Re: Support for boolean queries in apropos

[Alan Barrett <apb%cequrux.com@localhost>]

On Sun, 11 Mar 2012, Abhinav Upadhyay wrote:
> The FTS engine of Sqlite supports Boolean queries. Boolean 
> queries simply means building complex queries by combining 
> simple queries using Boolean operators: AND, OR, and NOT. For 
> example:
>
> $ apropos add new user NOT (git OR ssh)
>
> This will provide results which match the query "add new user" 
> but do not match for "git" or "ssh".

Instead of exposing the underlying syntax of the SQL engine, 
I would prefer to see a user interface syntax similar to that 
ptovided by google search.

        $ apropos 'add "new user" -(git|ssh)'
        $ apropos add '"new user"' '-(git|ssh)'

where the outer quotes are for the shell, the inner quotes around 
"new user" mean that those two words must appear together, the "-" 
means the following term must not appear, the "|" means OR, and 
the parentheses are for scoping.  Not shown in the example is the 
"+" operator, which google search uses to mean that the term must 
appear, or that the term has a higher weight than other terms in 
determining the overall ranking of the results.

> 2. Or, another option is to use '||', '&&' and '~' as the 
> symbols for the OR, AND, NOT Boolean operators respectively 
> in the apropos frontend and pre-process it to build a proper 
> SQL query so that Sqlite is able to understand and execute it 
> properly.

Please don't make users learn new syntax.  I expect many users 
will already familiar with the syntax offered by google search, so 
I think it's a good idea to re-use that syntax.

--apb (Alan Barrett)