[FeatureRequest] Case-insensitive file name lexicographical orderings #258

It would be useful to have case-insensitive file name lexicographical orderings for systems where the default file system is case-insensitive (e.g., Windows).

Feel free to close this issue if not applicable and/or desirable.

Version:

erd.exe -V
erdtree 3.1.2

Lexicographical order demonstration:

erd.exe -C none -s name --dir-order last -y inverted --suppress-size ..\Test-Tree
 Test-Tree
 ├─ AbcdefB
 ├─ AbcdefZ
 ├─ abcdefa
 ├─ abcdefm
 ├─ AbcdefB.txt
 ├─ AbcdefZ.txt
 ├─ abcdefa.txt
 └─ abcdefm.txt

4 directories, 4 files

Windows cmd.exe dir command (sort by name alphabetic):

dir /b /ON ..\Test-Tree
abcdefa
abcdefa.txt
AbcdefB
AbcdefB.txt
abcdefm
abcdefm.txt
AbcdefZ
AbcdefZ.txt

Windows cmd.exe dir command (group directories first, sort by name alphabetic):

dir /b /OGN ..\Test-Tree
abcdefa
AbcdefB
abcdefm
AbcdefZ
abcdefa.txt
AbcdefB.txt
abcdefm.txt
AbcdefZ.txt

Sample options for case-insensitive lexicographical order:

• nameci: Sort entries by file name in lexicographical order (case-insensitive)
• rnameci: Sort entries by file name in reverse lexicographical order (case-insensitive)

Mock-up of example usage and output:

erd.exe -C none -s nameci --dir-order last -y inverted --suppress-size
 Test-Tree
 ├─ abcdefa
 ├─ AbcdefB
 ├─ abcdefm
 ├─ AbcdefZ
 ├─ abcdefa.txt
 ├─ AbcdefB.txt
 ├─ abcdefm.txt
 └─ AbcdefZ.txt

The directories first, and case-insensitive name sorting is typically the default in Windows File Explorer and other file managers.