Hi Pratik, You might be able to do some of required things using PatternReplaceChartFilter, but as you can see it does not operate on tokens level but input string. Your best bet is custom token filter. Not sure how familiar you are with how token filters work, but you have access to tokens from previous filter and you can implement any logic you want: you consume three tokens and emit tokens based on adjacent tokens.
HTH, Emir -- Monitoring - Log Management - Alerting - Anomaly Detection Solr & Elasticsearch Consulting Support Training - http://sematext.com/ > On 7 Feb 2020, at 19:27, Pratik Patel <pra...@semandex.net> wrote: > > Hello Everyone, > > Let's say I have an analyzer which has following token stream as an output. > > *token stream : [], a, ab, [], c, [], d, de, def .....* > > Now let's say I want to add another filter which will drop a certain tokens > based on whether adjacent token on the right side is [] or some string. > > for a given token, > drop/replace it by empty string it if there is a non-empty string > token on its right and > keep it if there is an empty token string on its right. > > based on this, the resulting token stream would be like this. > > *desired output stream : [], [a]<dropped>, ab, [], c, [], d<dropped>, > de<dropped>, def * > > > *Is there any Filter available in solr with which this can be achieved?* > *If writing a custom filter is the only possible option then I want to know > whether its possible to access adjacent tokens in the custom filter?* > > *Any idea about this would be really helpful.* > > Thanks, > Pratik
