
'0' == "0" |
end |
Beginning "outer block"... |
Beginning "some little block"... |
Beginning "teeny-tiny block"... |
..."teeny-tiny block" finished, returning: lots of love |
..."some little block" finished, returning: 42 |
Beginning "yet another block"... |
..."yet another block" finished, returning: I love Indian food! |
..."outer block" finished, returning: true |
How I would do it:
$logger_depth = 0 |
|
def log desc, &block |
prefix = ' '*$logger_depth |
puts prefix+"Beginning #{desc.inspect}..." |
$logger_depth += 1 |
result = block[] |
$logger_depth -= 1 |
puts prefix+"...#{desc.inspect} finished, returning: #{result}" |
end |
|
log 'outer block' do |
log 'some little block' do |
log 'teeny-tiny block' do |
'lOtS oF lOVe'.downcase |
end |
7 * 3 * 2 |
end |
|
log 'yet another block' do |
'!doof naidnI evol I'.reverse |
end |
'0' == "0" |
end |
Beginning "outer block"... |
Beginning "some little block"... |
Beginning "teeny-tiny block"... |
..."teeny-tiny block" finished, returning: lots of love |
..."some little block" finished, returning: 42 |
Beginning "yet another block"... |
..."yet another block" finished, returning: I love Indian food! |
..."outer block" finished, returning: true |
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