Talk:Farey sequence

REXX program encoding

What language encoding should the file be saved in, and what should the LC_* env vars be before invoking Regina on a Unixy OS? Currently under UTF-8 everything, Regina (-v: REXX-Regina_3.6(MT) 5.00 31 Dec 2011) complains:

    10 +++    say center('Farey sequence for order '   n   " has"   #   'fractions.', 150, '═')
Error 40 running "/tmp/test.rex", line 10: Incorrect call to routine
Error 40.23: CENTER argument 3 must be a single character; found "═"

It goes away after changing that "═" to any ASCII char. The same problem is present in many Rexx examples on this site. --Ledrug (talk) 21:30, 1 April 2014 (UTC)

I suspect the mechanism that is being used in saving (or downloading) the REXX program (file) from Rosetta Code is storing the character(s) of the extended ASCII (ASCII-8) as some flavor of Unicode, which Regina REXX is seeing as a two- or three-byte character. The extended-ASCII character that was being used is the 'cd'x (═) character (the horizontal double-line boxing character) from the Microsoft (DOS) code page 437 (which, I think, is probably the default code page in the USA). What you are showing (in the line with 10 +++ message) looks like a one-character (the 3^rd argument for the center BUF), but the REXX program source file probably has a two-character field stored there, thereby incurring Regina REXX's wrath (as witnessed by it issuing the error message(s). -- Gerard Schildberger (talk) 23:44, 1 April 2014 (UTC)

To address the 1^st question: all Classic REXXes that I know of only support bytes, not Unicode characters. I'm not very familiar with Unixy thingys, so I don't know what can be specified (if anything) for Regina REXX regarding this issue. As far as I know, there's nothing as far as REXX switches or environmental variables that will "fix" the above-mentioned problem; the only fix is to put in a single-byte character (which that 3^rd argument is just essentially used for fodder for a line separator, a dash would work as well, ··· or a minus sign will do in a pinch --- but then it looks chintzy, and we can't have that.) -- Gerard Schildberger (talk) 23:44, 1 April 2014 (UTC)