Re: Unicode numeric value

[John Cowan <cowan@ccil.org>]

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I can't help (yet) if you need the full numeric value.  But if the decimal
digit value is enough for you, then the attached source file should work
(from Chibi).

On Sat, Dec 15, 2018 at 11:32 PM Freeman Gilmore <freeman.gilmore@gmail.com>
wrote:

> I am looking for a procedure that will read the numeric value, field 8, of
> an Unicode numeric character.   Has anyone written this procedure or know
> where I can find it?
>
> Thank you,
>
> ƒg
>

[-- Attachment #2: digit-value.scm --]
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(cond-expand
 (full-unicode
  (define zeros
    '#(#\x0030                ;DIGIT ZERO
       #\x0660                ;ARABIC-INDIC DIGIT ZERO
       #\x06F0                ;EXTENDED ARABIC-INDIC DIGIT ZERO
       #\x07C0                ;NKO DIGIT ZERO
       #\x0966                ;DEVANAGARI DIGIT ZERO
       #\x09E6                ;BENGALI DIGIT ZERO
       #\x0A66                ;GURMUKHI DIGIT ZERO
       #\x0AE6                ;GUJARATI DIGIT ZERO
       #\x0B66                ;ORIYA DIGIT ZERO
       #\x0BE6                ;TAMIL DIGIT ZERO
       #\x0C66                ;TELUGU DIGIT ZERO
       #\x0CE6                ;KANNADA DIGIT ZERO
       #\x0D66                ;MALAYALAM DIGIT ZERO
       #\x0E50                ;THAI DIGIT ZERO
       #\x0ED0                ;LAO DIGIT ZERO
       #\x0F20                ;TIBETAN DIGIT ZERO
       #\x1040                ;MYANMAR DIGIT ZERO
       #\x1090                ;MYANMAR SHAN DIGIT ZERO
       #\x17E0                ;KHMER DIGIT ZERO
       #\x1810                ;MONGOLIAN DIGIT ZERO
       #\x1946                ;LIMBU DIGIT ZERO
       #\x19D0                ;NEW TAI LUE DIGIT ZERO
       #\x1A80                ;TAI THAM HORA DIGIT ZERO
       #\x1A90                ;TAI THAM THAM DIGIT ZERO
       #\x1B50                ;BALINESE DIGIT ZERO
       #\x1BB0                ;SUNDANESE DIGIT ZERO
       #\x1C40                ;LEPCHA DIGIT ZERO
       #\x1C50                ;OL CHIKI DIGIT ZERO
       #\xA620                ;VAI DIGIT ZERO
       #\xA8D0                ;SAURASHTRA DIGIT ZERO
       #\xA900                ;KAYAH LI DIGIT ZERO
       #\xA9D0                ;JAVANESE DIGIT ZERO
       #\xAA50                ;CHAM DIGIT ZERO
       #\xABF0                ;MEETEI MAYEK DIGIT ZERO
       #\xFF10                ;FULLWIDTH DIGIT ZERO
       #\x104A0               ;OSMANYA DIGIT ZERO
       #\x11066               ;BRAHMI DIGIT ZERO
       #\x1D7CE               ;MATHEMATICAL BOLD DIGIT ZERO
       #\x1D7D8               ;MATHEMATICAL DOUBLE-STRUCK DIGIT ZERO
       #\x1D7E2               ;MATHEMATICAL SANS-SERIF DIGIT ZERO
       #\x1D7EC               ;MATHEMATICAL SANS-SERIF BOLD DIGIT ZERO
       #\x1D7F6               ;MATHEMATICAL MONOSPACE DIGIT ZERO
       )))
 (else
  (define zeros #(#\0))))

(define (digit-value ch)
  (let ((n (char->integer ch)))
    (let lp ((lo 0) (hi (- (vector-length zeros) 1)))
      (if (> lo hi)
          #f
          (let* ((mid (+ lo (quotient (- hi lo) 2)))
                 (mid-zero (char->integer (vector-ref zeros mid))))
            (cond
             ((<= mid-zero n (+ mid-zero 9))
              (- n mid-zero))
             ((< n mid-zero)
              (lp lo (- mid 1)))
             (else
              (lp (+ mid 1) hi))))))))