o
    yi|                     @   s`   d dl mZmZmZ d dlZd dlmZmZ d dlmZ d dl	m
Z
mZmZ G dd deZdS )    )AnyOptionalSequenceN)Tensortensor)Metric)_bleu_score_compute_bleu_score_update_tokenize_fnc                	       s   e Zd ZU dZdZeed< dZeed< dZeed< e	ed< e	ed< e	ed	< e	ed
< 			dde
dedeee  def fddZdee deee  ddfddZde	fddZ  ZS )	BLEUScorea  Calculate `BLEU score`_ of machine translated text with one or more references.

    As input to ``forward`` and ``update`` the metric accepts the following input:

    - ``preds`` (:class:`~Sequence`): An iterable of machine translated corpus
    - ``target`` (:class:`~Sequence`): An iterable of iterables of reference corpus

    As output of ``forward`` and ``update`` the metric returns the following output:

    - ``bleu`` (:class:`~torch.Tensor`): A tensor with the BLEU Score

    Args:
        n_gram: Gram value ranged from 1 to 4
        smooth: Whether or not to apply smoothing, see `Machine Translation Evolution`_
        kwargs: Additional keyword arguments, see :ref:`Metric kwargs` for more info.
        weights:
            Weights used for unigrams, bigrams, etc. to calculate BLEU score.
            If not provided, uniform weights are used.

    Raises:
        ValueError: If a length of a list of weights is not ``None`` and not equal to ``n_gram``.

    Example:
        >>> from torchmetrics import BLEUScore
        >>> preds = ['the cat is on the mat']
        >>> target = [['there is a cat on the mat', 'a cat is on the mat']]
        >>> bleu = BLEUScore()
        >>> bleu(preds, target)
        tensor(0.7598)
    Fis_differentiableThigher_is_betterfull_state_update	preds_len
target_len	numeratordenominator   Nn_gramsmoothweightskwargsc                    s   t  jdi | || _|| _|d ur%t||kr%tdt| d| |d ur+|nd| g| | _| jdtddd | jdtddd | jd	t	
| jdd | jd
t	
| jdd d S )Nz5List of weights has different weights than `n_gram`: z != g      ?r   g        sum)dist_reduce_fxr   r   r    )super__init__r   r   len
ValueErrorr   	add_stater   torchzeros)selfr   r   r   r   	__class__r   J/home/ubuntu/.local/lib/python3.10/site-packages/torchmetrics/text/bleu.pyr   E   s   zBLEUScore.__init__predstargetreturnc              	   C   s,   t ||| j| j| j| j| jt\| _| _dS )z*Update state with predictions and targets.N)r	   r   r   r   r   r   r
   )r"   r&   r'   r   r   r%   updateX   s   zBLEUScore.updatec                 C   s"   t | j| j| j| j| j| j| jS )zCalculate BLEU score.)r   r   r   r   r   r   r   r   )r"   r   r   r%   computee   s   zBLEUScore.compute)r   FN)__name__
__module____qualname____doc__r   bool__annotations__r   r   r   intr   r   floatr   r   strr)   r*   __classcell__r   r   r#   r%   r      s.   
 
"r   )typingr   r   r   r    r   r   torchmetricsr   !torchmetrics.functional.text.bleur   r	   r
   r   r   r   r   r%   <module>   s   