Pry open the covers of R
R C++ C
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Latest commit 5b11749 Feb 18, 2018

pryr (rhymes with pry bar)

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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").


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 <<-