boolean_grammar.treetop

grammar BooleanGrammar
rule andable
orable '&' andable {
    def value(&block)
      orable.value(&block) && andable.value(&block)
    end
    }
    / orable
end

rule orable
notable '|' orable {
    def value(&block)
      notable.value(&block) || orable.value(&block)
    end
    } / notable
end

rule notable
[ \t]* '!' primary {
    def value(&block)
      !primary.value(&block)
    end
    } / primary
end


rule primary
[ \t]* '(' [ \t]* andable [ \t]* ')' [ \t]* {
    def value(&block)
      andable.value(&block)
    end
    } / word
end

rule word
[ \t]* [0-9a-zA-Z]+ [ \t]* {
    def value(&block)
      block.call(text_value.strip)
    end
    }
end
end