base64: use literals to compute the inverse array instead of hardcoding.

db4
John Benediktsson 2015-07-15 18:19:59 -07:00
parent 4cf54117ee
commit 027a71d98e
1 changed files with 14 additions and 12 deletions

View File

@ -1,8 +1,8 @@
! Copyright (C) 2008 Doug Coleman, Daniel Ehrenberg.
! See http://factorcode.org/license.txt for BSD license.
USING: combinators fry io io.binary io.encodings.binary
io.streams.byte-array kernel math namespaces sbufs
sequences strings ;
USING: arrays combinators fry io io.binary io.encodings.binary
io.streams.byte-array kernel literals math namespaces sbufs
sequences ;
IN: base64
ERROR: malformed-base64 ;
@ -21,18 +21,20 @@ ERROR: malformed-base64 ;
'[ _ _ read1-ignoring push-ignoring ] times
[ f ] [ "" like ] if-empty ; inline
: ch>base64 ( ch -- ch )
CONSTANT: alphabet
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
nth ; inline
: alphabet-inverse ( alphabet -- seq )
dup supremum 1 + f <array> [
'[ swap _ set-nth ] each-index
] keep ;
: ch>base64 ( ch -- ch )
alphabet nth ; inline
: base64>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
f f f f f f f f f f 62 f f f 63 52 53 54 55 56 57 58 59 60 61 f f
f 0 f f f 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21
22 23 24 25 f f f f f f 26 27 28 29 30 31 32 33 34 35 36 37 38 39
40 41 42 43 44 45 46 47 48 49 50 51
} nth [ malformed-base64 ] unless* ; inline
$[ alphabet alphabet-inverse 0 CHAR: = pick set-nth ] nth
[ malformed-base64 ] unless* ; inline
SYMBOL: column