Example code for https://aksela.wordpress.com/2018/08/18/simple-example-for-creating-a-custom-s3-class-with-methods/

text class 1.r

sampletext <- "Technically, five-bit codes began in the 17th century, when Francis Bacon developed the cipher now called Bacon's cipher. The cipher was not designed for machine telecommunications (it was instead a method of encrypting a hidden message into another) and, although in theory it could be adapted to that purpose, it only covered 24 of the 26 letters of the English alphabet (two sets of letters, I/J and U/V, were expressed with the same code) and contained no punctuation, spaces, numbers or control characters, rendering it of little use."

sampletext
#[1] "Technically, five-bit codes began in the 17th century, when Francis Bacon developed the cipher now called Bacon's cipher. The cipher was not designed for machine telecommunications (it was instead a method of encrypting a hidden message into another) and, although in theory it could be adapted to that purpose, it only covered 24 of the 26 letters of the English alphabet (two sets of letters, I/J and U/V, were expressed with the same code) and contained no punctuation, spaces, numbers or control characters, rendering it of little use."

text class 2.r

cl.pr <- sub("print.", "", c(methods(print)))
cl.pl <- sub("plot.", "", c(methods(plot)))
cl.su <- sub("summary.", "", c(methods(summary)))
cl.un <- Reduce(union, list(cl.pr, cl.pl, cl.su))
sort(cl.un)

text class 3.r

class(sampletext) <- c("text", "character")
class(sampletext)
#[1] "text"      "character"

text class 4.r

print.text <- function(x, width=80) {
	x <- strwrap(x, width)
	cat(x, sep="\n")
}

sampletext
# Technically, five-bit codes began in the 17th century, when Francis Bacon
# developed the cipher now called Bacon's cipher. The cipher was not designed for
# machine telecommunications (it was instead a method of encrypting a hidden
# message into another) and, although in theory it could be adapted to that
# purpose, it only covered 24 of the 26 letters of the English alphabet (two sets
# of letters, I/J and U/V, were expressed with the same code) and contained no
# punctuation, spaces, numbers or control characters, rendering it of little use.

text class 5.r

statmode <- function(...) {
	UseMethod("statmode")
}

text class 6.r

statmode.text <- function(x) {
	lett <- tolower(gsub("[^a-zA-z]", "", x))
	fact <- factor(strsplit(lett, "")[[1]])
	tabl <- table(fact)
	tabl[which.max(tabl)]
}

statmode.character <- function(x) {
	word <- tolower(sub("'.*", "", x))
	tabl <- table(word)
	tabl[which.max(tabl)]
}

statmode.numeric <- function(x, na.rm=FALSE) {
    if (na.rm) {
      x <- x[!is.na(x)]
    }
    ux <- unique(x)
    ux[which.max(tabulate(match(x, ux)))]
}

statmode.default <- function(x) {
	tabl <- table(x)
	tabl[which.max(tabl)]	
}

text class 7.r

sampletext.char <- unlist(strsplit(gsub("[,.()]", "", sampletext), " "))
sample.num <- c(1, 3, 2, 7, 9, 0, 5, 3, 1, 6, 7, 5, 2, 4, 7, 4, 0, 7, 1, 8)
sample.fac <- factor(sample.num)

statmode(sampletext)
#  e 
# 59 

statmode(sampletext.char)
# the 
#   6 

statmode(sample.num)
# [1] 7

statmode(sample.fac)
# 7 
# 4