ParserEvaluator (Apache OpenNLP Tools 1.9.5 API)
Date: 2026-06-18

opennlp.tools.parser

## Class ParserEvaluator

- java.lang.Object
- - opennlp.tools.util.eval.Evaluator<Parse>
  - - opennlp.tools.parser.ParserEvaluator

-     public class ParserEvaluator
      extends Evaluator<Parse>

  Class for ParserEvaluator. This ParserEvaluator behaves like EVALB with no exceptions, e.g, without removing punctuation tags, or equality between ADVP and PRT (as in COLLINS convention). To follow parsing evaluation conventions (Bikel, Collins, Charniak, etc.) as in EVALB, options are to be added to the `ParserEvaluatorTool`.

- - ### Constructor Summary

    Constructors
    Constructor and Description
    `ParserEvaluator(Parser aParser, ParserEvaluationMonitor... monitors)` Construct a parser with some evaluation monitors.

  - ### Method Summary

    All Methods Instance Methods Concrete Methods
    Modifier and Type | Method and Description
    --- | ---
    `FMeasure` | `getFMeasure()` It returns the fmeasure result.

    - ### Methods inherited from class opennlp.tools.util.eval.Evaluator

      `evaluate, evaluateSample`

    - ### Methods inherited from class java.lang.Object

      `equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- - ### Constructor Detail

    - #### ParserEvaluator

          public ParserEvaluator(Parser aParser,
                                 ParserEvaluationMonitor... monitors)

      Construct a parser with some evaluation monitors.
      Parameters:
        `aParser` -
        `monitors` - the evaluation monitors

  - ### Method Detail

    - #### getFMeasure

          public final FMeasure getFMeasure()

      It returns the fmeasure result.
      Returns:
        the fmeasure value

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