rtype is a strong type system for R which supports symbol declarationand assignment with type checking.
You can install the latest released version fromCRAN 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 : NULLy : num(0) z : logi(0)# NULL symbol can be assigned any valuenumeric(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)) = TRUEnumeric(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 = 3numeric(x,length =3)<-c(1,2,3)# stop if condition is violatednumeric(x,length =3)<-c(1,2,3,4)Error: value [length = 4L] violates condition [length = 3]Checking multiple conditions
# assign value checking multiple conditionsdeclare(df)data.frame(df,ncol=2,nrow=10)<-data.frame(x=1:10,y=letters[1:10])# or equivalentlydata.frame(df,dim=c(10,2))<-data.frame(x=1:10,y=letters[1:10])# stop if any condition is violateddata.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 conditiondeclare(x)cond1<-function(x)mean(x)<=5numeric(x,length =10, cond1)<-0:9numeric(x,length =10, cond1)<-1:10Error: value violates condition [function (x) mean(x) <= 5]General checking
declare(x)check(x,class="integer",length=10)<-1:10check(x,class="numeric",length=10)<-1:10Error: value [class = "integer"] violates condition [class = "numeric"]help(package = rtype)This package is underMIT License.