** Programatic Utilities for Formulas, Expressions, Calls, Assignments and Other R Objects**
These utilities facilitate the programmatic manipulations of formulas, expressions, calls, names, symbols and other R language objects. These objects all share the same structure: a left-hand side (lhs), an operator (op) and right-hand side (rhs). This packages provides methods for accessing and modifying this structures as well as extracting and replacing names and symbols from these objects.
It is easiest to understand through the [#Examples].
base::all.varsexcept all symbols, etc. can be interpolated on data, so that things like
y ~ .can return the correct values.
get.varson lhs of the object
get.varson rhs of the object
Formula terms and operators can be accessed or changed.
form <- y ~ x lhs(form) # y lhs(form) lhs(form) <- quote(t)