encoding/csv: Classic Mac (CR) line delimiters not supported

[gopherbot]

by olegs.denisovs:

Windows (CRLF) and Unix (LF) line delimiters work fine, but if I try to read csv file
with Classic Mac (CR) line delimiters then it works incorrectly.

[bradfitz]

Comment 1:

I think you'll find most of the standard library won't deal with Classic Mac (CR) files.
You'll probably want to write your io.Readers with a CR-to-CRLF io.Reader.

[gopherbot]

Comment 2 by MattieuGA:

FWIW, The current version of Excel on the current version of Mac OSX uses CR as a line
delimiter. It's not uncommon to have those files hit your server if your are allowing
user generated content.

[ianlancetaylor]

Comment 3:

The package operates as documented.  There is a workaround.  I'm not sure what we can do
here at this point.

Status changed to Unfortunate.

[bdaglish]

FWIW, I seem to have fixed it by changing readRune in reader.go to do this..

if r1 == '\r' {
    r1, _, err = r.r.ReadRune()
    if err == nil  && r1 != '\n' {
        r.r.UnreadRune()
    }
    r1='\n'
}

Shall I submit a patch?

[bradfitz]

No, we're not going to modify things ad hoc to support Classic Mac OS line endings. Consider the encoding/csv package effectively frozen.

[dominikh]

Writing your own io.Reader that does whatever modification is necessary is fairly straightforward and the right solution for dealing with non-standard input. Changing encoding/csv is not.

[mdwhatcott]

In my work I see a lot of classic mac os line endings so a patch would be a very welcome addition. Looks like I'm going to Implement a reader to adapt '\r' to '\n'.

[ctessum]

In case anyone ends up here in the future, there is an implementation of the workaround described above here: https://godoc.org/github.com/ctessum/macreader