get rid of the parse dependency?

[mathause]

We use the r1chardj0n3s/parse library to retrieve the placeholders out of the path. When I wrote this library I looked for functionality that does the inverse from f-strings and parse offered exactly this & has therefore been very helpful. It does the parsing by constructing regular expressions that are then matched against the path. However, there are 3 limitations:

1. it offers format specifiers that are not invertible

• use format specifiers to create names #91
• Think about consequences of format specifiers in patterns #154
• Addendum to the find_files and find_paths documentation: use of regular expressions #155

2. placeholders cannot be empty

• Key cannot be empty #153

3. it's not typed

• type filefisher #165

We could try to remove our dependency on parse and write out our own parsing functions/ regexes. We could also vendor and adapt it (it's under a MIT license). This could allow to overcome the issues above. We would need to think very much about which format specifiers are needed for paths.

Disadvantages:

• overall it works well the way it is now
• it would be quite some work
• a lot of thought went into the regexes - can we really do better (we might)

Alternatives:

1. restrict the allowed format specifiers
2. could allow custom types (but probably not a nice API)
3. not a real problem