[minor] small readability improvements

Summary: Random edits made while reading ZipLib.ml. They're really not interesting, sorry...

Reviewed By: sblackshear

Differential Revision: D7686159

fbshipit-source-id: 19ef1ce

infer/src/base/Config.ml

@@ -2835,15 +2835,14 @@ let specs_library =
   match infer_cache with
   | Some cache_dir when use_jar_cache ->
       let add_spec_lib specs_library filename =
+        let key_dir =
           let basename = Filename.basename filename in
           let key = basename ^ Utils.string_crc_hex32 filename in
-        let key_dir = cache_dir ^/ key in
+          cache_dir ^/ key
+        in
         let extract_specs dest_dir filename =
-          if Filename.check_suffix filename ".jar" then
+          if Filename.check_suffix filename ".jar" then (
-            match Unix.mkdir dest_dir ~perm:0o700 with
+            (try Unix.mkdir dest_dir ~perm:0o700 with Unix.Unix_error _ -> ()) ;
-            | exception Unix.Unix_error _ ->
-                ()
-            | () ->
             let zip_channel = Zip.open_in filename in
             let entries = Zip.entries zip_channel in
             let extract_entry (entry: Zip.entry) =
@@ -2852,7 +2851,7 @@ let specs_library =
                 Zip.copy_entry_to_file zip_channel entry dest_file
             in
             List.iter ~f:extract_entry entries ;
-                Zip.close_in zip_channel
+            Zip.close_in zip_channel )
         in
         extract_specs key_dir filename ; key_dir :: specs_library
       in

infer/src/base/ZipLib.ml

@@ -31,8 +31,8 @@ let load_from_cache serializer zip_path cache_dir zip_library =
     DB.filename_from_string to_path
   in
   match deserialize (extract absolute_path) with
-  | Some data ->
+  | Some _ as data ->
-      Some data
+      data
   | None ->
       None
   | exception Caml.Not_found ->
@@ -69,26 +69,27 @@ let zip_libraries =
        {models; zip_filename; zip_channel= lazy (Zip.open_in zip_filename)}
      in
      let zip_libs =
-       if Config.use_jar_cache && Config.infer_cache <> None then []
+       if Config.use_jar_cache && Option.is_some Config.infer_cache then []
        else
-         (* Order matters, jar files should appear in the order in which they should be searched for
+         let load_zip fname =
-           specs files. Config.specs_library is in reverse order of appearance on command line. *)
-         let add_zip zip_libs fname =
            if Filename.check_suffix fname ".jar" then
              (* fname is a zip of specs *)
-             mk_zip_lib false fname :: zip_libs
+             Some (mk_zip_lib false fname)
            else (* fname is a dir of specs *)
-             zip_libs
+             None
          in
-         List.fold ~f:add_zip ~init:[] Config.specs_library
+         (* Order matters: jar files should appear in the order in which they should be searched for
+            specs files. [Config.specs_library] is in reverse order of appearance on the command
+            line. *)
+         List.rev_filter_map Config.specs_library ~f:load_zip
      in
      if Config.biabduction && not Config.models_mode && Sys.file_exists Config.models_jar = `Yes
      then mk_zip_lib true Config.models_jar :: zip_libs
      else zip_libs)
 
 
-(* Search path in the list of zip libraries and use a cache directory to save already
+(** Search path in the list of zip libraries and use a cache directory to save already deserialized
-   deserialized data *)
+    data *)
 let load serializer path =
   let rec loop = function
     | [] ->