From d0d6af3c16e970367b5f7a7c7a1066484e4e60a2 Mon Sep 17 00:00:00 2001 From: Michel Mauny Date: Wed, 18 Jun 2008 15:35:02 +0000 Subject: [PATCH] Remove restrictions to stream concatenation, and use Lazy.t for the argument of the Slazy data constructor. Affected files: stdlib/{stream.ml,.depend,Makefile} git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@8893 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02 --- stdlib/.depend | 2 +- stdlib/Makefile | 4 +-- stdlib/stream.ml | 92 +++++++++++++++++++++++++++--------------------- 3 files changed, 54 insertions(+), 44 deletions(-) diff --git a/stdlib/.depend b/stdlib/.depend index fe9f5ad1f..fc51ab117 100644 --- a/stdlib/.depend +++ b/stdlib/.depend @@ -94,7 +94,7 @@ stack.cmo: list.cmi stack.cmi stack.cmx: list.cmx stack.cmi stdLabels.cmo: stringLabels.cmi listLabels.cmi arrayLabels.cmi stdLabels.cmi stdLabels.cmx: stringLabels.cmx listLabels.cmx arrayLabels.cmx stdLabels.cmi -stream.cmo: string.cmi obj.cmi list.cmi stream.cmi +stream.cmo: string.cmi obj.cmi list.cmi lazy.cmi stream.cmi stream.cmx: string.cmx obj.cmx list.cmx stream.cmi string.cmo: pervasives.cmi list.cmi char.cmi string.cmi string.cmx: pervasives.cmx list.cmx char.cmx string.cmi diff --git a/stdlib/Makefile b/stdlib/Makefile index 2be2ae7c8..e1ecfe032 100644 --- a/stdlib/Makefile +++ b/stdlib/Makefile @@ -29,13 +29,13 @@ OTHERS=array.cmo list.cmo char.cmo string.cmo sys.cmo \ hashtbl.cmo sort.cmo marshal.cmo obj.cmo \ int32.cmo int64.cmo nativeint.cmo \ lexing.cmo parsing.cmo \ - set.cmo map.cmo stack.cmo queue.cmo stream.cmo buffer.cmo \ + set.cmo map.cmo stack.cmo queue.cmo lazy.cmo stream.cmo buffer.cmo \ printf.cmo format.cmo scanf.cmo \ arg.cmo printexc.cmo gc.cmo \ digest.cmo random.cmo callback.cmo \ camlinternalOO.cmo oo.cmo camlinternalMod.cmo \ genlex.cmo weak.cmo \ - lazy.cmo filename.cmo complex.cmo \ + filename.cmo complex.cmo \ arrayLabels.cmo listLabels.cmo stringLabels.cmo moreLabels.cmo stdLabels.cmo all: stdlib.cma std_exit.cmo camlheader camlheader_ur diff --git a/stdlib/stream.ml b/stdlib/stream.ml index c9975c4a0..aa6a2a2ab 100644 --- a/stdlib/stream.ml +++ b/stdlib/stream.ml @@ -22,7 +22,7 @@ and 'a data = Sempty | Scons of 'a * 'a data | Sapp of 'a data * 'a data - | Slazy of (unit -> 'a data) + | Slazy of 'a data Lazy.t | Sgen of 'a gen | Sbuffio of buffio and 'a gen = { mutable curr : 'a option option; func : int -> 'a option } @@ -42,44 +42,54 @@ let fill_buff b = b.len <- input b.ic b.buff 0 (String.length b.buff); b.ind <- 0 ;; -let rec get_data = - function - Sempty -> None - | Scons (a, d) -> Some (a, d) - | Sapp (d1, d2) -> - begin match get_data d1 with - Some (a, d1) -> Some (a, Sapp (d1, d2)) - | None -> get_data d2 - end - | Slazy f -> - begin match f () with - Sgen _ | Sbuffio _ -> failwith "illegal stream concatenation" - | x -> get_data x - end - | Sgen _ | Sbuffio _ -> - failwith "illegal stream concatenation" +let rec get_data count d = match d with + (* Returns either Sempty or Scons(a, _) even when d is a generator + or a buffer. In those cases, the item a is seen as