private BaseDescr lhsGroupBy()

in drools-drl/drools-drl-parser/src/main/java/org/drools/drl/parser/lang/DRL6Parser.java [3321:3467]
128 lines of code
26 McCabe index (conditional complexity)

    private BaseDescr lhsGroupBy(PatternContainerDescrBuilder<?, ?> ce) throws RecognitionException {
        PatternDescrBuilder<?> pattern;
        BaseDescr result = null;

        pattern = helper.start((DescrBuilder<?, ?>) ce,
                PatternDescrBuilder.class,
                null);
        if (pattern != null) {
            result = pattern.getDescr();
        }

        try {
            if (state.backtracking == 0) {
                pattern.type("Object");
                pattern.isQuery(false);
                // might have to add the implicit bindings as well
            }

            GroupByDescrBuilder<?> groupBy = helper.start(pattern,
                    GroupByDescrBuilder.class,
                    null);
            try {
                if (helper.validateIdentifierKey(DroolsSoftKeywords.GROUPBY)) {
                    match(input,
                            DRL6Lexer.ID,
                            DroolsSoftKeywords.GROUPBY,
                            null,
                            DroolsEditorType.KEYWORD);
                }
                if (state.failed)
                    return null;

                if (state.backtracking == 0 && input.LA(1) != DRL6Lexer.EOF) {
                    helper.emit(Location.LOCATION_LHS_FROM_ACCUMULATE);
                }
                match(input,
                        DRL6Lexer.LEFT_PAREN,
                        null,
                        null,
                        DroolsEditorType.SYMBOL);
                if (state.failed)
                    return null;

                CEDescrBuilder<?, AndDescr> source = groupBy.source();
                try {
                    helper.start(source,
                            CEDescrBuilder.class,
                            null);
                    lhsAnd(source,
                            true);
                    if (state.failed)
                        return null;

                    if (source.getDescr() != null && source.getDescr() instanceof ConditionalElementDescr) {
                        ConditionalElementDescr root = source.getDescr();
                        BaseDescr[] descrs = root.getDescrs().toArray(new BaseDescr[root.getDescrs().size()]);
                        root.getDescrs().clear();
                        for (int i = 0; i < descrs.length; i++) {
                            root.addOrMerge(descrs[i]);
                        }
                    }

                } finally {
                    helper.end(CEDescrBuilder.class,
                            source);
                }

                if (input.LA(1) == DRL6Lexer.COMMA) {
                    match(input,
                            DRL6Lexer.COMMA,
                            null,
                            null,
                            DroolsEditorType.SYMBOL);
                    if (state.failed)
                        return null;
                } else if (input.LA(-1) != DRL6Lexer.SEMICOLON) {
                    // lhsUnary will consume an optional SEMICOLON, so we need to check if it was consumed already
                    // or if we must fail consuming it now
                    match(input,
                            DRL6Lexer.SEMICOLON,
                            null,
                            null,
                            DroolsEditorType.SYMBOL);
                    if (state.failed)
                        return null;
                }

                // grouping functions
                groupByKeyFunction(groupBy);
                if (state.failed)
                    return null;

                match(input,
                        DRL6Lexer.SEMICOLON,
                        null,
                        null,
                        DroolsEditorType.SYMBOL);
                if (state.failed)
                    return null;

                // accumulate functions
                accumulateFunctionBinding(groupBy);
                while (input.LA(1) == DRL6Lexer.COMMA) {
                    match(input,
                            DRL6Lexer.COMMA,
                            null,
                            null,
                            DroolsEditorType.SYMBOL);
                    if (state.failed)
                        return null;

                    accumulateFunctionBinding(groupBy);
                    if (state.failed)
                        return null;
                }

                if (input.LA(1) == DRL6Lexer.SEMICOLON) {
                    match(input,
                            DRL6Lexer.SEMICOLON,
                            null,
                            null,
                            DroolsEditorType.SYMBOL);
                    if (state.failed)
                        return null;

                    constraints(pattern);
                }
                match(input,
                        DRL6Lexer.RIGHT_PAREN,
                        null,
                        null,
                        DroolsEditorType.SYMBOL);
                if (state.failed)
                    return null;
            } finally {
                helper.end(GroupByDescrBuilder.class,
                           groupBy);
                if (state.backtracking == 0 && input.LA(1) != DRL6Lexer.EOF) {
                    helper.emit(Location.LOCATION_LHS_BEGIN_OF_CONDITION);
                }
            }
        } finally {
            helper.end(PatternDescrBuilder.class,
                    pattern);
        }
            return result;
    }