X-Git-Url: http://git.annexia.org/?a=blobdiff_plain;f=src%2Feval.ml;h=24b04d435d0beecca0494cea483842406b0fa280;hb=refs%2Fheads%2Fmaster;hp=e29976934c5fc2280bfaa45d0a5ee0a2a082bf16;hpb=84972c63d0dbc5a0da05ae08a5b99a9ad81baadc;p=goals.git

diff --git a/src/eval.ml b/src/eval.ml
index e299769..24b04d4 100644
--- a/src/eval.ml
+++ b/src/eval.ml
@@ -17,8 +17,12 @@
  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  *)
 
+open Printf
+
 open Utils
 
+let pure_cache = Hashtbl.create 13
+
 let rec to_constant env = function
   | Ast.EConstant (loc, c) -> c
 
@@ -33,20 +37,38 @@ let rec to_constant env = function
      failwithf "%a: list found where constant expression expected"
        Ast.string_loc loc
 
-  | ECallGoal (loc, name, _) ->
-     failwithf "%a: cannot use goal ‘%s’ in constant expression"
-       Ast.string_loc loc name
+  | ECall (loc, name, args) ->
+     let expr = Ast.getvar env loc name in
+     (match expr with
+      | EGoalDefn _ ->
+         (* Goals don't return anything so they cannot be used in
+          * constant expressions.  Use a function instead.
+          *)
+         failwithf "%a: cannot use goal call ‘%s’ in shell expansion"
+           Ast.string_loc loc name
 
-  | ETacticCtor (loc, name, _) ->
-     failwithf "%a: cannot use tactic ‘%s’ in constant expression"
+      | EFuncDefn (loc, func) ->
+         to_constant env (call_function env loc name args func)
+
+      | _ ->
+         failwithf "%a: cannot use ‘%s’ in constant expression"
+           Ast.string_loc loc name
+     )
+
+  | EPredCtor (loc, name, _) ->
+     failwithf "%a: cannot use predicate ‘%s’ in constant expression"
        Ast.string_loc loc name
 
   | EGoalDefn (loc, _) ->
      failwithf "%a: cannot use goal in constant expression"
        Ast.string_loc loc
 
-  | ETacticDefn (loc, _) ->
-     failwithf "%a: cannot use tactic in constant expression"
+  | EFuncDefn (loc, _) ->
+     failwithf "%a: cannot use function in constant expression"
+       Ast.string_loc loc
+
+  | EPredDefn (loc, _) ->
+     failwithf "%a: cannot use predicate in constant expression"
        Ast.string_loc loc
 
 and substitute env loc substs =
@@ -61,7 +83,7 @@ and substitute env loc substs =
   ) substs;
   Buffer.contents b
 
-let rec to_shell_script env loc substs =
+and to_shell_script env loc substs =
   let b = Buffer.create 13 in
   List.iter (
     function
@@ -88,23 +110,91 @@ and expr_to_shell_string env = function
      (* These are shell quoted so we can just concat them with space. *)
      String.concat " " strs
 
-  | ECallGoal (loc, name, _) ->
-     failwithf "%a: cannot use goal ‘%s’ in shell expansion"
-       Ast.string_loc loc name
+  | ECall (loc, name, args) ->
+     let expr = Ast.getvar env loc name in
+     (match expr with
+      | EGoalDefn _ ->
+         (* Goals don't return anything so they cannot be used in
+          * shell script expansions.  Use a function instead.
+          *)
+         failwithf "%a: cannot use goal call ‘%s’ in shell expansion"
+           Ast.string_loc loc name
+
+      | EFuncDefn (loc, func) ->
+         expr_to_shell_string env (call_function env loc name args func)
+
+      | _ ->
+         failwithf "%a: cannot call ‘%s’ which is not a function"
+           Ast.string_loc loc name
+     )
 
-  (* Tactics expand to the first parameter. *)
-  | ETacticCtor (loc, _, []) -> Filename.quote ""
-  | ETacticCtor (loc, _, (arg :: _)) -> expr_to_shell_string env arg
+  (* Predicates expand to the first parameter. *)
+  | EPredCtor (loc, _, []) -> Filename.quote ""
+  | EPredCtor (loc, _, (arg :: _)) -> expr_to_shell_string env arg
 
   | EGoalDefn (loc, _) ->
      failwithf "%a: cannot use goal in shell expansion"
        Ast.string_loc loc
 
-  | ETacticDefn (loc, _) ->
-     failwithf "%a: cannot use tactic in shell expansion"
+  | EFuncDefn (loc, _) ->
+     failwithf "%a: cannot use function in shell expansion"
        Ast.string_loc loc
 
