pryr: Tools for Computing on the Language

Useful tools to pry back the covers of R and understand the language at a deeper level.

Install the latest version of this package by entering the following in R:
AuthorHadley Wickham [aut, cre], R Core team [ctb] (Some code extracted from base R)
Date of publication2015-06-20 00:35:21
MaintainerHadley Wickham <>

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Man pages

as.envlist: Convert a list of environments to an 'envlist' object.

assign-active: Create an active binding.

assign-constant: Create a constant (locked) binding.

assign-delayed: Create an delayed binding.

bytes: Print the byte-wise representation of a value

call_tree: Display a call (or expression) as a tree.

compose: Compose multiple functions

dots: Capture unevaluated dots.

enclosing_env: Find the environment that encloses of a function.

explicit: Tools for making promises explicit

f: A compact syntax for anonymous functions.

fget: Find a function with specified name.

find_funs: Find functions matching criteria.

find_uses: Find all functions in that call supplied functions.

ftype: Determine function type.

inspect: Inspect internal attributes of R objects.

is_active_binding: Active binding info

is_promise: Promise info

is_s3_generic: Determine if a function is an S3 generic or S3 method.

make_call: Make and evaluate calls.

make_function: Make a function from its components.

mem_change: Determine change in memory from running code

mem_used: How much memory is currently used by R?

method_from_call: Given a function class, find correspoding S4 method

modify_call: Modify the arguments of a call.

modify_lang: Recursively modify a language object

names_c: Extract function table from names.c from R subversion...

object_size: Compute the size of an object.

otype: Determine object type.

parent_promise: Find the parent (first) promise.

parenv: Get parent/ancestor environment

parenvs: Given an environment or object, return an 'envlist' of its...

partial: Partial apply a function, filling in some arguments.

print.envlist: Print an 'envlist'

rebind: Rebind an existing name.

rls: Recursive ls.

show_c_source: Find C source code for internal R functions

standardise_call: Standardise a function call

subs: A version of substitute that works in the global environment.

substitute_q: A version of substitute that evaluates its first argument.

track_copy: Track if an object is copied

unenclose: Unenclose a closure.

uneval: Capture the call associated with a promise.

where: Find where a name is defined.


\%.\% Man page
\%<a-\% Man page
address Man page
as.envlist Man page
ast Man page
bits Man page
bytes Man page
\%<c-\% Man page
call_tree Man page
compare_size Man page
compose Man page
\%<d-\% Man page
do_call Man page
dots Man page
enclosing_env Man page
eval2 Man page
explicit Man page
f Man page
fget Man page
find_funs Man page
find_uses Man page
ftype Man page
fun_args Man page
fun_body Man page
fun_calls Man page
inspect Man page
is_active_binding Man page
is_promise Man page
is_s3_generic Man page
is_s3_method Man page
make_call Man page
make_function Man page
mem_change Man page
mem_used Man page
method_from_call Man page
modify_call Man page
modify_lang Man page
named_dots Man page
names_c Man page
object_size Man page
otype Man page
parent_promise Man page
parenv Man page
parenvs Man page
partial Man page
print.envlist Man page
promise_info Man page
rebind Man page
refs Man page
rls Man page
sexp_type Man page
show_c_source Man page
standardise_call Man page
subs Man page
substitute_q Man page
track_copy Man page
typename Man page
unenclose Man page
uneval Man page
where Man page


tests/testthat/test-ftype.r tests/testthat/test-object_size.R tests/testthat/test-bytes.r tests/testthat/test-method-from-call.r tests/testthat/test-active-binding.r tests/testthat/test-track-copy.R
R/rls.r R/dots.r R/uneval.r R/substitute.r R/modify-lang.r R/modify-call.R R/assign-constant.r R/find-funs.r R/explicit-promise.R R/rebind.r R/method-from-call.r R/standardise-call.r R/ftype.r R/names_c.R R/utils.r R/inspect.r R/assign-active.r R/make-call.R R/s3.r R/make-function.r R/enclosing.R R/compose.r R/promise.r R/RcppExports.R R/f.r R/fget.r R/unenclose.r R/draw-tree.r R/where.r R/otype.r R/bytes.r R/object_size.R R/assign-delayed.r R/find_uses.R R/active.r R/parenv.r R/mem.R R/partial.r
man/is_active_binding.Rd man/parenvs.Rd man/assign-constant.Rd man/compose.Rd man/as.envlist.Rd man/parent_promise.Rd man/print.envlist.Rd man/uneval.Rd man/where.Rd man/modify_lang.Rd man/rls.Rd man/explicit.Rd man/mem_change.Rd man/is_s3_generic.Rd man/fget.Rd man/enclosing_env.Rd man/names_c.Rd man/partial.Rd man/track_copy.Rd man/bytes.Rd man/find_funs.Rd man/rebind.Rd man/method_from_call.Rd man/show_c_source.Rd man/object_size.Rd man/dots.Rd man/find_uses.Rd man/modify_call.Rd man/make_call.Rd man/unenclose.Rd man/assign-delayed.Rd man/ftype.Rd man/make_function.Rd man/standardise_call.Rd man/assign-active.Rd man/parenv.Rd man/is_promise.Rd man/call_tree.Rd man/inspect.Rd man/f.Rd man/otype.Rd man/subs.Rd man/mem_used.Rd man/substitute_q.Rd
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