\ Challenge 119
\
\ TASK #1 - Swap Nibbles
\ Submitted by: Mohammad S Anwar
\ You are given a positive integer $N.
\
\ Write a script to swap the two nibbles of the binary representation of the
\ given number and print the decimal number of the new binary representation.
\
\ A nibble is a four-bit aggregation, or half an octet.
\
\ To keep the task simple, we only allow integer less than or equal to 255.
\
\ Example
\ Input: $N = 101
\ Output: 86
\
\ Binary representation of decimal 101 is 1100101 or as 2 nibbles (0110)(0101).
\ The swapped nibbles would be (0101)(0110) same as decimal 86.
\
\ Input: $N = 18
\ Output: 33
\
\ Binary representation of decimal 18 is 10010 or as 2 nibbles (0001)(0010).
\ The swapped nibbles would be (0010)(0001) same as decimal 33.

: swap_nibbles { n -- n }
    [ HEX ]
    n 4 RSHIFT 00F AND
    n 4 LSHIFT 0F0 AND OR
    [ DECIMAL ] ;

NEXT-ARG S>NUMBER? 0= THROW DROP
swap_nibbles . CR BYE