inst/doc/UserGuide.R

## ----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")
)

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optional documentation built on May 1, 2019, 9:14 p.m.