X-Git-Url: http://git.annexia.org/?a=blobdiff_plain;f=src%2Feval.ml;h=59f4ca4dc87b4b8f299c14b1e9a2add29b04f4da;hb=109185686ffdc00520eba2b4c3a92f10a111fb60;hp=a0ed8345a9809936f4be5b3c57aa62f022b92004;hpb=976bb1b35d77f3058df3c25c1e2a4767147d606b;p=goals.git

diff --git a/src/eval.ml b/src/eval.ml
index a0ed834..59f4ca4 100644
--- a/src/eval.ml
+++ b/src/eval.ml
@@ -21,6 +21,8 @@ open Printf
 
 open Utils
 
+let pure_cache = Hashtbl.create 13
+
 let rec to_constant env = function
   | Ast.EConstant (loc, c) -> c
 
@@ -142,6 +144,56 @@ and expr_to_shell_string env = function
      failwithf "%a: cannot use tactic 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 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
@@ -183,16 +235,17 @@ and evaluate_goal_arg env = function
 (* 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 substituting
- * the output into an EList.
- *
- * XXX In future allow functions to be annotated with a return type.
+ * 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, code) =
+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)" name
-      (String.concat ", " (List.map (Ast.string_expr ()) args)) in
+    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. *)
@@ -210,27 +263,44 @@ and call_function env loc name args (params, code) =
           (List.length params) (List.length args) in
     List.fold_left (fun env (k, v) -> Ast.Env.add k v env) env params in
 
-  (* Run the code. *)
-  let code = to_shell_script env loc code in
-  let code = "set -e\n" (*^ "set -x\n"*) ^ "\n" ^ 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 lines = List.rev !lines in
-  let st = Unix.close_process_in chan in
-  (match st with
-  | Unix.WEXITED 0 -> ()
-  | Unix.WEXITED i ->
-     eprintf "*** function ‘%s’ failed with exit code %d\n" name i
-  | Unix.WSIGNALED i ->
-     eprintf "*** function ‘%s’ killed by signal %d\n" name i
-  | Unix.WSTOPPED i ->
-     eprintf "*** function ‘%s’ stopped by signal %d\n" name i
-  );
-
-  Ast.EList (Ast.noloc,
-             (List.map (fun line ->
-                  Ast.EConstant (Ast.noloc, Ast.CString line))
-                lines))
+  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;
+     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