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ternary operator in R
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| # A ternary operator in R. | |
| if (!is.element("super", installed.packages()[,1])) { devtools::install_github("robertzk/super") } | |
| `?` <- function(expr1, expr2) { | |
| if (missing(expr2)) { | |
| super::super(expr1) | |
| } else { | |
| expr2 <- substitute(expr2) | |
| if (!(is.call(expr2) && identical(expr2[[1]], as.name(":")))) { | |
| super::super(expr1, expr2) | |
| } else { | |
| condition <- eval.parent(expr1) | |
| stopifnot(is.logical(condition) && length(condition) == 1) | |
| if (condition) { | |
| eval.parent(expr2[[2]]) | |
| } else { | |
| eval.parent(expr2[[3]]) | |
| } | |
| } | |
| } | |
| } | |
| # > TRUE ? 1 : 2 | |
| # [1] 1 | |
| # > TRUE ? 2 : 1 | |
| # [1] 2 | |
| # > 1 == 2 ? 3 : 4 | |
| # [1] 4 |
Oh, even more awesome than I thought.
Make a package out of it? Put it in a package?
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And
super::supertakes care of ensuring correct behavior onbase::"?"