This package provides extension support for simple boolean queries typically seen in literature databases.

It is forked from lang-example and https://github.com/ShreyRavi/lang-simpleboolean and shares their license.

Syntax is a simple generalization of boolean syntax seen on large literature databases like PubMed. Binary operators provided are:

• AND
• OR
• NOT

Which are given in order of precedence and may either be all lower or upper case.

To specify precedence, ( and ) may wrap any expression.

All other tokens are treated as identifiers/variables.

ketchup AND mustard

(rice and "soy sauce") 
OR 
(potatos AND cheese)