Add asyncMapBuffer (dart-lang/stream_transform#39)

In one use case for `buffer` the `trigger` depended on the output from
the resulting stream so the handling was awkward and used a manual
StreamController. The intention was to avoid re-entry into a block of
work, and asyncMapBuffer lets us express that intention directly.
6 files changed
tree: 326ab7609be2367247f6f2df6f12de32a6b81cc9
  1. pkgs/