2010/8/11 Horace Dynamite <horace.dynam...@gmail.com>
> # And now the the thing I can't figure out how to do, the programmer
> creates a 2d hash, retaining the "values" column.
> %CODE = ( A => { map { $CODE_CHARS{A}[$_] => $_ } 0..106 },
> B => { map { $CODE_CHARS{B}[$_] => $_ } 0..106 },
> C => { map { $CODE_CHARS{C}[$_] => $_ } 0..106 } );
>
Are you asking how to retain the index (i.e. the $_, what you called
"values") along with the encodings? The amount of Perl code you showed did
not do that (it just retains $_ without the encoding).
Assuming you want to retain both the encoding and value "together", a
*cons*will do:
(define (.. lower higher) ;; shorthand for perl's N..M generator syntax
(build-list (- (+ higher 1) lower) (lambda (n) (+ n lower))))
(define A
(make-hash (map (lambda (value)
(cons (list-ref 128-A value) ;; key
;; encoding + value
*(cons (list-ref ENCODING n) value)*))
(.. 0 106))))
;; (define B ...)
;; (define C ...)
Then you just refer to the values...
(define (encoding-ref hash key)
(*car* (hash-ref hash key)))
(define (value-ref hash key)
(*cdr* (hash-ref hash key)))
Then you have
> (encoding-ref A #\G)
11010001000
> (value-ref A #\G)
39
Hope this is what you are looking for.
Cheers,
yc
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