ifelse sugar

gistfile1.r

#             DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
#                     Version 2, December 2004
#
#  Copyright (C) 2004 Sam Hocevar <sam@hocevar.net>
#
#  Everyone is permitted to copy and distribute verbatim or modified
#  copies of this license document, and changing it is allowed as long
#  as the name is changed.
#
#             DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
#    TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
#
#   0. You just DO WHAT THE FUCK YOU WANT TO.


### DEAR ORACLE, PLS DONT SUE

decode <- function(x, ...)
{
  l <- list(...)
  evenodd <- length(l) %% 2
  
  pos <- 1L
  
  while (pos < (length(l) - evenodd))
  {
    if (x == l[[pos]])
      return(l[[pos+1L]])
    
    pos <- pos + 2L
  }
  
  if (evenodd)
    return(l[[pos]])
  else
    return(NULL)
}


decode(2, 1, "thing", 2, "other thing", "default")
decode(3, 1, "thing", 2, "other thing", "default")

decode(2, 1, "thing", 2, "other thing")
decode(3, 1, "thing", 2, "other thing")