Avoiding introducing yet another convention in naming files.

6 files changed, 137 insertions, 0 deletions

diff --git a/plugins/derive/Derive.v b/plugins/derive/Derive.v
new file mode 100644
index 000000000..0d5a93b03
--- /dev/null
+++ b/plugins/derive/Derive.v
@@ -0,0 +1 @@
+Declare ML Module "derive_plugin".
\ No newline at end of file
diff --git a/plugins/derive/derive.ml b/plugins/derive/derive.ml
new file mode 100644
index 000000000..156c9771a
--- /dev/null
+++ b/plugins/derive/derive.ml
@@ -0,0 +1,104 @@
+(************************************************************************)
+(*  v      *   The Coq Proof Assistant  /  The Coq Development Team     *)
+(* <O___,, *   INRIA - CNRS - LIX - LRI - PPS - Copyright 1999-2012     *)
+(*   \VV/  **************************************************************)
+(*    //   *      This file is distributed under the terms of the       *)
+(*         *       GNU Lesser General Public License Version 2.1        *)
+(************************************************************************)
+
+let map_const_entry_body (f:Term.constr->Term.constr) (x:Entries.const_entry_body)
+    : Entries.const_entry_body =
+  Future.chain ~pure:true x begin fun ((b,ctx),fx) ->
+    (f b , ctx) , fx
+  end
+
+(** [start_deriving f suchthat lemma] starts a proof of [suchthat]
+    (which can contain references to [f]) in the context extended by
+    [f:=?x]. When the proof ends, [f] is defined as the value of [?x]
+    and [lemma] as the proof. *)
+let start_deriving f suchthat lemma =
+
+  let env = Global.env () in
+  let sigma = Evd.from_env env in
+  let kind = Decl_kinds.(Global,false,DefinitionBody Definition) in
+
+  (** create a sort variable for the type of [f] *)
+  (* spiwack: I don't know what the rigidity flag does, picked the one
+     that looked the most general. *)
+  let (sigma,f_type_sort) = Evd.new_sort_variable Evd.univ_flexible_alg sigma in
+  let f_type_type = Term.mkSort f_type_sort in
+  (** create the initial goals for the proof: |- Type ; |- ?1 ; f:=?2 |- suchthat *)
+  let goals =
+    let open Proofview in
+        TCons ( env , sigma , f_type_type , (fun sigma f_type ->
+        TCons ( env , sigma , f_type , (fun sigma ef ->
+        let env' = Environ.push_named (f , (Some ef) , f_type) env in
+        let evdref = ref sigma in
+        let suchthat = Constrintern.interp_type_evars env' evdref suchthat in
+        TCons ( env' , !evdref , suchthat , (fun sigma _ ->
+        TNil sigma))))))
+    in
+
+    (** The terminator handles the registering of constants when the proof is closed. *)
+    let terminator com =
+      let open Proof_global in
+      (** Extracts the relevant information from the proof. [Admitted]
+          and [Save] result in user errors. [opaque] is [true] if the
+          proof was concluded by [Qed], and [false] if [Defined]. [f_def]
+          and [lemma_def] correspond to the proof of [f] and of
+          [suchthat], respectively. *)
+      let (opaque,f_def,lemma_def) =
+        match com with
+        | Admitted -> Errors.error"Admitted isn't supported in Derive."
+        | Proved (_,Some _,_) ->
+            Errors.error"Cannot save a proof of Derive with an explicit name."
