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|
=begin
output:
A
block called 0
B
retrying
A
block called 1
B
comment:
Retry on Proc returns to the call-site that made the block, if the frame of the call-site is still alive.
=end
$i = 0;
def retry_proc *,&p
if ($i == 0)
puts "retrying '#{p}'"
$i = $i + 1
retry
end
end
def block_def
defp(puts('P')) {
puts "P block called"
}
defq(puts('Q')) {
puts "Q block called"
}
end
def defp *,&p
$p = p
end
def defq *,&q
$q = q
end
def g1 *,&x
puts '1.begin'
retry_proc puts('C'), &$p
puts '1.end'
ensure
puts '1.finally'
end
def g2 *,&x
puts '2.begin'
g1 puts('2.r'), &$p
puts '2.end'
ensure
puts '2.finally'
end
def g3 *,&x
puts '3.begin'
g2 puts('3.r'), &$p # jumps here, because this function's block differs from the one that is being retried
puts '3.end'
ensure
puts '3.finally'
end
def g4 *,&x
$p = x
puts '4.begin'
g3 puts('4.r'), &$q
puts '4.end'
ensure
puts '4.finally'
end
def g5 *,&x
puts '5.begin'
g4(puts('5.r')) { puts 'z' }
puts '5.end'
ensure
puts '5.finally'
end
block_def
g5
|
