Make --with-nth strip the last delimiter

[junegunn]

#1323 (comment)

Currently, --with-nth keeps the last trailing delimiter.

echo foo,bar,baz | fzf --delimiter , --with-nth 2,1
  # bar,foo,

This behavior is usually not desirable, but now you can work around it by using a template.

Note

When you use a template, the trailing delimiter is stripped from each expression, giving you more control over the output.

echo foo,bar,baz | fzf --delimiter , --with-nth '{2},{1}'
  # bar,foo

Should we strip the last trailing delimiter by default? It means breaking backward compatibility, but you can replicate the old behavior using templates.

# Please keep the last comma!
echo foo,bar,baz | fzf --delimiter , --with-nth '{2},{1},'
  # bar,foo,

However, when rearranging markdown table columns, keeping the last delimiter is desirable because it contains whitespaces for alignment, and you can't replicate the previous behavior using templates.

fzf --reverse --delimiter ' *\| *' --with-nth ..3 << 'EOF'
| Package Manager | Linux Distribution      | Command                            |
| --------------- | ----------------------- | ---------------------------------- |
| APK             | Alpine Linux            | `sudo apk add fzf`                 |
| APT             | Debian 9+/Ubuntu 19.10+ | `sudo apt install fzf`             |
EOF

# This doesn't work
fzf --reverse --delimiter ' *\| *' --with-nth '{..3} |' << 'EOF'
| Package Manager | Linux Distribution      | Command                            |
| --------------- | ----------------------- | ---------------------------------- |
| APK             | Alpine Linux            | `sudo apk add fzf`                 |
| APT             | Debian 9+/Ubuntu 19.10+ | `sudo apt install fzf`             |
EOF

[vimpostor]

Thanks for clearing this up. For me using the template {1} instead is an acceptable solution, and I agree with you it may do more harm if we break backwards compatibility, even if it was a better default. So maybe it's best to keep it as it is right now.

The only ugly thing is now that --with-nth and --accept-nth behave differently without templates.

[junegunn]

The only ugly thing is now that --with-nth and --accept-nth behave differently without templates.

Fair enough. The inconsistency can surprise the users. My thought was there are cases, albeit niche, where it's desirable to keep the last delimiter when using --with-nth (e.g. the table example above), but no one would want it in the context of --accept-nth.