v0.2.0

Breaking changes

• Formal arguments of partial(..f, ...) no longer record the original
  default values of ..f (since a default-value expression may reference an
  argument that is fixed, and therefore dropped, by partial()).
  Nevertheless, any default values of ..f not overridden by partial()
  remain in force when the function partial(..f, ...) is called.

• partial(..f, ...) can still fix arguments that match the ... argument of
  ..f (if present), but only when such arguments are specified by name.

Bug fix

• Default argument values of a composite function are now evaluated in the
  evaluation environment of the initial function. Essentially, a call like
  compose(f, g)(x, y, ...) is now equivalent to a call like
  (function(...) g(f(...)))(x, y, ...). (Previously, the initial
  function was called with a complete set of formal arguments, which in cases
  where formal arguments are mutated or mutually referenced (e.g., in the
  formals of base::objects()), could lead the initial function to wrongly
  determine the "missingness" of an argument or wrongly evaluate an argument's
  default value.) As before, the signature of compose(f, ...) inherits the
  signature of f.