X-Git-Url: http://git.annexia.org/?a=blobdiff_plain;ds=sidebyside;f=src%2Feval.ml;h=daa13b66bde938c75545cb7fec9cc7c7f8f87a4b;hb=a925b902c8f87f9dfc7e39f6c31426e7527cefee;hp=b8dbe54661be8491f2ae975701aae4d7b92b36ea;hpb=c46c3a5c7793753f2f15c1655517f3f9b8fee644;p=goals.git

diff --git a/src/eval.ml b/src/eval.ml
index b8dbe54..daa13b6 100644
--- a/src/eval.ml
+++ b/src/eval.ml
@@ -27,31 +27,19 @@ and evaluate_target env = function
 
   (* Call a goal. *)
   | Ast.ECall (loc, name, args) ->
-     let expr =
-       try Ast.Env.find name env
-       with Not_found ->
-         failwithf "%a: goal ‘%s’ not found" Ast.string_loc loc name in
-     let goal =
-       match expr with
-       | Ast.EGoal (loc, goal) -> goal
-       | _ ->
-          failwithf "%a: tried to call ‘%s’ which is not a goal"
-            Ast.string_loc loc name in
-     run_goal loc env name args goal
+     let goal = Ast.getgoal env loc name in
+     run_goal env loc name args goal
 
   | Ast.ETactic (loc, name, args) ->
-     (* All parameters of tactics must be simple expressions (strings,
-      * in future booleans, numbers, etc).
+     (* All parameters of tactics must be simple constant expressions
+      * (strings, in future booleans, numbers, etc).
       *)
-     let args = List.map (simplify env) args in
-     run_goal_for_tactic loc env name args
+     let args = List.map (Ast.to_constant env) args in
+     run_tactic env loc name args
 
   (* Look up the variable and substitute it. *)
   | Ast.EVar (loc, name) ->
-     let expr =
-       try Ast.Env.find name env
-       with Not_found ->
-         failwithf "%a: variable ‘%s’ not found" Ast.string_loc loc name in
+     let expr = Ast.getvar env loc name in
      evaluate_target env expr
 
   (* Lists are inlined when found as a target. *)
@@ -60,146 +48,237 @@ and evaluate_target env = function
 
   (* A string (with or without substitutions) implies *file(filename). *)
   | Ast.ESubsts (loc, str) ->
-     let str = substitute loc env str in
-     run_goal_for_tactic loc env "file" [Ast.CString str]
+     let str = Ast.substitute env loc str in
+     run_tactic env loc "file" [Ast.CString str]
 
   | Ast.EConstant (loc, c) ->
-     run_goal_for_tactic loc env "file" [c]
+     run_tactic env loc "file" [c]
 
