Address review comments; Add documentation; Shared buffering mechanism for input and output streams

faststreams/async_backend.nim

@@ -1,18 +1,29 @@
 const
   faststreams_async_backend {.strdefine.} = "chronos"
 
-when faststreams_async_backend == "chronos":
-  import chronos # import chronos/[asyncfutures2, asyncmacro2]
-  export chronos # export asyncfutures2, asyncmacro2
+type
+  CloseBehavior* = enum
+    waitAsyncClose
+    dontWaitAsyncClose
 
-  template faststreamsAwait*(f: Future): untyped =
+when faststreams_async_backend == "chronos":
+  import
+    chronos
+
+  export
+    chronos
+
+  template fsAwait*(f: Future): untyped =
     await f
 
 elif faststreams_async_backend in ["std", "asyncdispatch"]:
-  import std/[asyncfutures, asyncmacro]
-  export asyncfutures, asyncmacro
+  import
+    std/[asyncfutures, asyncmacro]
+  
+  export
+    asyncfutures, asyncmacro
 
-  template faststreamsAwait*(awaited: Future[T]): untyped =
+  template fsAwait*(awaited: Future[T]): untyped =
     # TODO revisit after https://github.com/nim-lang/Nim/pull/12085/ is merged
     let f = awaited
     yield f
@@ -23,9 +34,15 @@ elif faststreams_async_backend in ["std", "asyncdispatch"]:
 else:
   {.fatal: "Unrecognized network backend: " & faststreams_async_backend.}
 
-template raiseFaststreamsError*(errMsg: string, body: untyped) =
+template fsTranslateErrors*(errMsg: string, body: untyped) =
   try:
     body
-  except CatchableError as err:
-    raise newException(IOError, errMsg, err)
+  except Exception as err:
+    if err[] of Defect:
+      raise (ref Defect)(err)
+    else:
+      raise newException(IOError, errMsg, err)
+
+template noAwait*(expr: untyped): untyped =
+  expr