I wondered about this and poked at the internals of ByteString (suitable for ffi) and Text. Turns out Text could allow ffi by changing a single function (newByt

I wondered about this and poked at the internals of ByteString (suitable for ffi) and Text. Turns out Text could allow ffi by changing a single function (newByteArray to newAlignedPinnedByteArray). Presumably creating lots of small strings is a typical use case for Text so losing compacting gc hurts. ByteString on the other hand is more used with binary data and is designed for ffi use.