Support string pattern matching

[cedricduriau]

Support string pattern matching as matte selection mode.

Nuke Python Implementation

The Python implementation of Cryptomatte implemented this feature through the builtin POSIX fnmatch library. See documentation here.

Fusion Lua Implementation Research

Sadly the Lua standard library does not include POSIX support. It does ship with a builtin pattern matching syntax. See documentation here and tutorial here.

There is an external Lua module available for POSIX support. See repository here.

Comparison

Using string.gmatch

Pros:

• ships with standard Lua, no extra dependency

Cons:

• only as powerful as Lua pattern matching feature & syntax
• not consistent with Python Nuke implementation

Using posix.fnmatch

Pros:

• consistent with Python Nuke implementation

Cons:

• extra dependency

Links

• Lua pattern syntax: https://www.lua.org/pil/20.2.html
• Lua pattern tutorial: http://lua-users.org/wiki/StringLibraryTutorial
• Lua POSIX library: https://github.com/luaposix/luaposix/