extracted from + the generator/buffer. + The count parameter is used for calling `Sgen-functions'. *) + Sempty | Scons (_, _) -> d + | Sapp (d1, d2) -> + begin match get_data count d1 with + Scons (a, d11) -> Scons (a, Sapp (d11, d2)) + | Sempty -> get_data count d2 + | _ -> assert false + end + | Sgen {curr = Some None; func = _ } -> Sempty + | Sgen ({curr = Some(Some a); func = f} as g) -> + g.curr <- None; Scons(a, d) + | Sgen g -> + begin match g.func count with + None -> g.curr <- Some(None); Sempty + | Some a -> Scons(a, d) + (* Warning: anyone using g thinks that an item has been read *) + end + | Sbuffio b -> + if b.ind >= b.len then fill_buff b; + if b.len == 0 then Sempty else + let r = Obj.magic (String.unsafe_get b.buff b.ind) in + (* Warning: anyone using g thinks that an item has been read *) + b.ind <- succ b.ind; Scons(r, d) + | Slazy f -> get_data count (Lazy.force f) ;; let rec peek s = - match s.data with - Sempty -> None - | Scons (a, _) -> Some a - | Sapp (_, _) -> - begin match get_data s.data with - Some (a, d) -> set_data s (Scons (a, d)); Some a - | None -> None - end - | Slazy f -> - begin match f () with - Sgen _ | Sbuffio _ -> failwith "illegal stream concatenation" - | d -> set_data s d; peek s - end - | Sgen {curr = Some a} -> a - | Sgen g -> let x = g.func s.count in g.curr <- Some x; x - | Sbuffio b -> - if b.ind >= b.len then fill_buff b; - if b.len == 0 then begin set_data s Sempty; None end - else Some (Obj.magic (String.unsafe_get b.buff b.ind)) + (* consult the first item of s *) + match s.data with + Sempty -> None + | Scons (a, _) -> Some a + | Sapp (_, _) -> + begin match get_data s.count s.data with + Scons(a, _) as d -> set_data s d; Some a + | Sempty -> None + | _ -> assert false + end + | Slazy f -> set_data s (Lazy.force f); peek s + | Sgen {curr = Some a} -> a + | Sgen g -> let x = g.func s.count in g.curr <- Some x; x + | Sbuffio b -> + if b.ind >= b.len then fill_buff b; + if b.len == 0 then begin set_data s Sempty; None end + else Some (Obj.magic (String.unsafe_get b.buff b.ind)) ;; let rec junk s = @@ -152,13 +162,13 @@ let icons i s = {count = 0; data = Scons (i, s.data)};; let ising i = {count = 0; data = Scons (i, Sempty)};; let lapp f s = - {count = 0; data = Slazy (fun _ -> Sapp ((f ()).data, s.data))} + {count = 0; data = Slazy (lazy(Sapp ((f ()).data, s.data)))} ;; -let lcons f s = {count = 0; data = Slazy (fun _ -> Scons (f (), s.data))};; -let lsing f = {count = 0; data = Slazy (fun _ -> Scons (f (), Sempty))};; +let lcons f s = {count = 0; data = Slazy (lazy(Scons (f (), s.data)))};; +let lsing f = {count = 0; data = Slazy (lazy(Scons (f (), Sempty)))};; let sempty = {count = 0; data = Sempty};; -let slazy f = {count = 0; data = Slazy (fun _ -> (f ()).data)};; +let slazy f = {count = 0; data = Slazy (lazy(f ()).data)};; (* For debugging use *) @@ -184,7 +194,7 @@ and dump_data f = print_string ", "; dump_data f d2; print_string ")" - | Slazy f -> print_string "Slazy" + | Slazy _ -> print_string "Slazy" | Sgen _ -> print_string "Sgen" | Sbuffio b -> print_string "Sbuffio" ;;