private BaseDescr lhsAnd()

in drools-drl/drools-drl-parser/src/main/java/org/drools/drl/parser/lang/DRL6Parser.java [2272:2407]
122 lines of code
29 McCabe index (conditional complexity)

    private BaseDescr lhsAnd(final CEDescrBuilder<?, ?> ce,
            boolean allowOr) throws RecognitionException {
        BaseDescr result = null;
        if (input.LA(1) == DRL6Lexer.LEFT_PAREN && helper.validateLT(2,
                DroolsSoftKeywords.AND)) {
            // prefixed AND
            CEDescrBuilder<?, AndDescr> and = null;
            if (state.backtracking == 0) {
                and = ce.and();
                result = ce.getDescr();
                helper.start(and,
                        CEDescrBuilder.class,
                        null);
            }
            try {
                match(input,
                        DRL6Lexer.LEFT_PAREN,
                        null,
                        null,
                        DroolsEditorType.SYMBOL);
                if (state.failed)
                    return null;

                match(input,
                        DRL6Lexer.ID,
                        DroolsSoftKeywords.AND,
                        null,
                        DroolsEditorType.KEYWORD);
                if (state.failed)
                    return null;

                while (input.LA(1) == DRL6Lexer.AT) {
                    // annotation*
                    annotation(and);
                    helper.logAnnotationInLhsPatternWarn(and);
                    if (state.failed)
                        return null;
                }

                if (state.backtracking == 0) {
                    helper.emit(Location.LOCATION_LHS_BEGIN_OF_CONDITION_AND_OR);
                }
                while (input.LA(1) != DRL6Lexer.RIGHT_PAREN) {
                    lhsUnary(and,
                            allowOr);
                    if (state.failed)
                        return null;
                }

                match(input,
                        DRL6Lexer.RIGHT_PAREN,
                        null,
                        null,
                        DroolsEditorType.SYMBOL);
                if (state.failed)
                    return null;
            } finally {
                if (state.backtracking == 0) {
                    helper.end(CEDescrBuilder.class,
                            and);
                }
            }
        } else {
            // infix AND

            // create an AND anyway, since if it is not an AND we remove it later
            CEDescrBuilder<?, AndDescr> and = null;
            if (state.backtracking == 0) {
                and = ce.and();
                result = and.getDescr();
                helper.start(and,
                        CEDescrBuilder.class,
                        null);
            }
            try {
                lhsUnary(and,
                        allowOr);
                if (state.failed)
                    return null;

                if (helper.validateIdentifierKey(DroolsSoftKeywords.AND) ||
                        input.LA(1) == DRL6Lexer.DOUBLE_AMPER) {
                    while (helper.validateIdentifierKey(DroolsSoftKeywords.AND) ||
                            input.LA(1) == DRL6Lexer.DOUBLE_AMPER) {
                        if (input.LA(1) == DRL6Lexer.DOUBLE_AMPER) {
                            match(input,
                                    DRL6Lexer.DOUBLE_AMPER,
                                    null,
                                    null,
                                    DroolsEditorType.SYMBOL);
                            helper.logInfixAndWarn(and);
                        } else {
                            match(input,
                                    DRL6Lexer.ID,
                                    DroolsSoftKeywords.AND,
                                    null,
                                    DroolsEditorType.KEYWORD);
                        }
                        if (state.failed)
                            return null;

                        while (input.LA(1) == DRL6Lexer.AT) {
                            // annotation*
                            annotation(and);
                            helper.logAnnotationInLhsPatternWarn(and);
                            if (state.failed)
                                return null;
                        }

                        if (state.backtracking == 0) {
                            helper.emit(Location.LOCATION_LHS_BEGIN_OF_CONDITION_AND_OR);
                        }
                        lhsUnary(and,
                                allowOr);
                        if (state.failed)
                            return null;
                    }
                } else {
                    if (state.backtracking == 0 && and.getDescr().getDescrs().size() < 2) {
                        // if no AND present, then remove it and add children to parent
                        ((ConditionalElementDescr) ce.getDescr()).getDescrs().remove(and.getDescr());
                        for (BaseDescr base : and.getDescr().getDescrs()) {
                            ((ConditionalElementDescr) ce.getDescr()).addDescr(base);
                        }
                        result = ce.getDescr();
                    }
                }
            } finally {
                if (state.backtracking == 0) {
                    helper.end(CEDescrBuilder.class,
                            and);
                }
            }
        }
        return result;
    }