>The program is smaller than even the 'compressed' form of its output,
>and thus represents a new departure in text compression standards.
7z and gzip disagree with this statement.
>and thus represents a new departure in text compression standards.
7z and gzip disagree with this statement.
For reference:
1490 xmas-with-leading-comment.c
913 xmas-without-leading-comment.c
2357 xmas.out
1297 xmas.out.9.Z
1038 xmas.out.10.Z # actually better than with more bits!
1048 xmas.out.11.Z # compression with 11..16 bits have the same size
319 xmas.out.1.gz # compression levels 1..2 has same size
317 xmas.out.3.gz
307 xmas.out.4.gz # compression levels 4..9 have same size
% gcc xmas.c
xmas.c:2:1: warning: return type defaults to 'int' [-Wimplicit-int]
2 | main(t,_,a)
| ^~~~
xmas.c: In function 'main':
xmas.c:2:1: warning: type of 't' defaults to 'int' [-Wimplicit-int]
xmas.c:2:1: warning: type of '_' defaults to 'int' [-Wimplicit-int]
% wc -c <xmas.c
913
% ./a.out | wc -c
2359
% ./a.out | compress | wc -c
1048To be a fair comparison, though, you'd have to write zstd -d in 604 bytes. I suppose to be REALLY fair, though, you have to count the bytes of code in the compiler itself. A convenient enough implementation of compression could index into the C compiler binary to find the bytes it needs. (For example, my GCC contains "first", "second", and "third" in the binary, which a sufficiently clever implementation could make use of. "Exit on the first error occurred.", "Append a second underscore if the name already contains an underscore.", "Warn about suspicious calls to memset where the third argument is constant literal zero and the second is not.", etc. I didn't check but I doubt turtle doves or maids-a-milking come up that often in the description of warning flags.)
https://www.nic.funet.fi/index/minix/compress.c
The program that produces the song, without the introductory comment, is 913 bytes, as presented in the article. Removing whitespaces it uses just 800 bytes and produces the song which is 2359 chars here. The whole C is:
main(t,_,a)char*a;{return!0<t?t<3?main(-79,-13,a+main(-87,1-_,
main(-86,0,a+1)+a)):1,t<_?main(t+1,_,a):3,main(-94,-27+t,a)&&t==
2?_<13?main(2,_+1,"%s%d%d\n"):9:16:t<0?t<-72?main(_,t,
"@n'+,#'/*{}w+/w#cdnr/+,{}r/*de}+,/*{*+,/w{%+,/w#q#n+,/#{l,+,/n{n+,/+#n+,/#;\
#q#n+,/+k#;*+,/'r :'d*'3,}{w+K w'K:'+}e#';dq#'l q#'+d'K#!/+k#;\
q#'r}eKK#}w'r}eKK{nl]'/#;#q#n'){)#}w'){){nl]'/+#n';d}rw' i;# ){nl]!/n{n#'; \
r{#w'r nc{nl]'/#{l,+'K {rw' iK{;[{nl]'/w#q#\
\
n'wk nw' iwk{KK{nl]!/w{%'l##w#' i; :{nl]'/*{q#'ld;r'}{nlwb!/*de}'c ;;\
{nl'-{}rw]'/+,}##'*}#nc,',#nw]'/+kd'+e}+;\
#'rdq#w! nr'/ ') }+}{rl#'{n' ')# }'+}##(!!/")
:t<-50?_==*a?putchar(31[a]):main(-65,_,a+1):main((*a=='/')+t,_,a+1):
0<t?main(2,2,"%s"):*a=='/'||main(0,main(-61,*a,
"!ek;dc i@bK'(q)-[w]*%n+r3#l,{}:\nuwloca-O;m .vpbks,fxntdCeghiry"),a+1);}
It took it from 2357 bytes to 534 bytes, which is smaller than the Xmas.c program which I counted as 917 bytes, but another poster counted 913 bytes.