## ----include = FALSE---------------------------------------------------------- library(optional) ## ----------------------------------------------------------------------------- a <- option(5) class(a) ## ----------------------------------------------------------------------------- a == 5 a ## ----------------------------------------------------------------------------- a <- option(5) some(a) a <- none some(a) ## ----------------------------------------------------------------------------- c_opt <- make_opt(c) c_opt(option(2), none, option(5)) c_opt() ## ----------------------------------------------------------------------------- library(magrittr) a <- 5 match_with(a, . %>% option(.), paste, none, function() "Error!" ) ## ----------------------------------------------------------------------------- a <- 4 match_with(a, 1, function() "Matched exact value", list(2, 3, 4), fallthrough(function() "Matched in list"), . %>% if (. > 3)., function(x) paste0("Matched in condition: ",x,">3") )