Logical operators for g.search.modules

[Nikos Alexandris]

Following are ​results searching for `g.search.modules` tickets: #3624, #3583, #3405, #3341, #3149, #386, #151.

Considering these and the fact that g.search.modules features currently three flags (-a, -n and -k) to minapulate the retrieval of modules based on (combination) keywords,

what about using parameters like subset= based on pre-defined sets that list modules and/or selection= based on logical operators to combine the requested keywords?

Examples of describing the inerface:

subset Subset of available modules
       options: all, core, addons, other(?)
       default: core

or even (which might overlap the functionality of keywords=?)

subset Subset of available modules
       options: all, core, addons, generic, raster, vector, miscellaneous, temporal
       default: core

(under options also things like the topics index if topis are not covered by the keywords index ?)

and

selection Define selection of keywords
          options: and,or,not,xor,xnor,nand
          default: or

(obviously, excluding operators which would not make sense).