Created
July 17, 2019 03:10
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Evaluate a list lazily
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| # Taken from: https://twitter.com/dirk_sch/status/1151080975952228352 | |
| "[[.ll" <- function(x, i) { | |
| rlang::eval_tidy(x$call_list[[i]]) | |
| } | |
| lazylist <- function(...) { | |
| calls <- rlang::enexprs(...) | |
| structure(list(call_list = calls), class = "ll") | |
| } | |
| a <- lazylist(1, 2, Sys.sleep(10), 10) | |
| a[[2]] | |
| #> [1] 2 |
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