No generalized form or LIKE and NOT LIKE

[TrangOul]

The only LIKE and NOT LIKE conditions possible to be constructed with this framework are:

    Field__c LIKE '%x%' /* likeAnyBoth */
    Field__c LIKE '%x'  /* likeAnyLeft */
    Field__c LIKE  'x%' /* likeAnyRight */
NOT Field__c LIKE '%x%' /* notLikeAnyBoth */

These are the most common usages of LIKE, but not the only ones.
While it is possible to write, say, LIKE '%x_y%z' by using likeAnyLeft('x_y%z'), there seems to be no way to write queries without % at one of the ends, like:

WHERE Email LIKE 'forename%.com'