-(* Find the goal which matches the given tactic and run it.
- * Params is a list of constants.
- *)
-and run_goal_for_tactic loc env tactic const_args =
-  (* Search across all goals for a matching tactic. *)
-  let goals =
-    let env = Ast.Env.bindings env in
-    filter_map
-      (function (name, Ast.EGoal (loc, goal)) -> Some (name, goal) | _ -> None)
-      env in
-  let name, goal =
-    (* If there are multiple goals matching, this must choose
-     * the most recently defined (XXX).
-     *)
-    try
-      List.find
-        (fun (_, (_, patterns, _, _)) ->
-          List.exists (matching_pattern loc env tactic const_args) patterns)
-        goals
-    with
-      Not_found ->
-        failwithf "%a: don't know how to build %s %s"
-          Ast.string_loc loc
-          tactic
-          (String.concat ", "
-             (List.map (function Ast.CString s -> s) const_args)) in
-
-  let args = [] (* XXX calculate free variables *) in
-  run_goal loc env name args goal
-
-(* XXX This only does exact matches at the moment. *)
-and matching_pattern loc env tactic const_args = function
-  | Ast.PTactic (loc, constructor, params)
-       when tactic = constructor &&
-            List.length const_args = List.length params ->
-     (* Try to simplify the parameters of this pattern down
-      * to constants, but don't fail here if we can't do this.
-      *)
-     (try
-        let params = List.map (substitute loc env) params in
-        let params = List.map (fun s -> Ast.CString s) params in
-        const_args = params
-      with Failure _ -> false
-     )
-
-  | Ast.PTactic _ -> false
-
-  | Ast.PVar (loc, name) -> assert false
-(*
-  NOT IMPLEMENTED - we need variables to contain constructors!
-     (try
-        let expr = Ast.StringMap.find name env in
-        let expr = simplify env expr in
-      with Not_found -> false
-     )
-*)
-
-(* Run a named goal. *)
-and run_goal loc env name args (params, patterns, deps, code) =
-  (* Substitute the args for the parameters in the environment. *)
-  let params =
-    try List.combine params args
-    with Invalid_argument _ ->
-      failwithf "%a: calling goal ‘%s’ with wrong number of arguments"
-        Ast.string_loc loc name in
+(* Run a goal by name. *)
+and run_goal env loc name args (params, patterns, deps, code) =
+  (* Create a new environment which maps the parameter names to
+   * the args.
+   *)
   let env =
-    List.fold_left (fun env (k, v) -> Ast.Env.add k v env)
-      env params in
+    let params =
+      try List.combine params args
+      with Invalid_argument _ ->
+        failwithf "%a: calling goal ‘%s’ with wrong number of arguments"
+          Ast.string_loc loc name in
+    List.fold_left (fun env (k, v) -> Ast.Env.add k v env) env params in
 
-  (* Evaluate the dependencies first. *)
+  (* Check all dependencies have been updated. *)
   evaluate_targets env deps;
 
-  (* Check if any target needs to be updated. *)
-  (* XXX *)
+  (* Check if any target (ie. pattern) needs to be rebuilt. *)
+  let rebuild = List.exists (needs_rebuild env loc deps) patterns in
 
-  (* Run the code (if any). *)
-  (match code with
-   | None -> ()
-   | Some code ->
-      let code = substitute loc env code in
-      Printf.printf "running : %s\n" code
-  );
+  if rebuild then (
+    (* Run the code (if any). *)
+    (match code with
+     | None -> ()
+     | Some code ->
+        (* Add some standard variables to the environment. *)
+        let expr_of_substs s = Ast.ESubsts (Ast.noloc, s) in
+        let expr_of_pattern = function
+          | Ast.PTactic (loc, tactic, targs) ->
+             Ast.ETactic (loc, tactic, List.map expr_of_substs targs)
+          | Ast.PVar (loc, name) ->
+             Ast.EVar (loc, name)
+        in
+        let pexprs = List.map expr_of_pattern patterns in
+        let env = Ast.Env.add "@" (Ast.EList (Ast.noloc, pexprs)) env in
+        let env = Ast.Env.add "<" (Ast.EList (Ast.noloc, deps)) env in
+        let env =
+          match deps with
+          | [] -> env
+          | d :: _ -> Ast.Env.add "^" d env in
+        let code = Ast.to_shell_script env loc code in
+        Printf.printf "running : %s\n" code
+    );
 
-  (* Check all targets were updated (else it's an error). *)
-  (* XXX *)
+    (* Check all targets were updated (else it's an error). *)
+    let pattern_still_needs_rebuild =
+      try Some (List.find (needs_rebuild env loc deps) patterns)
+      with Not_found -> None in
+    match pattern_still_needs_rebuild with
+    | None -> ()
+    | Some pattern ->
+       failwithf "%a: goal ‘%s’ ran successfully but it did not rebuild %a"
+         Ast.string_loc loc
+         name
+         Ast.string_pattern pattern
+  )
+
+(* Return whether the target (pattern) needs to be rebuilt. *)
+and needs_rebuild env loc deps pattern =
+  match pattern with
+  | Ast.PTactic (loc, tactic, targs) ->
+     (* Resolve the targs down to constants. *)
+     let targs = List.map ((* XXX Ast.to_shell_script *)
+                            Ast.substitute env loc) targs in
+     (* XXX Look up the tactic.
+      * We would do that, but for now hard code the *file tactic. XXX
+      *)
+     assert (tactic = "file");
+     assert (List.length targs = 1);
+     let targ = List.hd targs in
+     not (Sys.file_exists targ)
+  | Ast.PVar _ -> assert false (* XXX not implemented *)
 