-let rec evaluate_goal_arg env = function
+  | EPredDefn (loc, _) ->
+     failwithf "%a: cannot use predicate in shell expansion"
+       Ast.string_loc loc
+
+and run_code env loc code =
+  let code = prepare_code env loc code in
+  Sys.command code
+
+and run_code_to_string env loc code =
+  let code = prepare_code env loc code in
+  let chan = Unix.open_process_in code in
+  let b = Buffer.create 1024 in
+  (try
+     while true do
+       Buffer.add_string b (input_line chan);
+       Buffer.add_char b '\n'
+     done
+   with End_of_file -> ());
+  let st = Unix.close_process_in chan in
+  let i =
+    match st with
+    | Unix.WEXITED i -> i
+    | Unix.WSIGNALED i ->
+       failwithf "%a: killed by signal %d" Ast.string_loc loc i
+    | Unix.WSTOPPED i ->
+       failwithf "%a: stopped by signal %d" Ast.string_loc loc i in
+  i, Buffer.contents b
+
+and run_code_to_string_list env loc code =
+  let code = prepare_code env loc code in
+  let chan = Unix.open_process_in code in
+  let lines = ref [] in
+  (try while true do lines := input_line chan :: !lines done
+   with End_of_file -> ());
+  let st = Unix.close_process_in chan in
+  let i =
+    match st with
+    | Unix.WEXITED i -> i
+    | Unix.WSIGNALED i ->
+       failwithf "%a: killed by signal %d" Ast.string_loc loc i
+    | Unix.WSTOPPED i ->
+       failwithf "%a: stopped by signal %d" Ast.string_loc loc i in
+  let lines = List.rev !lines in
+  i, lines
+
+and prepare_code env loc (code, quiet) =
+  let quiet = if Cmdline.debug_flag () then false else quiet in
+  let code = to_shell_script env loc code in
+  "source " ^ Filename.quote Cmdline.prelude_sh_file ^ "\n" ^
+  "set -e\n" ^
+  (if not (Cmdline.silent ()) && not quiet then "set -x\n" else "") ^
+  "\n" ^
+  code
+
+and evaluate_goal_arg env = function
   | Ast.EVar (loc, name) ->
      let expr = Ast.getvar env loc name in
      evaluate_goal_arg env expr
@@ -116,16 +206,105 @@ let rec evaluate_goal_arg env = function
   | EList (loc, exprs) ->
      Ast.EList (loc, List.map (evaluate_goal_arg env) exprs)
 
-  | ETacticCtor (loc, name, exprs) ->
-     Ast.ETacticCtor (loc, name, List.map (evaluate_goal_arg env) exprs)
+  | EPredCtor (loc, name, exprs) ->
+     Ast.EPredCtor (loc, name, List.map (evaluate_goal_arg env) exprs)
 
-  | ECallGoal (loc, name, _) ->
-     (* Goals don't return anything so they cannot be used in
-      * goal args.  Use a function instead.
-      *)
-     failwithf "%a: cannot use goal ‘%s’ in goal argument"
-       Ast.string_loc loc name
+  | ECall (loc, name, args) ->
+     let expr = Ast.getvar env loc name in
+     (match expr with
+      | EGoalDefn _ ->
+         (* Goals don't return anything so they cannot be used in
+          * goal args.  Use a function instead.
+          *)
+         failwithf "%a: cannot use goal call ‘%s’ in goal argument"
+           Ast.string_loc loc name
+
+      | EFuncDefn (loc, func) ->
+         call_function env loc name args func
+
+      | _ ->
+         failwithf "%a: cannot call ‘%s’ which is not a function"
+           Ast.string_loc loc name
+     )
 
   | EConstant _
   | EGoalDefn _
-  | ETacticDefn _ as e -> e
+  | EFuncDefn _
+  | EPredDefn _ as e -> e
+
+(* Functions are only called from goal args or when substituting
+ * into a shell script or constant expression (this may change if we
+ * implement ‘:=’ assignment for variables).  This evaluates a
+ * function by running the associated shell script and parsing
+ * the output as an expression, string or list of strings.
+ *)
+and call_function env loc name args (params, returning, pure, code) =
+  (* This is used to print the function in debug and error messages only. *)
+  let debug_func =
+    sprintf "%s (%s) returning %s" name
+      (String.concat ", " (List.map (Ast.string_expr ()) args))
+      (match returning with RetExpr -> "expression"
+                          | RetString -> "string"
+                          | RetStrings -> "strings") in
+  Cmdline.debug "%a: running function %s" Ast.string_loc loc debug_func;
+
+  (* Evaluate function args.  Must be done before updating the environment. *)
+  let args = List.map (evaluate_goal_arg env) args in
+
+  (* Create a new environment which maps the parameter names to
+   * the args.
+   *)
+  let env =
+    let params =
+      try List.combine params args
+      with Invalid_argument _ ->
+        failwithf "%a: calling function %s with wrong number of arguments, expecting %d args but got %d args"
+          Ast.string_loc loc debug_func
+          (List.length params) (List.length args) in
+    List.fold_left (fun env (k, v) -> Ast.Env.add k v env) env params in
+
+  if pure then call_function_pure env loc name returning code
+  else call_function_really env loc name returning code
+
+and call_function_really env loc name returning code =
+  match returning with
+  | RetExpr ->
+     let r, b = run_code_to_string env loc code in
+     if r <> 0 then
+       failwithf "function ‘%s’ failed with exit code %d" name r;
+     Parse.parse_expr (sprintf "function:%s" name) b
+
+  | RetString ->
+     let r, b = run_code_to_string env loc code in
+     if r <> 0 then
+       failwithf "function ‘%s’ failed with exit code %d" name r;
+     (* Remove a single trailing \n if present. *)
+     let b =
+       let len = String.length b in
+       if len > 0 && b.[len-1] = '\n' then String.sub b 0 (len-1) else b in
+     Ast.EConstant (loc, Ast.CString b)
+
+  | RetStrings ->
+     let r, lines = run_code_to_string_list env loc code in
+     let strs = List.map (fun s -> Ast.EConstant (loc, Ast.CString s)) lines in
+     EList (loc, strs)
+
+(* For pure functions, check if the function can be matched to
+ * a previously memoized result, but don't fail if this goes wrong.
+ *)
+and call_function_pure env loc name returning code =
+  let code_key =
+    try Some (to_shell_script env loc (fst code))
+    with Failure _ -> None in
+  match code_key with
+  | None -> call_function_really env loc name returning code
+  | Some code_key ->
+     let r =
+       try Some (Hashtbl.find pure_cache code_key)
+       with Not_found -> None in
+     match r with
+     | Some expr -> expr
+     | None ->
+        let expr = call_function_really env loc name returning code in
+        Hashtbl.add pure_cache code_key expr;
+        expr