Ghci tab-completion cannot handle Unicode

[desegnis]

Ghci on *nix is capable of handling input Unicode identifiers encoded as UTF-8:

Prelude> let ŝaŭmmanĝaĵo = "hmmm..."
Prelude> let identifier_α = ()
Prelude> let test_π = 1
Prelude> let test_ρ = 2
Prelude> ŝaŭmmanĝaĵo
"hmmm..."

However, there is no working tab completion for those identifiers:

Prelude> ŝa<TAB><TAB><TAB>    -- Nothing happens
Prelude> identifier_�         -- Tab-completed garbage
Prelude> test_<TAB>           -- Unreadable alternatives

Since code input is interpreted as UTF-8, tab-completion output should be converted to UTF-8, too.

[igloo]

Thanks for the report!

[judah]

This will be fixed once we implement #2812 (use haskeline in ghci). The example repo mentioned in that ticket (ghci-haskeline) does not have this issue.

[cmcq]

See #2812. Those Unicode examples work for me in 6.10.3.