fix: to work with 3.12 and add examples tests

.github/workflows/test.yml

@@ -39,7 +39,7 @@ jobs:
           fetch-depth: 0
       - uses: actions/setup-python@v4
         with:
-          python-version: '3.11'
+          python-version: '3.12'
           cache: 'pip' # caching pip dependencies
       - name: Install dependencies
         run: |

codebleu/bleu.py

@@ -9,25 +9,11 @@
 
 """BLEU score implementation."""
 import math
-import sys
-import warnings
 from collections import Counter
-from fractions import Fraction as _Fraction
-from typing import Any
 
 from .utils import ngrams
 
 
-# _normalize=False was removed in 3.12, add custom class for back-compatibility
-class Fraction(_Fraction):
-    # We're immutable, so use __new__ not __init__
-    def __new__(cls, numerator: Any = 0, denominator: Any = None, *, _normalize: bool = True) -> "Fraction":
-        if sys.version_info >= (3, 12):
-            return super(Fraction, cls).__new__(cls, numerator, denominator)
-        else:
-            return super(Fraction, cls).__new__(cls, numerator, denominator, _normalize=False)
-
-
 def sentence_bleu(
     references,
     hypothesis,
@@ -163,9 +149,9 @@ def corpus_bleu(
         # For each order of ngram, calculate the numerator and
         # denominator for the corpus-level modified precision.
         for i, _ in enumerate(weights, start=1):
-            p_i = modified_precision(references, hypothesis, i)
-            p_numerators[i] += p_i.numerator
-            p_denominators[i] += p_i.denominator
+            p_i_numerator, p_i_denominator = modified_precision(references, hypothesis, i)
+            p_numerators[i] += p_i_numerator
+            p_denominators[i] += p_i_denominator
 
         # Calculate the hypothesis length and the closest reference length.
         # Adds them to the corpus-level hypothesis and reference counts.
@@ -182,8 +168,8 @@ def corpus_bleu(
         if hyp_lengths < 4 and weights == (0.25, 0.25, 0.25, 0.25):
             weights = (1 / hyp_lengths,) * hyp_lengths
 
-    # Collects the various precision values for the different ngram orders.
-    p_n = [Fraction(p_numerators[i], p_denominators[i], _normalize=False) for i, _ in enumerate(weights, start=1)]
+    # Collects the various recall values for the different ngram orders.
+    p_n = [(p_numerators[i], p_denominators[i]) for i, _ in enumerate(weights, start=1)]
 
     # Returns 0 if there's no matching n-grams
     # We only need to check for p_numerators[1] == 0, since if there's
@@ -199,7 +185,7 @@ def corpus_bleu(
     #       it tries to retain the Fraction object as much as the
     #       smoothing method allows.
     p_n = smoothing_function(p_n, references=references, hypothesis=hypothesis, hyp_len=hyp_lengths)
-    s = (w_i * math.log(p_i) for w_i, p_i in zip(weights, p_n))
+    s = (w_i * math.log(p_i[0] / p_i[1]) for w_i, p_i in zip(weights, p_n))
     s = bp * math.exp(math.fsum(s))
     return s
 
@@ -295,7 +281,8 @@ def modified_precision(references, hypothesis, n):
     # Usually this happens when the ngram order is > len(reference).
     denominator = max(1, sum(counts.values()))
 
-    return Fraction(numerator, denominator, _normalize=False)
+    # return Fraction(numerator, denominator, _normalize=False)
+    return numerator, denominator
 
 
 def closest_ref_length(references, hyp_len):
@@ -444,133 +431,8 @@ def __init__(self, epsilon=0.1, alpha=5, k=5):
         self.alpha = alpha
         self.k = k
 
