Export a default capability generator

src/syndicate/capabilities.nim

@@ -3,6 +3,7 @@
 
 import preserves
 import ./protocols/sturdy, ./private/hmacs
+from ./actors import Ref
 
 export `$`
 
@@ -13,6 +14,10 @@ proc mint*[T](key: openarray[byte]; oid: T; E = void): SturdyRef[E] =
   var oidPr = toPreserve(oid, E)
   SturdyRef[E](oid: oidPr, sig: hmacSha256(key, encode(oidPr), key.len))
 
+proc mint*(): SturdyRef[Ref] =
+  var key: array[16, byte]
+  cast[SturdyRef[Ref]](mint(key, "syndicate", Ref))
+
 proc attenuate*[T](r: SturdyRef[T]; caveats: Attenuation): SturdyRef[T] =
   result = SturdyRef[T](
     oid: r.oid,

tests/chat.nim

@@ -5,17 +5,13 @@ import std/[asyncdispatch, os]
 import preserves, syndicate, syndicate/capabilities
 import syndicate/protocols/simpleChatProtocol
 
-proc mintCap: SturdyRef =
-  var key: array[16, byte]
-  mint(key, "syndicate")
-
 proc unixSocketPath: string =
   result = getEnv("SYNDICATE_SOCK")
   if result == "":
     result = getEnv("XDG_RUNTIME_DIR", "/run/user/1000") / "dataspace"
 
 bootDataspace("main") do (root: Ref; turn: var Turn):
-  connectUnix(turn, unixSocketPath(), mintCap()) do (turn: var Turn; ds: Ref):
+  connectUnix(turn, unixSocketPath(), capabilities.mint()) do (turn: var Turn; ds: Ref):
     var
       username: string
       usernameHandle: Handle

tests/stdio_client.nim

@@ -9,10 +9,6 @@ import syndicate/[actors, capabilities]
 
 randomize()
 
-proc mint(): SturdyRef =
-  var key: array[16, byte]
-  mint(key, "syndicate")
-
 type
   A* {.preservesRecord: "A".} = object
     str*: string
@@ -30,7 +26,7 @@ bootDataspace("x") do (ds: Ref; turn: var Turn):
 
 bootDataspace("y") do (ds: Ref; turn: var Turn):
 
-  connectUnix(turn, "/run/user/1000/dataspace", mint()) do (turn: var Turn; a: Assertion) -> TurnAction:
+  connectUnix(turn, "/run/user/1000/dataspace", capabilities.mint()) do (turn: var Turn; a: Assertion) -> TurnAction:
     let ds = unembed a
 
     discard publish(turn, ds, A(str: "A unix"))