X-Git-Url: http://git.annexia.org/?a=blobdiff_plain;f=src%2Feval.ml;h=3363eefed5068764589d1486a1cd0f1cd3e282d7;hb=d3356e11d92f09a2bcb9ba145594cf4b0531328f;hp=4496319d3f1c35ad8648f3c05d746620910f1581;hpb=a48b05d35f0646322e8178ff10f8ed7af3e739aa;p=goals.git

diff --git a/src/eval.ml b/src/eval.ml
index 4496319..3363eef 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
 
@@ -142,15 +144,12 @@ and expr_to_shell_string env = function
      failwithf "%a: cannot use tactic in shell expansion"
        Ast.string_loc loc
 
-and run_code ?(quiet = false) env loc code =
-  let code = to_shell_script env loc code in
-  let code =
-    "source " ^ Filename.quote Cmdline.prelude_sh_file ^ "\n" ^
-    "set -e\n" ^
-    (if not quiet then "set -x\n" else "") ^
-    "\n" ^
-    code in
+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
@@ -169,6 +168,32 @@ and run_code ?(quiet = false) env loc code =
        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
@@ -211,13 +236,16 @@ and evaluate_goal_arg env = function
  * 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.
+ * 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. *)
@@ -235,9 +263,48 @@ 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
 
-  let r, b = run_code env loc code in
-  if r <> 0 then (
-    eprintf "*** function ‘%s’ failed with exit code %d\n" name r;
-    exit 1
-  );
-  Parse.parse_expr (sprintf "function:%s" name) b
+  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