blackfriday | Blackfriday: a markdown processor for Go

The gist of this error is that the version of binary used to generate the code isn't compatible with the current version of code. A quick and easy solution would be to try updating the protoc-gen-go compiler and the gRPC library to the latest version.

go get -u github.com/golang/protobuf/protoc-gen-go

then regen the proto

heres a link to a reddit thread that discusses the issue

There are at least two problems with your code.

1. A precondition of ricercaBinaria is that the underlying data array is ordered. You are using unordered data in your test
2. ricercaBinaria will return the index in which a given argument (Double) is located in your array. If it is not found, then -1 will be returned. As such, you need to check the returned index to verify that it is indeed positive before using it as an index array - otherwise the method will fail with the exception you are seeing
3. Beware of Double equality but that is for another question.

If I understand correctly, you want a particular field for all your matching docs(426 in your example), while keeping the size as 40, if this is the case, then its not possible.

total means the total number of documents in your index, matching the query while size is used to return the top based on size documents(based on the score) in your index.

You can use the source filtering or retrieved particular field in the search response, but you have to give a high value of size param(default is 10 for performance reasons).