Change package-exists to return section/description

[hcoop/domtool2.git] / src / plugins / apt.sml

diff --git a/src/plugins/apt.sml b/src/plugins/apt.sml
index e97ec82..a7ae93a 100644 (file)
--- a/src/plugins/apt.sml
+++ b/src/plugins/apt.sml
@@ -26,27 +26,32 @@ fun validName s = CharVector.all (fn ch => Char.isAlphaNum ch orelse ch = #"_" o
 (* Copyed from the portal, doesn't exactly go out this in the most
    direct way, or does it? *)
 
-fun exists name =
-    validName name andalso let
-       val proc = Unix.execute ("/usr/bin/apt-cache", ["show", name])
-       val inf = Unix.textInstreamOf proc
-
-       val _ = TextIO.inputLine inf (* in every let* lies an imperative program in disguise *)
-
-       fun loop _ =
-           case TextIO.inputLine inf of
-               NONE => false
-             | SOME line =>
-               if size line >= 9 andalso String.substring (line, 0, 9) = "Section: " then
-                   true
-               else if size line >= 13 andalso String.substring (line, 0, 13) = "Description: " then
-                   false
-               else
-                   loop ()
-    in
-       loop ()
-       before ignore (Unix.reap proc)
-    end
+fun info name =
+    if not (validName name) then
+       NONE
+    else
+       let
+           val proc = Unix.execute ("/usr/bin/apt-cache", ["show", name])
+           val inf = Unix.textInstreamOf proc
+                     
+           val _ = TextIO.inputLine inf (* in every let* lies an imperative program in disguise *)
+                   
+           fun loop (section, descr) =
+               case TextIO.inputLine inf of
+                   NONE => (section, descr)
+                 | SOME line =>
+                   if size line >= 9 andalso String.substring (line, 0, 9) = "Section: " then
+                       loop (SOME (String.substring (line, 9, size line - 10)), descr)
+                   else if size line >= 13 andalso String.substring (line, 0, 13) = "Description: " then
+                       loop (section, SOME (String.substring (line, 13, size line - 14)))
+                   else
+                       loop (section, descr)
+       in
+           (case loop (NONE, NONE) of
+                (SOME section, SOME descr) => SOME {section = section, description = descr}
+              | _ => NONE)
+           before ignore (Unix.reap proc)
+       end
                           
 fun installed name =
     validName name