Version: 4.0.2
3.11 Boxes
A box is like a single-element vector. It prints as #& followed by the printed form of the boxed value. A #& form can also be used as an expression, but since the resulting box is constant, it has practically no use.
Examples: |
> b |
#&"apple" |
> (unbox b) |
"apple" |
> (set-box! b '(banana boat)) |
> b |
#&(banana boat) |
Boxes in Reference: PLT Scheme provides more on boxes and box procedures.