Description Usage Arguments Note Note Author(s) Examples
View source: R/utils--DoCall.R
The base::do.call()
can be somewhat slow, especially when
working with large objects. This function is based upon the suggestions from
Hadley Wickham on the R mailing list
(link).
Also thanks to Tommy at StackOverflow
(link)
for how to handle double and triple colon operators, ::
, further
enhancing the function.
1 | DoCall(what, args, quote = FALSE, envir = parent.frame())
|
what |
either a function or a non-empty character string naming the function to be called. |
args |
a list of arguments to the function call. The |
quote |
a logical value indicating whether to quote the arguments. |
envir |
an environment within which to evaluate the call. This will be
most useful if |
While the function attempts to do most of what base::do.call()
can it has limitations. It can currently not parse the example code from
the original function:
do.call(paste, list(as.name("A"), as.name("B")), quote = TRUE)
and the funcitonality of quote
has not been thoroughly tested.
This function is a verbatim copy from Gmisc::fastDoCall()
Max Gordon max@gforge.se
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 | DoCall("complex", list(imaginary = 1:3))
## if we already have a list (e.g. a data frame)
## we need c() to add further arguments
tmp <- expand.grid(letters[1:2], 1:3, c("+", "-"))
DoCall("paste", c(tmp, sep = ""))
## examples of where objects will be found.
A <- 2
f <- function(x) print(x^2)
env <- new.env()
assign("A", 10, envir = env)
assign("f", f, envir = env)
f <- function(x) print(x)
f(A) # 2
DoCall("f", list(A)) # 2
DoCall("f", list(A), envir = env) # 4
DoCall(f, list(A), envir = env) # 2
DoCall("f", list(quote(A)), envir = env) # 100
DoCall(f, list(quote(A)), envir = env) # 10
DoCall("f", list(as.name("A")), envir = env) # 100
eval(call("f", A)) # 2
eval(call("f", quote(A))) # 2
eval(call("f", A), envir = env) # 4
eval(call("f", quote(A)), envir = env) # 100
|
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