The |> operator is a reverse function operator with low binding strength
to replace lib.pipe. Implements RFC 148, see the RFC text for more
details. Closes#438.
Change-Id: I21df66e8014e0d4dd9753dd038560a2b0b7fd805
Currently, the parser relies on the global experimental feature flags.
In order to properly test conditional language features, we instead need
to pass it around in the parser::State.
This means that the parser cannot cache the result of isEnabled anymore,
which wouldn't necessarily hurt performance if the function didn't
perform a linear search on the list of enabled features on every single
call. While we could simply evaluate once at the start of parsing and
cache the result in the parser state, the more sustainable solution
would be to fix `isEnabled` such that all callers may profit from the
performance improvement.
Change-Id: Ic9b9c5d882b6270e1114988b63e6064d36c25cf2
