pryr: track_copy – R documentation

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track_copy

Track if an object is copied

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.

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

`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

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

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

Tools for Computing on the Language

v0.1.4

GPL-2

Authors

Hadley Wickham [aut, cre], R Core team [ctb] (Some code extracted from base R)

Initial release