Change tag filter to be partial matching instead of exact

[KaelenProctor]

Problem

The tag filter with a string value is doing exact matching, which is less useful that a partial match and if you compare it to name filtering the : operation is for partial not exact matching.

Because the tag filter supports both strings (the tag value matches the string) and numbers (the count of tags) it is not really possible to support both = and : for strings, as that would cause ambiguity in the parser given that all numbers are a subset of a string.

Solution

Update setElementOperation so that the : operator does partial matching of the set element value.

Though setElementOperation is also used in the various legality filters (legality, banned, restricted and variants), the change for : to partial match doesn't affect it because the grammar defines all the possible formats as full strings. Thus even though setElementOperation will be doing a partial match, its equivalent to an exact match given that only the exact format strings are allowed.

Testing

Before

It can match tags that are a single word (no spaces) without quotes:

But if the tag has a space, double quotes are required (otherwise the filter used is tag:word AND name contains word2)

And per the above examples, Tag filter string only does exact matching so "Spell" doesn't match the tags with "Spells matter"

After

Now tag does partial match:

Even with quotes for multiple words:

Numeric matching still works:

[haganbmj]

I'll raise the counterpoint to this PR in that partial matches renders me unable to (individually) filter for certain tags.

I use the tags signed and unsigned, which now means that tag:signed returns both and I need to construct a set of exclusions instead (eg. tag:signed -tag:unsigned) because there isn't an option for performing exact matches.

[KaelenProctor]

I'll raise the counterpoint to this PR in that partial matches renders me unable to (individually) filter for certain tags.

I use the tags signed and unsigned, which now means that tag:signed returns both and I need to construct a set of exclusions instead (eg. tag:signed -tag:unsigned) because there isn't an option for performing exact matches.

Thanks for the feedback. To support both cases my initial thought is to change tags:"<phrase>" back to exact match, as that also aligns better with how name filtering works. Per the examples on https://cubecobra.com/filters:

• goblin blood = cards whose names contain both "blood" and "goblin".
• "goblin blood" = cards whose names contain exactly "goblin blood".

@dekkerglen Does that sound reasonable to you, or any other ideas?