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Vývoj / Re:Jak funguje Call/CC?
« kdy: 09. 05. 2019, 15:58:50 »
...a ještě ilustrace toho, že kontinuace umožňuje se do jí reifikovaného stavu vrátit:
Kód: [Vybrat]
iex(28)> :mnesia.transaction(fn ->
...(28)> {rec, cont1} = :mnesia.select(:test, [{:_,[],[:'$_']}], 1, :read)
...(28)> IO.puts("rec1 = #{inspect rec}")
...(28)> IO.puts("cont1 = #{inspect cont1}")
...(28)> {rec, cont2} = :mnesia.select(cont1)
...(28)> IO.puts("rec2 = #{inspect rec}")
...(28)> IO.puts("cont2 = #{inspect cont2}")
...(28)> {rec, cont3} = :mnesia.select(cont1)
...(28)> IO.puts("rec3 = #{inspect rec}")
...(28)> IO.puts("cont3 = #{inspect cont3}")
...(28)> IO.puts("cont2 == cont3 = #{cont2 == cont3}")
...(28)> end)
rec1 = [{:test, :a, 1}]
cont1 = {:mnesia_select, :test, {:tid, 7, #PID<0.100.0>}, :nonode@nohost, :ram_copies, {#Reference<0.3882805345.2162294785.166659>, 161, 1, #Reference<0.3882805345.2162294787.167694>, [], 0}, [], :undefined, :undefined, [{:_, [], [:"$_"]}]}
rec2 = [{:test, :b, 2}]
cont2 = {:mnesia_select, :test, {:tid, 7, #PID<0.100.0>}, :nonode@nohost, :ram_copies, {#Reference<0.3882805345.2162294785.166659>, 162, 1, #Reference<0.3882805345.2162294787.167694>, [], 0}, [], :undefined, :undefined, [{:_, [], [:"$_"]}]}
rec3 = [{:test, :b, 2}]
cont3 = {:mnesia_select, :test, {:tid, 7, #PID<0.100.0>}, :nonode@nohost, :ram_copies, {#Reference<0.3882805345.2162294785.166659>, 162, 1, #Reference<0.3882805345.2162294787.167694>, [], 0}, [], :undefined, :undefined, [{:_, [], [:"$_"]}]}
cont2 == cont3 = true
