utils.py

# Answer parsing and normalization code, from
# https://github.com/ruixiangcui/AGIEval/blob/main/src/
# math_equivalence.py and post_process.py
import re
from typing import Dict, List

import numpy as np


def parse_math_answer(raw_string):
    def remove_boxed(s):
        left = "\\boxed{"
        try:
            assert s[: len(left)] == left
            assert s[-1] == "}"
            answer = s[len(left) : -1]
            if "=" in answer:
                answer = answer.split("=")[-1].lstrip(" ")
            return answer
        except Exception:
            return None

    def last_boxed_only_string(string):
        idx = string.rfind("\\boxed")
        if idx < 0:
            idx = string.rfind("\\fbox")
            if idx < 0:
                return None
        i = idx
        right_brace_idx = None
        num_left_braces_open = 0
        while i < len(string):
            if string[i] == "{":
                num_left_braces_open += 1
            if string[i] == "}":
                num_left_braces_open -= 1
                if num_left_braces_open == 0:
                    right_brace_idx = i
                    break
            i += 1

        if right_brace_idx is None:
            retval = None
        else:
            retval = string[idx : right_brace_idx + 1]

        return retval

    def get_answer_with_dollar_sign(s):
        first_pattern = "\$(.*)\$"
        last_match = None
        matches = re.findall(first_pattern, s)
        if matches:
            last_match = matches[-1]
            if "=" in last_match:
                last_match = last_match.split("=")[-1].lstrip(" ")
        return last_match

    def get_answer_without_dollar_sign(s):
        last_match = None
        if "=" in s:
            last_match = s.split("=")[-1].lstrip(" ").rstrip(".")
            if "\\n" in last_match:
                last_match = last_match.split("\\n")[0]
        else:
            pattern = "(?:\\$)?\d+(?:\.\d+)?(?![\w\d])"
            matches = re.findall(pattern, s)
            if matches:
                last_match = matches[-1]
        return last_match

    if "\\boxed" in raw_string:
        answer = remove_boxed(last_boxed_only_string(raw_string))
    else:
        answer = get_answer_with_dollar_sign(raw_string)
        if not answer:
            answer = get_answer_without_dollar_sign(raw_string)
    return answer


# code from https://github.com/hendrycks/math/blob/main/modeling/math_equivalence.py
def _fix_fracs(string):
    substrs = string.split("\\frac")
    new_str = substrs[0]
    if len(substrs) > 1:
        substrs = substrs[1:]
        for substr in substrs:
            new_str += "\\frac"
            if substr[0] == "{":
                new_str += substr
            else:
                try:
                    assert len(substr) >= 2
                except Exception:
                    return string
                a = substr[0]
                b = substr[1]
                if b != "{":
                    if len(substr) > 2:
                        post_substr = substr[2:]
                        new_str += "{" + a + "}{" + b + "}" + post_substr
                    else:
                        new_str += "{" + a + "}{" + b + "}"
                else:
                    if len(substr) > 2:
                        post_substr = substr[2:]
                        new_str += "{" + a + "}" + b + post_substr
                    else:
                        new_str += "{" + a + "}" + b
    string = new_str
    return string


def _fix_a_slash_b(string):
    if len(string.split("/")) != 2:
        return string
    a = string.split("/")[0]
    b = string.split("/")[1]
    try:
        a = int(a)
        b = int(b)
        assert string == "{}/{}".format(a, b)
        new_string = "\\frac{" + str(a) + "}{" + str(b) + "}"
        return new_string
    except Exception:
        return string


def _remove_right_units(string):
    # "\\text{ " only ever occurs (at least in the val set) when describing units
    if "\\text{ " in string:
        splits = string.split("\\text{ ")
        assert len(splits) == 2
        return splits[0]
    else:
        return string


def _fix_sqrt(string):
    if "\\sqrt" not in string:
        return string
    splits = string.split("\\sqrt")
    new_string = splits[0]
    for split in splits[1:]:
        if split[0] != "{":
            a = split[0]
            new_substr = "\\sqrt{" + a + "}" + split[1:]
        else:
            new_substr = "\\sqrt" + split
        new_string += new_substr
    return new_string


def _strip_string(string):
    # linebreaks
    string = string.replace("\n", "")
    # print(string)

    # remove inverse spaces
    string = string.replace("\\!", "")
    # print(string)

    # replace \\ with \
    string = string.replace("\\\\", "\\")
    # print(string)

    # replace tfrac and dfrac with frac
    string = string.replace("tfrac", "frac")
    string = string.replace("dfrac", "frac")
    # print(string)

    # remove \left and \right
    string = string.replace("\\left", "")
    string = string.replace("\\right", "")
    # print(string)

    # Remove circ (degrees)
    string = string.replace("^{\\circ}", "")
    string = string.replace("^\\circ", "")

    # remove dollar signs
    string = string.replace("\\$", "")

    # remove units (on the right)
    string = _remove_right_units(string)

    # remove percentage
    string = string.replace("\\%", "")
    string = string.replace("\%", "")

    # " 0." equivalent to " ." and "{0." equivalent to "{." Alternatively, add "0" if "." is the start of the string
    string = string.replace(" .", " 0.")
    string = string.replace("{.", "{0.")
    # if empty, return empty string
    if len(string) == 0:
        return string
    if string[0] == ".":
        string = "0" + string

    # to consider: get rid of e.g. "k = " or "q = " at beginning
    if len(string.split("=")) == 2:
        if len(string.split("=")[0]) <= 2:
            string = string.split("=")[1]

    # fix sqrt3 --> sqrt{3}
    string = _fix_sqrt(string)

    # remove spaces
    string = string.replace(" ", "")

    # \frac1b or \frac12 --> \frac{1}{b} and \frac{1}{2}, etc. Even works with \frac1{72} (but not \frac{72}1). Also does a/b --> \\frac{a}{b}
    string = _fix_fracs(string)

    # manually change 0.5 --> \frac{1}{2}
    if string == "0.5":
        string = "\\frac{1}{2}"

    # NOTE: X/Y changed to \frac{X}{Y} in dataset, but in simple cases fix in case the model output is X/Y
    string = _fix_a_slash_b(string)

    return string


def is_equiv(str1, str2, verbose=False):
    if str1 is None and str2 is None:
        print("WARNING: Both None")
        return True
    if str1 is None or str2 is None:
        return False

    str1, str2 = parse_math_answer(str1), parse_math_answer(str2)

    try:
        ss1 = _strip_string(str1)
        ss2 = _strip_string(str2)
        if verbose:
            print(ss1, ss2)
        return ss1 == ss2
    except Exception:
        return str1 == str2


def process_results(doc: dict, results: List[str]) -> Dict[str, int]:
    candidate = results[0]

    gold = doc["answer"]

    if not gold:
        print(doc, candidate, gold)
    if is_equiv(candidate, gold):
        retval = 1
    else:
        retval = 0

    results = {
        "acc": retval,
    }
    return results


# use a custom process_results() function, because AGIEval can have multiple valid answers
def process_results_mcqa(doc, results):
    results = [result[0] for result in results]

    gold = doc["gold"]

    acc = 1.0 if int(np.argmax(results)) in gold else 0.0
    completion_len = np.array([float(len(i)) for i in doc["choices"]])
    acc_norm = 1.0 if int(np.argmax(results / completion_len)) in gold else 0.0

    return {
        "acc": acc,
        "acc_norm": acc_norm,
    }