org.apache.lucene.search.highlight

## Interface Scorer

All Known Implementing Classes:
  QueryScorer, QueryTermScorer

    public interface Scorer

A Scorer is responsible for scoring a stream of tokens. These token scores can then be used to compute `TextFragment` scores.

### Method Summary

All Methods Instance Methods Abstract Methods
`float` `getFragmentScore()` Called when the `Highlighter` has no more tokens for the current fragment - the Scorer returns the weighting it has derived for the most recent fragment, typically based on the results of `getTokenScore()`.
`float` `getTokenScore()` Called for each token in the current fragment.
`TokenStream` `init(TokenStream tokenStream)` Called to init the Scorer with a `TokenStream`.
`void` `startFragment(TextFragment newFragment)` Called when a new fragment is started for consideration.

### Method Detail

#### init

    TokenStream init(TokenStream tokenStream)
              throws IOException

Called to init the Scorer with a `TokenStream`. You can grab references to the attributes you are interested in here and access them from `getTokenScore()`.

Parameters:
  `tokenStream` - the `TokenStream` that will be scored.
Returns:
  either a `TokenStream` that the Highlighter should continue using (eg if you read the tokenSream in this method) or null to continue using the same `TokenStream` that was passed in.
Throws:
  `IOException` - If there is a low-level I/O error

#### startFragment

    void startFragment(TextFragment newFragment)

Called when a new fragment is started for consideration.

Parameters:
  `newFragment` - the fragment that will be scored next

#### getTokenScore

    float getTokenScore()

Called for each token in the current fragment. The `Highlighter` will increment the `TokenStream` passed to init on every call.

Returns:
  a score which is passed to the `Highlighter` class to influence the mark-up of the text (this return value is NOT used to score the fragment)

#### getFragmentScore

    float getFragmentScore()

Called when the `Highlighter` has no more tokens for the current fragment - the Scorer returns the weighting it has derived for the most recent fragment, typically based on the results of `getTokenScore()`.