Atomspec matching issues

Outline of what Chimera 1 has in order to spur discussion as to what we want ChimeraX to have.

Wildcards

*

global
Matches all atoms in a residue or all residues in a model. It stands alone as a symbol, that is, it cannot be used to match parts of names, such as G* or *A. Examples: #1:12@*, #0,1,2:50-*@CA

=

partial
Matches parts of atom or residue names but not parts of residue sequence numbers. Example: @S=

?

single character
Matches single characters within residue or atom names but not single digits within residue sequence numbers. Examples: #2:G??, :fmn@?1, #0@H@H?@H??

In attribute tests, using '~' instead of '=' indicates that the right side should be treated as a regular expression instead of a string.

Tom Goddard has implemented '*' within ChimeraX as a glob, e.g. sel ::asym_detail=*11 selects every residue with attribute asym_details (custom attribute made by IHM reader) value that ends in “11”.

Case sensitivity

Comes into play for attribute value tests (atom/residue name tests already case insensitive, and chain ID tests "partially" case insensitive). Attribute names always case sensitive. In Chimera1, attribute values are case insensitive if the test is '=' but case sensitive if the test is '=='.