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 <<-