docs: def diff(a, b, segmenter=None):
      """
      Performs a diff comparison between two sequences of tokens (`a` and `b`)
      using `segmenter` to cluster and match
      :class:`deltas.MatchableSegment`.
  
      :Example:
          >>> from deltas import segment_matcher, text_split
          >>>
          >>> a = text_split.tokenize("This is some text.  This is some other text.")
          >>> b = text_split.tokenize("This is some other text.  This is some text.")
          >>> operations = segment_matcher.diff(a, b)
          >>>
          >>> for op in operations:
          ...     print(op.name, repr(''.join(a[op.a1:op.a2])),
          ...           repr(''.join(b[op.b1:op.b2])))
          ...
          equal 'This is some other text.' 'This is some other text.'
          insert '' '  '
          equal 'This is some text.' 'This is some text.'
          delete '  ' ''
  
      :Parameters:
          a : `list`(:class:`deltas.tokenizers.Token`)
              Initial sequence
          b : `list`(:class:`deltas.tokenizers.Token`)
              Changed sequence
          segmenter : :class:`deltas.Segmenter`
              A segmenter to use on the tokens.
  
      :Returns:
          An `iterable` of operations.
      """
      a, b = list(a), list(b)
      segmenter = segmenter or SEGMENTER
  
      # Cluster the input tokens
      a_segments = segmenter.segment(a)
      b_segments = segmenter.segment(b)
  
      return diff_segments(a_segments, b_segments)