base92> ( base92 -- seq )
Base92 conversions

Prev:

>base92 ( seq -- base92 )

Vocabulary
base92

Inputs

base92

a sequence

Outputs

seq	a sequence

Word description
Decode from Base92 encoding.

Definition

USING: base92.private combinators kernel math sequences
sequences.private ;

IN: base92

:: base92> ( base92 -- seq )
    base92 length :> len {
        { [ len 0 = ] [ B{ } clone ] }
        { [ len 1 = base92 first 126 = and ] [ B{ } clone ] }
        { [ len 2 < ] [ f ] }
        [
            0 :> b! 0 :> n! BV{ } clone :> accum len 2/ <iota> [
                2 * dup 1 + [ base92 nth-unsafe base92>ch ] bi@
                [ 91 * ] dip + b 13 shift bitor b! n 13 + n!
                [ n 8 >= ] [
                    b n 8 - neg shift 255 bitand accum push
                    n 8 - n!
                ] while
            ] each len odd? [
                len 1 - base92 nth-unsafe base92>ch b 6 shift
                bitor b! n 6 + n!
                [ n 8 >= ] [
                    b n 8 - neg shift 255 bitand accum push
                    n 8 - n!
                ] while
            ] when accum B{ } like
        ]
    } cond ;