Futures with an error but no callback no longer raise.

This was done as a safety measure against futures which may be
accidentally discarded when they have an exception leading the exception
being silently forgotten. Unfortunately we will need to come up with
some other solution.

1 files changed, 11 insertions, 6 deletions

diff --git a/lib/pure/asyncdispatch.nim b/lib/pure/asyncdispatch.nim
index 6d9e605f1..6292bfc12 100644
--- a/lib/pure/asyncdispatch.nim
+++ b/lib/pure/asyncdispatch.nim
@@ -26,12 +26,12 @@ export TPort
 ## **Note:** This module is still largely experimental.
 
 
-# TODO: Discarded void PFutures need to checked for exception.
+# TODO: Discarded void PFutures need to be checked for exception.
 # TODO: ``except`` statement (without `try`) does not work.
 # TODO: Multiple exception names in a ``except`` don't work.
 # TODO: The effect system (raises: []) has trouble with my try transformation.
 # TODO: Can't await in a 'except' body
-
+# TODO: getCurrentException(Msg) don't work
 
 # -- Futures
 
@@ -77,7 +77,8 @@ proc fail*[T](future: PFuture[T], error: ref EBase) =
     # This is to prevent exceptions from being silently ignored when a future
     # is discarded.
     # TODO: This may turn out to be a bad idea.
-    raise error
+    # Turns out this is a bad idea.
+    #raise error
 
 proc `callback=`*(future: PFutureBase, cb: proc () {.closure,gcsafe.}) =
   ## Sets the callback proc to be called when the future completes.
@@ -775,14 +776,16 @@ proc accept*(socket: TAsyncFD): PFuture[TAsyncFD] =
 
 # -- Await Macro
 
-template createCb*(retFutureSym, iteratorNameSym: expr): stmt {.immediate.} =
+template createCb*(retFutureSym, iteratorNameSym,
+                   name: expr): stmt {.immediate.} =
   var nameIterVar = iteratorNameSym
   proc cb {.closure,gcsafe.} =
     try:
       if not nameIterVar.finished:
         var next = nameIterVar()
         if next == nil:
-          assert retFutureSym.finished, "Async procedure's return Future was not finished."
+          assert retFutureSym.finished, "Async procedure's (" &
+                 name & ") return Future was not finished."
         else:
           next.callback = cb
     except:
@@ -987,7 +990,8 @@ macro async*(prc: stmt): stmt {.immediate.} =
 
   # -> createCb(retFuture)
   var cbName = newIdentNode("cb")
-  var procCb = newCall("createCb", retFutureSym, iteratorNameSym)
+  var procCb = newCall("createCb", retFutureSym, iteratorNameSym,
+                       newStrLitNode(prc[0].getName))
   outerProcBody.add procCb
 
   # -> return retFuture
@@ -1010,6 +1014,7 @@ macro async*(prc: stmt): stmt {.immediate.} =
   result[6] = outerProcBody
 
   #echo(treeRepr(result))
+  #if prc[0].getName == "routeReq":
   #echo(toStrLit(result))
 
 proc recvLine*(socket: TAsyncFD): PFuture[string] {.async.} =