parse-delta ( -- delta/f )

Vocabulary

git

Inputs

None

Outputs

delta/f

an object

Definition

USING: io kernel math math.bitwise ;

IN: git

: parse-delta ( -- delta/f )
    read1 [
        dup 128 mask? not
        [ 7 bits read <insert> ] [
            [ 0 0 ] dip dup 1 mask?
            [ [ read1* bitor ] 2dip ] when dup 2 mask?
            [ [ read1* 8 shift bitor ] 2dip ] when dup 4 mask?
            [ [ read1* 16 shift bitor ] 2dip ] when dup 8 mask?
            [ [ read1* 24 shift bitor ] 2dip ] when dup 16 mask?
            [ [ read1* bitor ] dip ] when dup 32 mask?
            [ [ read1* 8 shift bitor ] dip ] when dup 64 mask?
            [ [ read1* 16 shift bitor ] dip ] when drop
            [ 65536 ] when-zero <copy>
        ] if
    ] [ f ] if* ;