Memoize the result of an expression in R

gistfile1.r

require(rredis)

redisConnect()

memoize <- function(expr, key=NULL, expire_time=Inf, verbose=FALSE,
                    envir=parent.frame()) {
  if (is.null(key)) {
    key <- paste(substitute(expr), collapse="")
  }
  if (redisExists(key)) {
    ret <- redisGet(key)
  } else {
    ret <- eval(substitute(expr), envir=envir)
    redisSet(key, ret)
  }
  if (expire_time < Inf) {
    redisExpireAt(proj_doc_key,
      as.integer(as.POSIXct(Sys.time())+expire_time))
  }
  ret
}