-(* Take any expression and simplify it down to a constant.
- * If the expression cannot be simplified then this throws
- * an error.
+(* Find the goal which matches the given tactic and run it.
+ * cargs is a list of parameters (all constants).
  *)
-and simplify env = function
-  | Ast.EConstant (loc, c) -> c
+and run_tactic env loc tactic cargs =
+  (* Find all goals in the environment.  Returns a list of (name, goal). *)
+  let goals =
+    let env = Ast.Env.bindings env in
+    filter_map
+      (function
+       | name, Ast.EGoal (loc, goal) -> Some (name, goal)
+       | _ -> None) env in
 
-  | Ast.EVar (loc, name) ->
-     let expr =
-       try Ast.Env.find name env
-       with Not_found ->
-         failwithf "%a: variable ‘%s’ not found" Ast.string_loc loc name in
-     simplify env expr
+  (* Find all patterns.  Returns a list of (pattern, name, goal). *)
+  let patterns : (Ast.pattern * Ast.id * Ast.goal) list =
+    List.flatten
+      (List.map (fun (name, ((_, patterns, _, _) as goal)) ->
+           List.map (fun pattern -> (pattern, name, goal)) patterns) goals) in
 
-  | Ast.ESubsts (loc, str) ->
-     Ast.CString (substitute loc env str)
+  (* Find any patterns (ie. tactics) which match the one we
+   * are searching for.  This returns a binding for the goal args,
+   * so we end up with a list of (pattern, name, goal, args).
+   *)
+  let patterns : (Ast.pattern * Ast.id * Ast.goal * Ast.expr list) list =
+    filter_map (
+      fun (pattern, name, ((params, _, _, _) as goal)) ->
+        match matching_pattern env loc tactic cargs pattern params with
+        | None -> None
+        | Some args -> Some (pattern, name, goal, args)
+    ) patterns in
+
+  match patterns with
+  | [_, name, goal, args] ->
+     run_goal env loc name args goal
+
+  | [] ->
+     (* There's no matching goal, but we don't need one if
+      * the tactic doesn't need to be rebuilt.
+      *)
+     let targs = List.map (function Ast.CString s -> [Ast.SString s]) cargs in
+     let p = Ast.PTactic (loc, tactic, targs) in
+     if needs_rebuild env loc [] p then (
+       let t = Ast.ETactic (loc, tactic,
+                            List.map (fun c -> Ast.EConstant (loc, c))
+                              cargs) in
+       failwithf "%a: don't know how to build %a"
+         Ast.string_loc loc Ast.string_expr t
+     )
 
-  | Ast.EList (loc, _) ->
-     failwithf "%a: list found where constant expression expected"
-       Ast.string_loc loc
+  | _ ->
+     (* If there are multiple matching goals, then assuming the goals
+      * are different we must pick the one which was defined last in
+      * the file.  However we don't do that right now. XXX
+      *)
+     assert false (* TODO! *)
 
-  | Ast.ECall (loc, name, _) ->
-     failwithf "%a: cannot use goal ‘%s’ in constant expression"
-       Ast.string_loc loc name
+(* Test if pattern matches *tactic(cargs).  If it does
+ * then we return Some args where args is the arguments that must
+ * be passed to the matching goal.  The params parameter is
+ * the names of the parameters of that goal.
+ *)
+and matching_pattern env loc tactic cargs pattern params =
+  match pattern with
+  | Ast.PVar (loc, name) -> assert false (* TODO! *)
+  | Ast.PTactic (loc, ttactic, targs)
+       when tactic <> ttactic ||
+            List.length cargs <> List.length targs ->
+     None (* Can't possibly match if tactic name or #args is different. *)
+  | Ast.PTactic (loc, ttactic, targs) ->
+     (* Do the args match with a possible params binding? *)
+     try Some (matching_params env loc params targs cargs)
+     with Not_found -> None
 
