byte-reverse ( n signed? -- quot )
Alien endian-aware types

Next:

be8

Vocabulary
alien.endian

Inputs

n	an integer
signed?	a boolean

Outputs

quot	a quotation

Word description
Reverses the n bytes in an integer with bitwise operations. The second parameter only works for 1, 2, 4, or 8 byte signed numbers.

Definition

USING: combinators generalizations kernel math sequences ;

IN: alien.endian

MACRO: byte-reverse ( n signed? -- quot )
    [
        drop [
            dup <iota> [
                [ 1 + - -8 * ] [ nip 8 * ] 2bi
                [ [ shift 255 bitand ] curry ] dip
                [ shift ] curry compose
            ] with map
        ] [ 1 - [ bitor ] n*quot ] bi
    ] [ [ convert-signed-quot ] [ drop [ ] ] if ] 2bi
    [ [ [ cleave ] curry ] dip compose ] dip compose ;