metaprogramming

# Classic character vector
paste0("as",".","numeric")

# getting a function 
get(paste0("as",".","numeric"))

# getting and running a function
get(paste0("as",".","numeric"))("1")

# With objects
x <- "as"
y <- "is"
get(paste0(x,".","numeric"))("1")
get(paste0(y,".","numeric"))("1")

# Another function 
action_type_what <- function(action, type, what){
  get(paste0(action,".",type))(what)
}

action_type_what("is", "numeric", "1")
action_type_what("as", "numeric", "1")
action_type_what("is", "character", 1)
action_type_what("as", "character", 1)