Method pop

mathematics_dataset/util/composition.py:284–294

Returns an unused symbol (and keeps track of it being used).

(self)

    return self._child_entities[:]

  def pop(self):
    """Returns an unused symbol (and keeps track of it being used)."""
    allowed = (_ALLOWED_SYMBOLS
               .difference(self._relation_symbols)
               .difference(self._self_symbols)
               .difference(self._child_symbols))
    if not allowed:
      raise ValueError('Ran out of symbols')
    symbol = random.choice(list(allowed))
    self._self_symbols.add(symbol)
    return symbol

  def mark_used(self, symbol):
    """Marks a given symbol as used."""