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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 |
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Make a package out of it? Put it in a package?