-    def method0(self, p_n, *args, **kwargs):
-        """
-        No smoothing.
-        """
-        p_n_new = []
-        for i, p_i in enumerate(p_n):
-            if p_i.numerator != 0:
-                p_n_new.append(p_i)
-            else:
-                _msg = str(
-                    "\nThe hypothesis contains 0 counts of {}-gram overlaps.\n"
-                    "Therefore the BLEU score evaluates to 0, independently of\n"
-                    "how many N-gram overlaps of lower order it contains.\n"
-                    "Consider using lower n-gram order or use "
-                    "SmoothingFunction()"
-                ).format(i + 1)
-                warnings.warn(_msg)
-                # When numerator==0 where denonminator==0 or !=0, the result
-                # for the precision score should be equal to 0 or undefined.
-                # Due to BLEU geometric mean computation in logarithm space,
-                # we we need to take the return sys.float_info.min such that
-                # math.log(sys.float_info.min) returns a 0 precision score.
-                p_n_new.append(sys.float_info.min)
-        return p_n_new
-
     def method1(self, p_n, *args, **kwargs):
         """
         Smoothing method 1: Add *epsilon* counts to precision with 0 counts.
         """
-        return [(p_i.numerator + self.epsilon) / p_i.denominator if p_i.numerator == 0 else p_i for p_i in p_n]
-
-    def method2(self, p_n, *args, **kwargs):
-        """
-        Smoothing method 2: Add 1 to both numerator and denominator from
-        Chin-Yew Lin and Franz Josef Och (2004) Automatic evaluation of
-        machine translation quality using longest common subsequence and
-        skip-bigram statistics. In ACL04.
-        """
-        return [Fraction(p_i.numerator + 1, p_i.denominator + 1, _normalize=False) for p_i in p_n]
-
-    def method3(self, p_n, *args, **kwargs):
-        """
-        Smoothing method 3: NIST geometric sequence smoothing
-        The smoothing is computed by taking 1 / ( 2^k ), instead of 0, for each
-        precision score whose matching n-gram count is null.
-        k is 1 for the first 'n' value for which the n-gram match count is null/
-        For example, if the text contains:
-         - one 2-gram match
-         - and (consequently) two 1-gram matches
-        the n-gram count for each individual precision score would be:
-         - n=1  =>  prec_count = 2     (two unigrams)
-         - n=2  =>  prec_count = 1     (one bigram)
-         - n=3  =>  prec_count = 1/2   (no trigram,  taking 'smoothed' value of 1 / ( 2^k ), with k=1)
-         - n=4  =>  prec_count = 1/4   (no fourgram, taking 'smoothed' value of 1 / ( 2^k ), with k=2)
-        """
-        incvnt = 1  # From the mteval-v13a.pl, it's referred to as k.
-        for i, p_i in enumerate(p_n):
-            if p_i.numerator == 0:
-                p_n[i] = 1 / (2**incvnt * p_i.denominator)
-                incvnt += 1
-        return p_n
-
-    def method4(self, p_n, references, hypothesis, hyp_len=None, *args, **kwargs):
-        """
-        Smoothing method 4:
-        Shorter translations may have inflated precision values due to having
-        smaller denominators; therefore, we give them proportionally
-        smaller smoothed counts. Instead of scaling to 1/(2^k), Chen and Cherry
-        suggests dividing by 1/ln(len(T)), where T is the length of the translation.
-        """
-        hyp_len = hyp_len if hyp_len else len(hypothesis)
-        for i, p_i in enumerate(p_n):
-            if p_i.numerator == 0 and hyp_len != 0:
-                incvnt = i + 1 * self.k / math.log(hyp_len)  # Note that this K is different from the K from NIST.
-                p_n[i] = incvnt / p_i.denominator
-        return p_n
-
-    def method5(self, p_n, references, hypothesis, hyp_len=None, *args, **kwargs):
-        """
-        Smoothing method 5:
-        The matched counts for similar values of n should be similar. To a
-        calculate the n-gram matched count, it averages the n−1, n and n+1 gram
-        matched counts.
-        """
-        hyp_len = hyp_len if hyp_len else len(hypothesis)
-        m = {}
-        # Requires an precision value for an addition ngram order.
-        p_n_plus1 = p_n + [modified_precision(references, hypothesis, 5)]
-        m[-1] = p_n[0] + 1
-        for i, p_i in enumerate(p_n):
-            p_n[i] = (m[i - 1] + p_i + p_n_plus1[i + 1]) / 3
-            m[i] = p_n[i]
-        return p_n
-
-    def method6(self, p_n, references, hypothesis, hyp_len=None, *args, **kwargs):
-        """
-        Smoothing method 6:
-        Interpolates the maximum likelihood estimate of the precision *p_n* with
-        a prior estimate *pi0*. The prior is estimated by assuming that the ratio
-        between pn and pn−1 will be the same as that between pn−1 and pn−2; from
-        Gao and He (2013) Training MRF-Based Phrase Translation Models using
-        Gradient Ascent. In NAACL.
-        """
-        hyp_len = hyp_len if hyp_len else len(hypothesis)
-        # This smoothing only works when p_1 and p_2 is non-zero.
-        # Raise an error with an appropriate message when the input is too short
-        # to use this smoothing technique.
-        assert p_n[2], "This smoothing method requires non-zero precision for bigrams."
-        for i, p_i in enumerate(p_n):
-            if i in [0, 1]:  # Skips the first 2 orders of ngrams.
-                continue
-            else:
-                pi0 = 0 if p_n[i - 2] == 0 else p_n[i - 1] ** 2 / p_n[i - 2]
-                # No. of ngrams in translation that matches the reference.
-                m = p_i.numerator
-                # No. of ngrams in translation.
-                ngrams_count = sum(1 for _ in ngrams(hypothesis, i + 1))
-                # Calculates the interpolated precision.
-                p_n[i] = (m + self.alpha * pi0) / (ngrams_count + self.alpha)
-        return p_n
-
-    def method7(self, p_n, references, hypothesis, hyp_len=None, *args, **kwargs):
-        """
-        Smoothing method 7:
-        Interpolates methods 4 and 5.
-        """
-        hyp_len = hyp_len if hyp_len else len(hypothesis)
-        p_n = self.method4(p_n, references, hypothesis, hyp_len)
-        p_n = self.method5(p_n, references, hypothesis, hyp_len)
-        return p_n
+        return [((p_i[0] + self.epsilon), p_i[1]) if p_i[0] == 0 else p_i for p_i in p_n]

