hex-string>bytes ( hex-string -- bytes )
Hex Strings

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Vocabulary
hex-strings

Inputs

hex-string

a sequence

Outputs

bytes

a byte-array

Word description
Converts a sequence of hex numbers in the range [00,ff] to a sequence of bytes (integers in the range [0,255]).

Examples

USING: hex-strings prettyprint ; "cafebabe" hex-string>bytes .
B{ 202 254 186 190 }

See also
bytes>hex-string

Definition

USING: byte-arrays kernel math math.parser sequences
sequences.private ;

IN: hex-strings

: hex-string>bytes ( hex-string -- bytes )
    dup length dup even? [ invalid-hex-string-length ] unless
    2/ <byte-array> [
        [
            [ digit> ] 2dip over even?
            [ [ 16 * ] [ 2/ ] [ set-nth-unsafe ] tri* ]
            [ [ 2/ ] [ [ + ] change-nth-unsafe ] bi* ] if
        ] curry each-index
    ] keep ;