In Scala 2.10, when macros were first introduced, our public API exposed two low-level methods: Context.resetLocalAttrs
and
Context.resetAllAttrs
. While these methods wouldn't be needed at all if our internal implementation of the macro API were more advanced,
at our past level of technology we needed them (and we still do) to deal with possible inconsistencies in partially synthetic trees.
Without going into details, experience has shown that resetLocalAttrs
can deal with a majority of possible inconsistencies
having a mild chance of corrupting trees as a side-effect of its operation, whereas resetAllAttrs
can deal with some additional inconsistencies,
but it's almost always guaranteed to corrupt trees. Go through our Macrology 201
tutorial to learn more about this topic.
Anyway, based on what we've learned about resetAttrs methods, in Scala 2.11.0 we removed resetAllAttrs
and renamed resetLocalAttrs
to untypecheck
, branding resetLocalAttrs
as the one and only public way of fixing inconsistencies in trees.
When doing that, we expected that resetLocalAttrs
should be enough for virtually everyone who previously used resetAllAttrs
.
Unfortunately, that ended up being not the case and due to binary compatibility constraints we can't just reintroduce resetAllAttrs
in 2.11.x
(or even in 2.12.x, for that matter). So here we go, reinstating resetAllAttrs
in a separate library for the cases when it's really necessary. Let's hope the necessity for resetAllAttrs
won't last for long.
In your SBT build you need to write a one-liner:
libraryDependencies += "org.scalamacros" %% "resetallattrs" % "1.0.0"
Then in your macros you write another one-liner, and that enables you to use resetAllAttrs
like in the good old days.
Beware, all usual caveats apply. Please try untypecheck
first, and only then reach for resetAllAttrs
.
def impl(c: Context)(...) = {
...
import org.scalamacros.resetallattrs._
c.resetAllAttrs(...)
...
}