On 2/15/21 1:10 PM, Hadley Wickham wrote:
This is a nice example of the motivation for tidy evaluation — since
enquo() captures the environment in which the promise should be
evaluated, there's no need for an additional explicit argument.
library(rlang)
replicate2 <- function (n, expr, simplify = "array") {
exnr <- enquo(expr)
It does not appear that the line above would accomplish anything given
the succeeding line. Or am I missing something? Taking it out doesn't
seem to affect results. Whatever magic there is seems to be in the
`eval_tidy` function, whose mechanism or rules seem opaque. Was "exnr"
supposed to be passed to `eval_tidy`?
--
David.
sapply(integer(n), function(i) eval_tidy(expr), simplify = simplify)
}
doRep2 <- function(a, b) sapply(a, replicate2, b)
doRep2(3, 2)
#> [,1]
#> [1,] 2
#> [2,] 2
#> [3,] 2
Hadley
On Sat, Feb 13, 2021 at 7:09 AM Gabor Grothendieck
<ggrothendi...@gmail.com> wrote:
Currently replicate used within sapply within a function can fail
because it gets the environment for its second argument, which is
currently hard coded to be the parent frame, wrong. See this link for
a full example of how it goes wrong and how it could be made to work
if it were possible to pass an envir argument to it.
https://stackoverflow.com/questions/66184446/sapplya-replicate-b-expression-no-longer-works-inside-a-function/66185079#66185079
--
Statistics & Software Consulting
GKX Group, GKX Associates Inc.
tel: 1-877-GKX-GROUP
email: ggrothendieck at gmail.com
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