F1Score metric

@synalinks_export("synalinks.metrics.F1Score")
class F1Score(FBetaScore):
    """Computes F-1 Score.

    Formula:

    ```python
    f1_score = 2 * (precision * recall) / (precision + recall)
    ```

    This is the harmonic mean of precision and recall.
    Its output range is `[0, 1]`. It operates at a word level
    and can be used for **QA systems**.

    If `y_true` and `y_pred` contains multiple fields
    The JSON object's fields are flattened and the score
    computed for each one independently before being averaged.


    Example:

    ```python
    program.compile(
        metrics=[
            synalinks.metrics.F1Score(),
        ],
    )
    ```

    Args:
        average (str): Type of averaging to be performed across per-field results
            in the multi-field case.
            Acceptable values are `None`, `"micro"`, `"macro"` and
            `"weighted"`. Defaults to `None`.
            If `None`, no averaging is performed and `result()` will return
            the score for each class.
            If `"micro"`, compute metrics globally by counting the total
            true positives, false negatives and false positives.
            If `"macro"`, compute metrics for each label,
            and return their unweighted mean.
            This does not take label imbalance into account.
            If `"weighted"`, compute metrics for each label,
            and return their average weighted by support
            (the number of true instances for each label).
            This alters `"macro"` to account for label imbalance.
            It can result in an score that is not between precision and recall.
        name (str): (Optional) string name of the metric instance.
        in_mask (list): (Optional) list of keys to keep to compute the metric.
        out_mask (list): (Optional) list of keys to remove to compute the metric.
        in_mask_pattern (str): (Optional) Regex pattern; fields whose names match
            are kept (combined with ``in_mask`` via OR).
        out_mask_pattern (str): (Optional) Regex pattern; fields whose names match
            are dropped (combined with ``out_mask`` via OR).
    """

    def __init__(
        self,
        average=None,
        name="f1_score",
        in_mask=None,
        out_mask=None,
        in_mask_pattern=None,
        out_mask_pattern=None,
    ):
        super().__init__(
            average=average,
            beta=1.0,
            name=name,
            in_mask=in_mask,
            out_mask=out_mask,
            in_mask_pattern=in_mask_pattern,
            out_mask_pattern=out_mask_pattern,
        )

    def get_config(self):
        """Return the serializable config of the metric.

        Returns:
            (dict): The config dict.
        """
        base_config = super().get_config()
        del base_config["beta"]
        return base_config