source_selection {tinycodet} | R Documentation |
The source_selection()
function is the same as
base R's source function, except that it allows only placing
the selected objects and functions into the current environment,
instead of all objects.
The objects to be selected can be specified using any combination of the following:
by supplying a character vector of exact object names to the select
argument.
by supplying a character vector of regex
patterns to the regex
argument.
by supplying a character vector of fixed
patterns to the fixed
argument.
Note that the source_selection()
function does NOT suppress output
(i.e. plots, prints, messages)
from the sourced script file.
source_selection(lst, select = NULL, regex = NULL, fixed = NULL)
lst |
a named list, giving the arguments to be passed to the
source function. |
select |
a character vector, giving the exact names of the functions or objects appearing in the script, to expose to the current environment. |
regex |
a character vector of |
fixed |
a character vector of |
One can specify which objects to expose using arguments
select
, regex
, or fixed
.
The user can specify all 3 of them, but at least one of the 3 must be specified.
It is not a problem if the specifications overlap.
Any specified objects will be placed
in the current environment
(like the Global environment, or the environment within a function).
tinycodet_misc, base::source()
exprs <- expression({
helloworld = function()print("helloworld")
goodbyeworld <- function() print("goodbye world")
`%s+test%` <- function(x,y) stringi::`%s+%`(x,y)
`%s*test%` <- function(x,y) stringi::`%s*%`(x,y)
mymethod <- function(x) UseMethod("mymethod", x)
mymethod.numeric <- function(x)x * 2
mymethod.character <- function(x)chartr(x, old = "a-zA-Z", new = "A-Za-z")
})
source_selection(list(exprs=exprs), regex = "^mymethod")
mymethod(1)
mymethod("a")
temp.fun <- function(){
source_selection(list(exprs=exprs), regex = "^mymethod", fixed = c("%", ":="))
ls() # list all objects residing within the function definition
}
temp.fun()
temp.fun <- function(){
source_selection(list(exprs=exprs), select = c("helloworld", "goodbyeworld"))
ls() # list all objects residing within the function definition
}
temp.fun()