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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 <<-

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Version

Install

install.packages('pryr')

Monthly Downloads

20,460

Version

0.1.2

License

GPL-2

Issues

23

Pull Requests

11

Stars

203

Forks

43

Maintainer

Hadley Wickham

Last Published

June 20th, 2015

Functions in pryr (0.1.2)

as.envlist

Convert a list of environments to an envlist object.
f

A compact syntax for anonymous functions.
show_c_source

Find C source code for internal R functions
%

Create an active binding.
compose

Compose multiple functions
is_promise

Promise info
mem_used

How much memory is currently used by R?
unenclose

Unenclose a closure.
otype

Determine object type.
enclosing_env

Find the environment that encloses of a function.
find_funs

Find functions matching criteria.
rebind

Rebind an existing name.
is_active_binding

Active binding info
make_call

Make and evaluate calls.
sexp_type

Inspect internal attributes of R objects.
names_c

Extract function table from names.c from R subversion repository.
bytes

Print the byte-wise representation of a value
substitute_q

A version of substitute that evaluates its first argument.
find_uses

Find all functions in that call supplied functions.
standardise_call

Standardise a function call
ftype

Determine function type.
uneval

Capture the call associated with a promise.
mem_change

Determine change in memory from running code
rls

Recursive ls.
parenv

Get parent/ancestor environment
method_from_call

Given a function class, find correspoding S4 method
%

Create a constant (locked) binding.
call_tree

Display a call (or expression) as a tree.
make_function

Make a function from its components.
modify_lang

Recursively modify a language object
parenvs

Given an environment or object, return an envlist of its parent environments.
object_size

Compute the size of an object.
dots

Capture unevaluated dots.
fget

Find a function with specified name.
is_s3_generic

Determine if a function is an S3 generic or S3 method.
modify_call

Modify the arguments of a call.
partial

Partial apply a function, filling in some arguments.
track_copy

Track if an object is copied
where

Find where a name is defined.
parent_promise

Find the parent (first) promise.
%

Create an delayed binding.
print.envlist

Print an envlist
subs

A version of substitute that works in the global environment.
explicit

Tools for making promises explicit
%<a-%

Create an active binding.
%<c-%

Create a constant (locked) binding.
%<d-%

Create an delayed binding.