personList[name = "John"]

private void evaluateExpressionInContext(EvaluationContext ctx, List results, Object v) {
        try {
            ctx.enterFrame();
            // handle it as a predicate
            ctx.setValue( "item", v );
            // if it is a Map, need to add all string keys as variables in the context
            if( v instanceof Map ) {
                Set<Map.Entry> set = ((Map) v).entrySet();
                for( Map.Entry ce : set ) {
                    if( ce.getKey() instanceof String ) {
                        ctx.setValue( (String) ce.getKey(), ce.getValue() );
                    }
                }
            }

            Object r = this.filter.evaluate( ctx );
            if( r instanceof Boolean && ((Boolean)r) == Boolean.TRUE ) {
                results.add( v );
            }
        } finally {
            ctx.exitFrame();
        }
    }