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| author |  Pierre Letouzey <pierre.letouzey@inria.fr> | 2017-02-04 01:01:05 +0100 |
|---|---|---|
| committer | Pierre Letouzey <pierre.letouzey@inria.fr> | 2017-02-07 22:56:56 +0100 |
| commit | 5484ba750ef4526dde29ffc1474ca5d145f3ec04 (patch) | |
| tree | b3e03ad86078a0b6a4ddcd5204f0977d3e16a5b4 /plugins/extraction | |
| parent | 93fb83feefbed738aae98b23715465d8b92816da (diff) | |
Extraction: fix complexity issue #5310
A double call to pp_module_type inside Ocaml.pp_specif was
causing an complexity blowup when pretty-printing heavily modular
extracted code.
I wasn't able to figure out why this double call is there. It could
be the leftover of some intermediate work in 2007 before commit 350398eae
(which introduced global printing phases Pre/Impl/Intf).
Anyway I'm reasonably sure that today these two pp_module_type calls produce
the exact same pretty-printed signature (even if there's a large bunch of
imperative states around). Moreover, this duplicated signature is actually
slightly wrong: when we alias a module M with a unambiguous name like Coq__123,
the type of Coq__123 should not be an exact copy of the type of M, but rather
a "strengthened" version of it (with equality between inductive types).
So the best solution is now to use this funny feature of OCaml introduced in 3.12 :
module Coq__123 : module type of struct include M end
This "module type of struct include" is slightly awkward, but short, correct,
and trivial to produce :-). And I doubt anybody will object to the (rare) use
of some 3.12 features in extracted code of 2017...
Diffstat (limited to 'plugins/extraction')
| -rw-r--r-- | plugins/extraction/ocaml.ml | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/plugins/extraction/ocaml.ml b/plugins/extraction/ocaml.ml index 1c29a9bc2..5d10cb939 100644 --- a/plugins/extraction/ocaml.ml +++ b/plugins/extraction/ocaml.ml @@ -618,12 +618,13 @@ let rec pp_specif = function with Not_found -> pp_spec s) | (l,Smodule mt) -> let def = pp_module_type [] mt in - let def' = pp_module_type [] mt in let name = pp_modname (MPdot (top_visible_mp (), l)) in hov 1 (str "module " ++ name ++ str " :" ++ fnl () ++ def) ++ (try let ren = Common.check_duplicate (top_visible_mp ()) l in - fnl () ++ hov 1 (str ("module "^ren^" :") ++ fnl () ++ def') + fnl () ++ + hov 1 (str ("module "^ren^" :") ++ spc () ++ + str "module type of struct include " ++ name ++ str " end") with Not_found -> Pp.mt ()) | (l,Smodtype mt) -> let def = pp_module_type [] mt in |