Price fraction: Difference between revisions

=={{header|Forth}}==

A floating-point version wouldn't be hard -- four words would change ( , @ @ cell+ -to- f, f@ f@ float+ ), EVALUATE would be replaced with a small word that forced a floating-point interpretation, and the return stack would not be used in ROUND -- but it would be strikingly unusual. See this page's discussion.

<lang>: as begin parse-word dup while evaluate , repeat 2drop ;

create bounds as 96 91 86 81 76 71 66 61 56 51 46 41 36 31 26 21 16 11 6 0

create official as 100 98 94 90 86 82 78 74 70 66 62 58 54 50 44 38 32 26 18 10

: official@ ( a-bounds -- +n )

\ (a+n) - a + b = (a+n) + (b - a) = (b+n)

[ official bounds - literal ] + @ ;

: round ( n-cents -- n-cents' )

>r bounds begin dup @ r@ > while cell+ repeat

r> drop official@ ;</lang>