codebleu/dataflow_match.py

@@ -47,11 +47,11 @@ def corpus_dataflow_match(references, candidates, lang, langso_so_file):
         candidate = candidates[i]
         for reference in references_sample:
             try:
-                candidate = remove_comments_and_docstrings(candidate, "java")
+                candidate = remove_comments_and_docstrings(candidate, lang)
             except Exception:
                 pass
             try:
-                reference = remove_comments_and_docstrings(reference, "java")
+                reference = remove_comments_and_docstrings(reference, lang)
             except Exception:
                 pass
 

codebleu/parser/build.py

@@ -1,20 +1,20 @@
 # Copyright (c) Microsoft Corporation.
 # Copyright (c) 2023 Konstantin Chernyshev.
 # Licensed under the MIT license.
-
 from tree_sitter import Language
 
-Language.build_library(
-    "my-languages.so",
-    [
-        "tree-sitter/go",
-        "tree-sitter/javascript",
-        "tree-sitter/python",
-        "tree-sitter/php",
-        "tree-sitter/java",
-        "tree-sitter/ruby",
-        "tree-sitter/c-sharp",
-        "tree-sitter/c",
-        "tree-sitter/cpp",
-    ],
-)
+if __name__ == "__main__":
+    Language.build_library(
+        "my-languages.so",
+        [
+            "tree-sitter/go",
+            "tree-sitter/javascript",
+            "tree-sitter/python",
+            "tree-sitter/php",
+            "tree-sitter/java",
+            "tree-sitter/ruby",
+            "tree-sitter/c-sharp",
+            "tree-sitter/c",
+            "tree-sitter/cpp",
+        ],
+    )

codebleu/syntax_match.py

@@ -30,23 +30,23 @@ def calc_syntax_match(references, candidate, lang, lang_so_file):
 
 
 def corpus_syntax_match(references, candidates, lang, lang_so_file):
-    # print(os.listdir())
-    JAVA_LANGUAGE = Language(lang_so_file, lang)
+    tree_sitter_language = Language(lang_so_file, lang)
     parser = Parser()
-    parser.set_language(JAVA_LANGUAGE)
+    parser.set_language(tree_sitter_language)
     match_count = 0
+    match_count_candidate_to_reference = 0
     total_count = 0
 
     for i in range(len(candidates)):
         references_sample = references[i]
         candidate = candidates[i]
         for reference in references_sample:
             try:
-                candidate = remove_comments_and_docstrings(candidate, "java")
+                candidate = remove_comments_and_docstrings(candidate, lang)
             except Exception:
                 pass
             try:
-                reference = remove_comments_and_docstrings(reference, "java")
+                reference = remove_comments_and_docstrings(reference, lang)
             except Exception:
                 pass
 
@@ -69,15 +69,21 @@ def get_all_sub_trees(root_node):
                 return sub_tree_sexp_list
 
             cand_sexps = [x[0] for x in get_all_sub_trees(candidate_tree)]
-            ref_sexps = get_all_sub_trees(reference_tree)
+            ref_sexps = [x[0] for x in get_all_sub_trees(reference_tree)]
 
-            # print(cand_sexps)
-            # print(ref_sexps)
-
-            for sub_tree, depth in ref_sexps:
+            # TODO: fix, now we count number of reference subtrees matching candidate,
+            #       but we should count number of candidate subtrees matching reference
+            #       See (4) in "3.2 Syntactic AST Match" of https://arxiv.org/pdf/2009.10297.pdf
+            for sub_tree in ref_sexps:
                 if sub_tree in cand_sexps:
                     match_count += 1
-            total_count += len(ref_sexps)
 
+            for sub_tree in cand_sexps:
+                if sub_tree in ref_sexps:
+                    match_count_candidate_to_reference += 1
+
+            total_count += len(ref_sexps)
+    # print(f'match_count       {match_count} / {total_count}')
+    # print(f'match_count_fixed {match_count_candidate_to_reference} / {total_count}')
     score = match_count / total_count
     return score