2 * Copyright (C) 2013 Red Hat Inc.
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
19 (* For general information about camlp4, see:
20 * http://brion.inria.fr/gallium/index.php/Camlp4
22 * For information about quotations, see:
23 * http://brion.inria.fr/gallium/index.php/Quotation
32 let locfail _loc msg = Loc.raise _loc (Failure msg)
34 (* 'expr' is a function expression (RHS of a binding). It has the
35 * form 'fun a -> fun b -> ...'. Return the parameters and the body of
38 let rec function_parameters = function
39 (* fun patt -> expr *)
40 | ExFun (_loc, McArr (_ploc, param, ExNil _, expr)) ->
41 let params, body = function_parameters expr in
42 ((_ploc, param) :: params), body
43 (* patt when expr -> expr *)
44 | ExFun (_loc, McArr (_, _, _, expr)) ->
45 locfail _loc "not supported: goal function uses when-clause"
48 (* Define one or more 'let [rec] goal ... [and ...]' expressions.
50 * 'r' is Some _ if the rec keyword was defined. 'lets' is the list
53 let generate_let_goal _loc (r : rec_flag) (lets : binding) =
54 (* lets might be a single binding, or multiple bindings using BiAnd
55 * ('let .. and'). Rewrite each individual goal in the list.
57 let rec rewrite = function
58 | BiNil _loc -> BiNil _loc
60 (* let goal left = ... and right = ... *)
61 | BiAnd (_loc, left, right) ->
62 BiAnd (_loc, rewrite left, rewrite right)
64 (* let goal name = expr *)
65 | BiEq (_loc, PaId (_, (IdLid (_, name))), expr) ->
66 (* Rename the function to goal_<name>. *)
67 let gname = "goal_" ^ name in
69 (* Split the function into parameters and body. *)
70 let params, body = function_parameters expr in
73 locfail _loc "goal must have some parameters; you probably want to put '()' here";
75 (* Put a try-clause around the body. *)
76 let body = <:expr< try $body$ with Goal_result Goal_OK -> () >> in
78 (* Recreate the function with parameters. *)
81 fun (_ploc, param) rest ->
82 ExFun (_loc, McArr (_ploc, param, ExNil _ploc, rest))
85 <:binding< $lid:gname$ = $expr$ >>
87 locfail _loc "cannot parse 'let goal' expression"
89 let lets = rewrite lets in
91 (* let [rec] ... and ... in () *)
92 Ast.StVal (_loc, r, lets)
94 (* Rewrite 'require (name args...)' as 'require (goal_name args)'.
95 * 'expr' is a function call.
97 let generate_require _loc expr =
98 (* Note that 'f a b c' is parsed as '((f a) b) c' so the actually
99 * function name is buried deeply in the tree. Rewrite the name.
101 let rec rewrite = function
102 | ExApp (_loc, ExId (_loc1, IdLid (_loc2, name)), right) ->
103 let gname = "goal_" ^ name in
104 ExApp (_loc, ExId (_loc1, IdLid (_loc2, gname)), right)
105 | ExApp (_loc, (ExApp _ as expr), right) ->
106 ExApp (_loc, rewrite expr, right)
108 locfail _loc "require (...) expression must contain a call to a goal"
110 let expr = rewrite expr in
111 <:expr< Goaljobs.require ($expr$) >>
116 GLOBAL: expr str_item;
118 (* Rewrite 'require (name args...)'. *)
119 expr: LEVEL "apply" [
120 [ "require"; e = expr ->
121 generate_require _loc e ]
124 (* "str_item" is a top level statement in an OCaml program. *)
125 str_item: LEVEL "top" [
126 [ "let"; r = opt_rec; "goal"; ls = binding ->
127 generate_let_goal _loc r ls ]