pryr (version 0.1.6)

track_copy: Track if an object is copied

Description

The title is somewhat misleading: rather than checking if an object is modified, this really checks to see if a name points to the same object.

Usage

track_copy(var, env = parent.frame(), quiet = FALSE)

Value

a zero-arg function, that when called returns a boolean indicating if the object has changed since the last time this function was called

Arguments

var

variable name (unquoted)

env

environment name in which to track changes

quiet

if FALSE, prints a message on change; if FALSE only the return value of the function is used

Examples

a <- 1:5
track_a <- track_copy(a)
track_a()
a[3] <- 3L
track_a()
a[3] <- 3
track_a()
rm(a)
track_a()