deep copy
# let orig = Array.init 8 (fun _ -> Array.create 8 "x");; val orig : string array array = [|[|"x"; "x"; "x"; "x"; "x"; "x"; "x"; "x"|]; [|"x"; "x"; "x"; "x"; "x"; "x"; "x"; "x"|]; [|"x"; "x"; "x"; "x"; "x"; "x"; "x"; "x"|]; [|"x"; "x"; "x"; "x"; "x"; "x"; "x"; "x"|]; [|"x"; "x"; "x"; "x"; "x"; "x"; "x"; "x"|]; [|"x"; "x"; "x"; "x"; "x"; "x"; "x"; "x"|]; [|"x"; "x"; "x"; "x"; "x"; "x"; "x"; "x"|]; [|"x"; "x"; "x"; "x"; "x"; "x"; "x"; "x"|]|]
こんな配列を作っていて、これの複製を作りたい、かつその複製に対して変更を加える場合、Array.copyがそれらしく見えるものの、shallow copyなので複製に対する変更が元のarrayに影響する。
# let clone = Array.copy orig;; val clone : string array array = [|[|"x"; "x"; "x"; "x"; "x"; "x"; "x"; "x"|]; [|"x"; "x"; "x"; "x"; "x"; "x"; "x"; "x"|]; [|"x"; "x"; "x"; "x"; "x"; "x"; "x"; "x"|]; [|"x"; "x"; "x"; "x"; "x"; "x"; "x"; "x"|]; [|"x"; "x"; "x"; "x"; "x"; "x"; "x"; "x"|]; [|"x"; "x"; "x"; "x"; "x"; "x"; "x"; "x"|]; [|"x"; "x"; "x"; "x"; "x"; "x"; "x"; "x"|]; [|"x"; "x"; "x"; "x"; "x"; "x"; "x"; "x"|]|] # clone.(0).(0) <- "o";; - : unit = () # orig;; - : string array array = [|[|"o"; "x"; "x"; "x"; "x"; "x"; "x"; "x"|]; [|"x"; "x"; "x"; "x"; "x"; "x"; "x"; "x"|]; [|"x"; "x"; "x"; "x"; "x"; "x"; "x"; "x"|]; [|"x"; "x"; "x"; "x"; "x"; "x"; "x"; "x"|]; [|"x"; "x"; "x"; "x"; "x"; "x"; "x"; "x"|]; [|"x"; "x"; "x"; "x"; "x"; "x"; "x"; "x"|]; [|"x"; "x"; "x"; "x"; "x"; "x"; "x"; "x"|]; [|"x"; "x"; "x"; "x"; "x"; "x"; "x"; "x"|]|] #
普段、RubyではMarshal.load(Marshal.dump xxx)としているので、同じことがOCamlではできまいか？と思って
# let orig = Array.init 8 (fun _ -> Array.create 8 "x");; val orig : string array array = [|[|"x"; "x"; "x"; "x"; "x"; "x"; "x"; "x"|]; [|"x"; "x"; "x"; "x"; "x"; "x"; "x"; "x"|]; [|"x"; "x"; "x"; "x"; "x"; "x"; "x"; "x"|]; [|"x"; "x"; "x"; "x"; "x"; "x"; "x"; "x"|]; [|"x"; "x"; "x"; "x"; "x"; "x"; "x"; "x"|]; [|"x"; "x"; "x"; "x"; "x"; "x"; "x"; "x"|]; [|"x"; "x"; "x"; "x"; "x"; "x"; "x"; "x"|]; [|"x"; "x"; "x"; "x"; "x"; "x"; "x"; "x"|]|] # let clone = (Marshal.from_string (Marshal.to_string orig []) 0 : string array array);; val clone : string array array = [|[|"x"; "x"; "x"; "x"; "x"; "x"; "x"; "x"|]; [|"x"; "x"; "x"; "x"; "x"; "x"; "x"; "x"|]; [|"x"; "x"; "x"; "x"; "x"; "x"; "x"; "x"|]; [|"x"; "x"; "x"; "x"; "x"; "x"; "x"; "x"|]; [|"x"; "x"; "x"; "x"; "x"; "x"; "x"; "x"|]; [|"x"; "x"; "x"; "x"; "x"; "x"; "x"; "x"|]; [|"x"; "x"; "x"; "x"; "x"; "x"; "x"; "x"|]; [|"x"; "x"; "x"; "x"; "x"; "x"; "x"; "x"|]|] # clone.(0).(0) <- "o";; - : unit = () # orig;; - : string array array = [|[|"x"; "x"; "x"; "x"; "x"; "x"; "x"; "x"|]; [|"x"; "x"; "x"; "x"; "x"; "x"; "x"; "x"|]; [|"x"; "x"; "x"; "x"; "x"; "x"; "x"; "x"|]; [|"x"; "x"; "x"; "x"; "x"; "x"; "x"; "x"|]; [|"x"; "x"; "x"; "x"; "x"; "x"; "x"; "x"|]; [|"x"; "x"; "x"; "x"; "x"; "x"; "x"; "x"|]; [|"x"; "x"; "x"; "x"; "x"; "x"; "x"; "x"|]; [|"x"; "x"; "x"; "x"; "x"; "x"; "x"; "x"|]|] #
でけた
