diff options
| author | Pierre Letouzey | 2015-01-03 18:50:53 +0100 |
|---|---|---|
| committer | Pierre Letouzey | 2015-01-11 09:56:39 +0100 |
| commit | edf85b925939cb13ca82a10873ced589164391da (patch) | |
| tree | 557735a0f0233f08a49e00169bb2f6afb6f695e2 /kernel/declarations.mli | |
| parent | d103a645df233dd40064e968fa8693607defa6a7 (diff) | |
Declarations.mli refactoring: module_type_body = module_body
After this commit, module_type_body is a particular case of module_type.
For a [module_type_body], the implementation field [mod_expr] is
supposed to be always [Abstract]. This is verified by coqchk, even
if this isn't so crucial, since [mod_expr] is never read in the case
of a module type.
Concretely, this amounts to the following rewrite on field names
for module_type_body:
- typ_expr --> mod_type
- typ_expr_alg --> mod_type_alg
- typ_* --> mod_*
and adding two new fields to mtb:
- mod_expr (always containing Abstract)
- mod_retroknowledge (always containing [])
This refactoring should be completely transparent for the user.
Pros: code sharing, for instance subst_modtype = subst_module.
Cons: a runtime invariant (mod_expr = Abstract) which isn't
enforced by typing. I tried a polymorphic typing of mod_expr,
to share field names while not having mtb = mb, but the OCaml
typechecker isn't clever enough with polymorphic mutual fixpoints,
and reject code sharing (e.g. between subst_modtype and subst_module).
In the future (with ocaml>=4), some GADT could maybe help here,
but for now the current solution seems good enough.
Diffstat (limited to 'kernel/declarations.mli')
| -rw-r--r-- | kernel/declarations.mli | 16 |
1 files changed, 5 insertions, 11 deletions
diff --git a/kernel/declarations.mli b/kernel/declarations.mli index 4f1672884f..2d5468ff18 100644 --- a/kernel/declarations.mli +++ b/kernel/declarations.mli @@ -251,17 +251,11 @@ and module_body = mod_delta : Mod_subst.delta_resolver; mod_retroknowledge : Retroknowledge.action list } -(** A [module_type_body] is similar to a [module_body], with - no implementation and retroknowledge fields *) - -and module_type_body = - { typ_mp : module_path; (** path of the module type *) - typ_expr : module_signature; (** expanded type *) - (** algebraic expression, kept if it's relevant for extraction *) - typ_expr_alg : module_expression option; - typ_constraints : Univ.constraints; - (** quotiented set of equivalent constants and inductive names *) - typ_delta : Mod_subst.delta_resolver} +(** A [module_type_body] is just a [module_body] with no + implementation ([mod_expr] always [Abstract]) and also + an empty [mod_retroknowledge] *) + +and module_type_body = module_body (** Extra invariants : |