LiftToDefs

Is lifting performed on erased terms?

Lift out function prefix and all arguments from application

pre.f(arg1, ..., argN) becomes

val x0 = pre val x1 = arg1 ... val xN = argN x0.f(x1, ..., xN)

But leave pure expressions alone.

Lift arguments that are not-idempotent into ValDefs in buffer defs and replace by the idents of so created ValDefs.

Lift out common part of lhs tree taking part in an operator assignment such as

lhs += expr

Lift prefix pre of an application pre.f(...) to

val x0 = pre x0.f(...)

unless pre is idempotent.