+        | Proved (opaque, None, obj) ->
+            match Proof_global.(obj.entries) with
+            | [_;f_def;lemma_def] ->
+                opaque , f_def , lemma_def
+            | _ -> assert false
+      in
+      (** The opacity of [f_def] is adjusted to be [false], as it
+          must. Then [f] is declared in the global environment. *)
+      let f_def = { f_def with Entries.const_entry_opaque = false } in
+      let f_def = Entries.DefinitionEntry f_def , Decl_kinds.(IsDefinition Definition) in
+      let f_kn = Declare.declare_constant f f_def in
+      let f_kn_term = Term.mkConst f_kn in
+      (** In the type and body of the proof of [suchthat] there can be
+          references to the variable [f]. It needs to be replaced by
+          references to the constant [f] declared above. This substitution
+          performs this precise action. *)
+      let substf c = Vars.replace_vars [f,f_kn_term] c in
+      (** Extracts the type of the proof of [suchthat]. *)
+      let lemma_pretype =
+        match Entries.(lemma_def.const_entry_type) with
+        | Some t -> t
+        | None -> assert false (* Proof_global always sets type here. *)
+      in
+      (** The references of [f] are subsituted appropriately. *)
+      let lemma_type = substf lemma_pretype in
+      (** The same is done in the body of the proof. *)
+      let lemma_body =
+        map_const_entry_body substf Entries.(lemma_def.const_entry_body)
+      in
+      let lemma_def = let open Entries in { lemma_def with
+        const_entry_body = lemma_body ;
+        const_entry_type = Some lemma_type ;
+        const_entry_opaque = opaque ; }
+      in
+      let lemma_def =
+        Entries.DefinitionEntry lemma_def ,
+        Decl_kinds.(IsProof Proposition)
+      in
+      ignore (Declare.declare_constant lemma lemma_def)
+      in
+
+  let () = Proof_global.start_dependent_proof lemma kind goals terminator in
+  let _ = Proof_global.with_current_proof begin fun _ p ->
+    Proof.run_tactic env Proofview.(tclFOCUS 1 2 shelve) p
+  end in
+  ()
+
+
+
+
diff --git a/plugins/derive/derive.mli b/plugins/derive/derive.mli
new file mode 100644
index 000000000..5157c4a27
--- /dev/null
+++ b/plugins/derive/derive.mli
@@ -0,0 +1,13 @@
+(************************************************************************)
+(*  v      *   The Coq Proof Assistant  /  The Coq Development Team     *)
+(* <O___,, *   INRIA - CNRS - LIX - LRI - PPS - Copyright 1999-2012     *)
+(*   \VV/  **************************************************************)
+(*    //   *      This file is distributed under the terms of the       *)
+(*         *       GNU Lesser General Public License Version 2.1        *)
+(************************************************************************)
+
+(** [start_deriving f suchthat lemma] starts a proof of [suchthat]
+    (which can contain references to [f]) in the context extended by
+    [f:=?x]. When the proof ends, [f] is defined as the value of [?x]
+    and [lemma] as the proof. *)
+val start_deriving : Names.Id.t -> Constrexpr.constr_expr -> Names.Id.t -> unit
diff --git a/plugins/derive/derive_plugin.mllib b/plugins/derive/derive_plugin.mllib
new file mode 100644
index 000000000..5ee0fc6da
--- /dev/null
+++ b/plugins/derive/derive_plugin.mllib
@@ -0,0 +1,2 @@
+Derive
+G_derive
diff --git a/plugins/derive/g_derive.ml4 b/plugins/derive/g_derive.ml4
new file mode 100644
index 000000000..0721c675f
--- /dev/null
+++ b/plugins/derive/g_derive.ml4
@@ -0,0 +1,16 @@
+(************************************************************************)
+(*  v      *   The Coq Proof Assistant  /  The Coq Development Team     *)
+(* <O___,, *   INRIA - CNRS - LIX - LRI - PPS - Copyright 1999-2012     *)
+(*   \VV/  **************************************************************)
+(*    //   *      This file is distributed under the terms of the       *)
+(*         *       GNU Lesser General Public License Version 2.1        *)
+(************************************************************************)
+
+(*i camlp4deps: "grammar/grammar.cma"  i*)
+
+let classify_derive_command _ = Vernacexpr.(VtStartProof ("Classic",Doesn'tGuaranteeOpacity,[]),VtLater)
+
+VERNAC COMMAND EXTEND Derive CLASSIFIED BY classify_derive_command
+| [ "Derive" ident(f) "SuchThat" constr(suchthat) "As" ident(lemma) ] ->
+     [ Derive.start_deriving f suchthat lemma ]
+END
diff --git a/plugins/derive/vo.itarget b/plugins/derive/vo.itarget
new file mode 100644
index 000000000..b48098219
--- /dev/null
+++ b/plugins/derive/vo.itarget
@@ -0,0 +1 @@
+Derive.vo
\ No newline at end of file