rtype is a strong type system for R which supports symbol declaration and assignment with type checking.
You can install the latest released version from CRAN with
install.packages("rtype")or the latest development version from GitHub with
devtools::install_github("rtype","renkun-ken")Declare symbols Before using them.
library(rtype)
declare(x,y=numeric(),z=logical())
ls.str()x : NULL
y : num(0)
z : logi(0) # NULL symbol can be assigned any value
numeric(x) <- c(1,2,3.5)
# numeric symbol can be assigned only numeric value
# is.numeric(y) = TRUE, and is.numeric(c(1,2,3)) = TRUE
numeric(y) <- c(1,2,3)
# the symbol does not take value that violates its type checking
# is.integer(y) = FALSE (violation)
integer(y) <- c(1L,2L)Error: symbol fails type checking with .Primitive("is.integer")# the assignment fails if the value does not pass type checking
# is.logical(z) = TRUE, but is.logical(c(1,2,3)) = FALSE (violation)
logical(z) <- c(1,2,3)Error: value fails type checking with .Primitive("is.logical")Checking single condition
# assign value checking condition length = 3
numeric(x, length = 3) <- c(1,2,3)
# stop if condition is violated
numeric(x, length = 3) <- c(1,2,3,4)Error: value [length = 4L] violates condition [length = 3]Checking multiple conditions
# assign value checking multiple conditions
declare(df)
data.frame(df, ncol=2, nrow=10) <- data.frame(x=1:10,y=letters[1:10])
# or equivalently
data.frame(df, dim=c(10,2)) <- data.frame(x=1:10,y=letters[1:10])
# stop if any condition is violated
data.frame(df, ncol=3, nrow=10) <- data.frame(x=1:10,y=letters[1:10])Error: value [ncol = 2L] violates condition [ncol = 3]Checking function conditions
# checking function condition
declare(x)
cond1 <- function(x) mean(x) <= 5
numeric(x, length = 10, cond1) <- 0:9
numeric(x, length = 10, cond1) <- 1:10Error: value violates condition [function (x) mean(x) <= 5]General checking
declare(x)
check(x, class="integer", length=10) <- 1:10
check(x, class="numeric", length=10) <- 1:10Error: value [class = "integer"] violates condition [class = "numeric"]help(package = rtype)This package is under MIT License.