Constructing quines (self-reproducing functions)

Question

Has anyone constructed a quine (\"A program that generates a copy of its own source text as its complete output\": http://www.nyx.net/~gthompso/quine.htm) in R? (The [quine] ta

Answer 1

Here is a real Quine, a program (not a function) that generates a copy of its own source text as its complete output.

On console,

# y1.R is a quine program
$ cat y1.R
(function(x){cat(x);cat('(');cat(intToUtf8(0x0022));cat(x);cat(intToUtf8(0x0022));cat(')')})("(function(x){cat(x);cat('(');cat(intToUtf8(0x0022));cat(x);cat(intToUtf8(0x0022));cat(')')})")

# execute y1.R and show output
$ /usr/bin/R --vanilla --slave < y1.R
(function(x){cat(x);cat('(');cat(intToUtf8(0x0022));cat(x);cat(intToUtf8(0x0022));cat(')')})("(function(x){cat(x);cat('(');cat(intToUtf8(0x0022));cat(x);cat(intToUtf8(0x0022));cat(')')})")

# save the output of the execution of y1
$ /usr/bin/R --vanilla --slave < y1.R > y2.R

# compare input and output -- exactly same.
$ diff y1.R y2.R

probably this is not the shortest one.

UPDATED:

and slightly shorter version:

(function(x){cat(x,'(',d<-intToUtf8(0x0022),x,d,')',sep='')})("(function(x){cat(x,'(',d<-intToUtf8(0x0022),x,d,')',sep='')})")