Shiro Kawai scripsit: > (1) Define char-numeric? returns #t if the character's Numeric_Type > property value is other than 'None'.
AFAICT no Scheme supports this definition. > (2) Drop char-numeric?, and add char-numeric-type and > char-numeric-value. The former returns the value of Numeric_Type > property, and the latter returns the value of Numeric_Value property. > This should be the way to provide access to a character's Unicode > "Numeric" property. Dropping an IEEE Scheme procedure is out of scope. > (3) Define char-numeric? to return #t only for 0,1,2,3,4,5,6,7,8 and > 9. This retains the compatibility to R5RS, and we can still use > char-numeric? to parse numbers, and safely use (- (char->integer > c) (char->integer #\0)) to obtain the digit value the character > represents. (Note: R5RS programs that use char-numeric? to parse > numbers will break if we adopt the current draft's definition of > char-numeric?). Gauche, Gambit, and Chicken (without the utf8 egg) work like this. (4) Define char-numeric? to return #t for decimal digits only (general category value of Nd). Guile 2.0, Kawa, Larceny, Ypsilon, Mosh, and IronScheme work like this. (5) define char-numeric? as equivalent to the Number property (general category value of Nd, Nl, No). Scheme48, Chez, and Ikarus work like this. -- He played King Lear as though John Cowan <[email protected]> someone had played the ace. http://www.ccil.org/~cowan --Eugene Field _______________________________________________ Scheme-reports mailing list [email protected] http://lists.scheme-reports.org/cgi-bin/mailman/listinfo/scheme-reports
