factor/extra/base85/base85.factor

74 lines
2.1 KiB
Factor

! Copyright (C) 2013 John Benediktsson.
! See http://factorcode.org/license.txt for BSD license.
USING: base64 base64.private combinators fry io io.binary
io.encodings.binary io.streams.byte-array kernel math
namespaces sequences ;
IN: base85
ERROR: malformed-base85 ;
<PRIVATE
: ch>base85 ( ch -- ch )
"0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz!#$%&()*+-;<=>?@^_`{|}~\";"
nth ; inline
: base85>ch ( ch -- ch )
{
f f f f f f f f f f f f f f f f f f f f f f f f f f f f
f f f f f 62 f 63 64 65 66 f 67 68 69 70 f 71 f f 0 1 2
3 4 5 6 7 8 9 f 72 73 74 75 76 77 10 11 12 13 14 15 16
17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35
f f f 78 79 80 36 37 38 39 40 41 42 43 44 45 46 47 48 49
50 51 52 53 54 55 56 57 58 59 60 61 81 82 83 84
} nth [ malformed-base85 ] unless* ; inline
: encode4 ( seq -- )
column output-stream get '[
swap be> 5 [ 85 /mod ch>base85 ] replicate
reverse! nip [ _ write1-lines ] each
] change ; inline
: (encode-base85) ( stream -- )
4 over stream-read dup length {
{ 0 [ 2drop ] }
{ 4 [ encode4 (encode-base85) ] }
[ drop 4 0 pad-tail encode4 (encode-base85) ]
} case ;
PRIVATE>
: encode-base85 ( -- )
input-stream get (encode-base85) ;
: encode-base85-lines ( -- )
0 column [ encode-base85 ] with-variable ;
<PRIVATE
: decode5 ( seq -- )
0 [ [ 85 * ] [ base85>ch ] bi* + ] reduce 4 >be
[ zero? ] trim-tail-slice output-stream get
'[ _ stream-write1 ] each ; inline
: (decode-base85) ( stream -- )
5 "\n\r" pick read-ignoring dup length {
{ 0 [ 2drop ] }
{ 5 [ decode5 (decode-base85) ] }
[ malformed-base85 ]
} case ;
PRIVATE>
: decode-base85 ( -- )
input-stream get (decode-base85) ;
: >base85 ( seq -- base85 )
binary [ binary [ encode-base85 ] with-byte-reader ] with-byte-writer ;
: base85> ( base85 -- seq )
binary [ binary [ decode-base85 ] with-byte-reader ] with-byte-writer ;
: >base85-lines ( seq -- base85 )
binary [ binary [ encode-base85-lines ] with-byte-reader ] with-byte-writer ;