pryr (rhymes with pry bar)

pryr provides tools to pry back the surface of R and dig into the details. It has been developed in conjunction with "Advanced R programming" to make it easier to understand what's going on in R.

Install it from CRAN with install.packages("pryr").

Tools

pryr includes tools to:

• Make it easier to understand the internal implementation of:

  • promises: uneval(), is_promise(), promise_info()
  • scoping and environments: where(), rls(), parenv()
  • closures: unenclose()
  • calls and expressions: call_tree()
  • primitive types: typenames()
  • copy-on-modify: address(), track_copy()

• Inspect and understand R's OO systems:

  • Determine which OO system an object belongs to: otype()
  • Determine which OO system a function belongs to: ftype()

• Make it easier to compute on the language:

  • Alternative ways to create functions: make_function(), f()
  • A version of substitute that uses regular evaluation, substitute_q(), and one that will substitute objects in the global environment, subs()
  • Tools to modify language objects: modify_lang()
  • dots() and named_dots() to get unevaluated ...
  • Partial function evaluation: partial()
  • Find all functions matching some criteria: find_funs()

• To use existing R tools more easily:

  • %<d-% and %<a-% for creating delayed or active bindings
  • %<c-% for creating constants (locked bindings)
  • rebind as a more user friendly version of <<-