egcs, casting the argument of eg isalpha to an int...

[Lassi A. Tuura]

Kaveh R. Ghazi wrote:
|> I'm thinking of changing them to this:
|> 
|>  > #define ISALPHA(c) (IN_CTYPE_DOMAIN (c) && isalpha (((int)(c))))
|> 
|> This would seem to avoid the warning.
|> 
|> 	Is this solution correct from a technical standpoint?

Often characters must be casted to `unsigned char' before being used
with is* functions.  The reason is that the functions require the
argument to be an int with non-negative or EOF value.  If you pass in a
char and chars are signed, a character with the high bit set receives
incorrect treatment (sign extension). Thus, if you got the character by
scanning a string, convert it to `unsigned char' first to make sure this
does not happen.  If you got it from fgetc, no conversion is necessary
-- but you must make sure you use int in the first place, and not
convert the returned value to char. 

//lat
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Lassi.Tuura@cern.ch          There's no sunrise without a night