Double-width characters spoil column alignment

[smammy]

Test case:

printf '%s\t%s\n' \
    sample width \
    $'\uFF21\uFF22\uFF23\uFF24\uFF25' double \
    ABCDE single \
> example.tsv
mlr --from example.tsv --t2p cat

Expected result:

Actual result:

References:

• https://en.wikipedia.org/wiki/Duospaced_font
• https://en.wikipedia.org/wiki/Halfwidth_and_fullwidth_forms
• https://git.kernel.org/pub/scm/utils/util-linux/util-linux.git/tree/text-utils/column.c
• https://man7.org/linux/man-pages/man3/wcwidth.3.html

[johnkerl]

Perhaps #379 and this would have the same fix ...

[smammy]

Perhaps #379 and this would have the same fix ...

I bet it would!

[smammy]

util-linux' column command uses wcwidth to calculate number of columns the character will use. Found StringWidth in uniseg; maybe that would be useful?

[smammy]

Specifically, here?

https://github.com/johnkerl/miller/blob/8d6455dfab557f1ba913186bae00b1d68e0dd4a7/pkg/output/record_writer_pprint.go#L108C13-L108C35