On Tue, Jan 20, 2009 at 23:26:49 +0100, Bruno Haible wrote: > It is correct that perfect decimal to binary conversion requires an > amount of memory that is proportional to the absolute value of the > exponent, and that requires a malloc(). But strtod is allowed to fail > with ENOMEM. See POSIX:
Thanks, that makes things easier. > > What would be the benefit of allowing decimal_point to be specified, > > without supporting multi-byte decimal points or any other locale- > > specific behaviour? > > I don't think multi-byte decimal points exist. All glibc locales, at > least, have only '.' or ',' as decimal separator. Regarding locale-dependent > digits, or grouping characters, I don't know... fa_IR has a multi-byte monetary decimal point in glibc, but the regular ones are all "." or ",". That locale also prints in Arabic-Indic numerals if you use the "I" printf flag, but these numerals are rejected by strtod. strtod also rejects decimal separators, at least in da_DK (which prints them when the "'" flag is specified), so maybe these features aren't important. > > Apart from replacing '.', the code would have to filter characters that > > wouldn't be accepted in the C locale, since other locales may interpret > > them in an unexpected way. > > Yes. But this is easy preprocessing, compared to the rest of strtod. Do you want me to submit a patch that does this preprocessing? I guess decimal_point_char would need to go into a new module if localeconv isn't safe to use (and human.c would need to use it too). But could localeconv really cause a problem? Since it's not safe to change locales in a multi-threaded application, I don't see what the problem would be. > Yes, ASCII > specifies not only a set of characters but also their numeric values, > but other encodings (such as EBCDIC) are not in use among the audience of > gnulib. OK. I assumed non-ASCII encodings were supported because c-ctype.c seems to go out of its way to support them (and has the same comment about encoding in its documentation as c-strtod). -- Michael
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