From edf85b925939cb13ca82a10873ced589164391da Mon Sep 17 00:00:00 2001 From: Pierre Letouzey Date: Sat, 3 Jan 2015 18:50:53 +0100 Subject: 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. --- kernel/mod_typing.mli | 7 +------ 1 file changed, 1 insertion(+), 6 deletions(-) (limited to 'kernel/mod_typing.mli') diff --git a/kernel/mod_typing.mli b/kernel/mod_typing.mli index 21171705d..2e629a3b5 100644 --- a/kernel/mod_typing.mli +++ b/kernel/mod_typing.mli @@ -12,11 +12,7 @@ open Entries open Mod_subst open Names -(** Main functions for translating module entries - - Note : [module_body] and [module_type_body] obtained this way - won't have any [MEstruct] in their algebraic fields. -*) +(** Main functions for translating module entries *) val translate_module : env -> module_path -> inline -> module_entry -> module_body @@ -31,7 +27,6 @@ val translate_modtype : - The second output is the algebraic expression, kept for the extraction. It is never None when translating to a module, but for module type it could not be contain applications or functors. - Moreover algebraic expressions obtained here cannot contain [MEstruct]. *) type 'alg translation = -- cgit v1.2.3