textattack-nlp-transformer/textattack/attack_results/attack_result.py

from textattack.goal_function_results import GoalFunctionResult
from textattack.shared import utils


class AttackResult:
    """
    Result of an Attack run on a single (output, text_input) pair. 

    Args:
        original_result (GoalFunctionResult): Result of the goal function
            applied to the original text
        perturbed_result (GoalFunctionResult): Result of the goal function applied to the
            perturbed text. May or may not have been successful.
    """

    def __init__(self, original_result, perturbed_result):
        if original_result is None:
            raise ValueError("Attack original result cannot be None")
        elif not isinstance(original_result, GoalFunctionResult):
            raise TypeError(f"Invalid original goal function result: {original_result}")
        if perturbed_result is None:
            raise ValueError("Attack perturbed result cannot be None")
        elif not isinstance(perturbed_result, GoalFunctionResult):
            raise TypeError(
                f"Invalid perturbed goal function result: {perturbed_result}"
            )

        self.original_result = original_result
        self.perturbed_result = perturbed_result
        self.num_queries = perturbed_result.num_queries

        # We don't want the AttackedText attributes sticking around clogging up
        # space on our devices. Delete them here, if they're still present,
        # because we won't need them anymore anyway.
        self.original_result.attacked_text.free_memory()
        self.perturbed_result.attacked_text.free_memory()

    def original_text(self, color_method=None):
        """ Returns the text portion of `self.original_result`. Helper method.
        """
        return self.original_result.attacked_text.printable_text(
            key_color=("bold", "underline"), key_color_method=color_method
        )

    def perturbed_text(self, color_method=None):
        """ Returns the text portion of `self.perturbed_result`. Helper method.
        """
        return self.perturbed_result.attacked_text.printable_text(
            key_color=("bold", "underline"), key_color_method=color_method
        )

    def str_lines(self, color_method=None):
        """ A list of the lines to be printed for this result's string
            representation. 
        """
        lines = [self.goal_function_result_str(color_method=color_method)]
        lines.extend(self.diff_color(color_method))
        return lines

    def __str__(self, color_method=None):
        return "\n\n".join(self.str_lines(color_method=color_method))

    def goal_function_result_str(self, color_method=None):
        """
        Returns a string illustrating the results of the goal function.
        """
        orig_colored = self.original_result.get_colored_output(color_method)
        pert_colored = self.perturbed_result.get_colored_output(color_method)
        return orig_colored + " --> " + pert_colored

    def diff_color(self, color_method=None):
        """ Highlights the difference between two texts using color.
        """
        t1 = self.original_result.attacked_text
        t2 = self.perturbed_result.attacked_text

        if color_method is None:
            return t1.printable_text(), t2.printable_text()

        color_1 = self.original_result.get_text_color_input()
        color_2 = self.perturbed_result.get_text_color_perturbed()

        words_1 = []
        words_1_idxs = []

        words_2 = []
        words_2_idxs = []

        i1 = 0
        i2 = 0

        while i1 < t1.num_words or i2 < t2.num_words:
            # show deletions
            while (
                i1 < len(t2.attack_attrs["original_index_map"])
                and t2.attack_attrs["original_index_map"][i1] == -1
            ):
                words_1.append(utils.color_text(t1.words[i1], color_1, color_method))
                words_1_idxs.append(i1)
                i1 += 1
            # show insertions
            while (
                i1 < len(t2.attack_attrs["original_index_map"])
                and i2 < t2.attack_attrs["original_index_map"][i1]
            ):
                words_2.append(utils.color_text(t1.words[i2], color_2, color_method))
                words_2_idxs.append(i2)
                i2 += 1
            # show swaps
            if i1 < t1.num_words and i2 < t2.num_words:
                word_1 = t1.words[i1]
                word_2 = t2.words[i2]
                if word_1 != word_2:
                    words_1.append(utils.color_text(word_1, color_1, color_method))
                    words_2.append(utils.color_text(word_2, color_2, color_method))
                    words_1_idxs.append(i1)
                    words_2_idxs.append(i2)
                i1 += 1
                i2 += 1

        t1 = self.original_result.attacked_text.replace_words_at_indices(
            words_1_idxs, words_1
        )
        t2 = self.perturbed_result.attacked_text.replace_words_at_indices(
            words_2_idxs, words_2
        )

        key_color = ("bold", "underline")
        return (
            t1.printable_text(key_color=key_color, key_color_method=color_method),
            t2.printable_text(key_color=key_color, key_color_method=color_method),
        )