-  | Ast.ETactic (loc, name, _) ->
-     failwithf "%a: cannot use tactic ‘*%s’ in constant expression"
-       Ast.string_loc loc name
+(* Return a possible binding.  For example the goal is:
+ *   goal compile (name) = "%name.o": "%name.c" {}
+ * which means that params = ["name"] and targs = ["%name.o"].
+ *
+ * If we are called with cargs = ["file1.o"], we would
+ * return ["file1"].
+ *
+ * On non-matching this raises Not_found.
+ *)
+and matching_params env loc params targs cargs =
+  (* This is going to record the resulting binding. *)
+  let res = ref Ast.Env.empty in
+  List.iter2 (matching_param env loc params res) targs cargs;
 
-  | Ast.EGoal (loc, _) ->
-     failwithf "%a: cannot use goal in constant expression"
-       Ast.string_loc loc
+  (* Rearrange the result into goal parameter order.  Also this
+   * checks that every parameter got a binding.
+   *)
+  let res = !res in
+  List.map (
+    (* Allow the Not_found exception to escape if no binding for this param. *)
+    fun param -> Ast.Env.find param res
+  ) params
 
-(* Take a substitution list and try to turn it into a simple
- * string by evaluating every variable.  If not possible this
- * throws an error.  Returns a string.
+(* If targ = "%name.o" and carg = "file.o" then this would set
+ * name => "file" in !res.  If they don't match, raises Not_found.
  *)
-and substitute loc env substs =
-  let b = Buffer.create 13 in
-  List.iter (
-    function
-    | Ast.SString s -> Buffer.add_string b s
-    | Ast.SVar name ->
-       let expr =
-         try Ast.Env.find name env
-         with Not_found ->
-           failwithf "%a: variable ‘%s’ not found" Ast.string_loc loc name in
-       match simplify env expr with
-       | Ast.CString s -> Buffer.add_string b s
-  ) substs;
-  Buffer.contents b
+and matching_param env loc params res targ carg =
+  match carg with
+  | Ast.CString carg ->
+     (* Substitute any non parameters in targ from the environment. *)
+     let targ =
+       List.map (
+         function
+         | Ast.SString _ as s -> s
+         | Ast.SVar name ->
+            if not (List.mem name params) then (
+              try
+                let expr = Ast.getvar env loc name in
+                match Ast.to_constant env expr with
+                | Ast.CString s -> Ast.SString s
+              with Failure _ -> raise Not_found
+            )
+            else
+              Ast.SVar name
+       ) targ in
+
+     (* Do the actual pattern matching.  Any remaining SVar elements
+      * must refer to goal parameters.
+      *)
+     let carg = ref carg in
+     let rec loop = function
+       | [] ->
+          (* End of targ, we must have matched all of carg. *)
+          if !carg <> "" then raise Not_found
+       | Ast.SString s :: rest ->
+          (* Does this match the first part of !carg? *)
+          let clen = String.length !carg in
+          let slen = String.length s in
+          if slen > clen || s <> String.sub !carg 0 slen then
+            raise Not_found;
+          (* Yes, so continue after the matching prefix. *)
+          carg := String.sub !carg slen (clen-slen);
+          loop rest
+       | Ast.SVar name :: Ast.SString s :: rest ->
+          (* This is a goal parameter.  Find s later in !carg. *)
+          let i = string_find !carg s in
+          if i = -1 then raise Not_found;
+          (* Set the binding in !res. *)
+          let r = Ast.EConstant (Ast.noloc,
+                                 Ast.CString (String.sub !carg 0 i)) in
+          res := Ast.Env.add name r !res;
+          (* Continue after the match. *)
+          let skip = i + String.length s in
+          carg := String.sub !carg skip (String.length !carg - skip);
+          loop rest
+       | Ast.SVar name :: [] ->
+          (* Matches the whole remainder of the string. *)
+          let r = Ast.EConstant (Ast.noloc, Ast.CString !carg) in
+          res := Ast.Env.add name r !res
+       | Ast.SVar x :: Ast.SVar y :: _ ->
+          (* TODO! We cannot match a target like "%x%y". *)
+          assert false
+     in
+     loop targ