2026-1-6

venv/Lib/site-packages/whoosh/lang/snowball/swedish.py

@@ -0,0 +1,80 @@
+from .bases import _ScandinavianStemmer
+
+from whoosh.compat import u
+
+
+class SwedishStemmer(_ScandinavianStemmer):
+
+    """
+    The Swedish Snowball stemmer.
+
+    :cvar __vowels: The Swedish vowels.
+    :type __vowels: unicode
+    :cvar __s_ending: Letters that may directly appear before a word final 's'.
+    :type __s_ending: unicode
+    :cvar __step1_suffixes: Suffixes to be deleted in step 1 of the algorithm.
+    :type __step1_suffixes: tuple
+    :cvar __step2_suffixes: Suffixes to be deleted in step 2 of the algorithm.
+    :type __step2_suffixes: tuple
+    :cvar __step3_suffixes: Suffixes to be deleted in step 3 of the algorithm.
+    :type __step3_suffixes: tuple
+    :note: A detailed description of the Swedish
+           stemming algorithm can be found under
+           http://snowball.tartarus.org/algorithms/swedish/stemmer.html
+    """
+
+    __vowels = u("aeiouy\xE4\xE5\xF6")
+    __s_ending = "bcdfghjklmnoprtvy"
+    __step1_suffixes = ("heterna", "hetens", "heter", "heten",
+                        "anden", "arnas", "ernas", "ornas", "andes",
+                        "andet", "arens", "arna", "erna", "orna",
+                        "ande", "arne", "aste", "aren", "ades",
+                        "erns", "ade", "are", "ern", "ens", "het",
+                        "ast", "ad", "en", "ar", "er", "or", "as",
+                        "es", "at", "a", "e", "s")
+    __step2_suffixes = ("dd", "gd", "nn", "dt", "gt", "kt", "tt")
+    __step3_suffixes = ("fullt", u("l\xF6st"), "els", "lig", "ig")
+
+    def stem(self, word):
+        """
+        Stem a Swedish word and return the stemmed form.
+
+        :param word: The word that is stemmed.
+        :type word: str or unicode
+        :return: The stemmed form.
+        :rtype: unicode
+
+        """
+        word = word.lower()
+
+        r1 = self._r1_scandinavian(word, self.__vowels)
+
+        # STEP 1
+        for suffix in self.__step1_suffixes:
+            if r1.endswith(suffix):
+                if suffix == "s":
+                    if word[-2] in self.__s_ending:
+                        word = word[:-1]
+                        r1 = r1[:-1]
+                else:
+                    word = word[:-len(suffix)]
+                    r1 = r1[:-len(suffix)]
+                break
+
+        # STEP 2
+        for suffix in self.__step2_suffixes:
+            if r1.endswith(suffix):
+                word = word[:-1]
+                r1 = r1[:-1]
+                break
+
+        # STEP 3
+        for suffix in self.__step3_suffixes:
+            if r1.endswith(suffix):
+                if suffix in ("els", "lig", "ig"):
+                    word = word[:-len(suffix)]
+                elif suffix in ("fullt", u("l\xF6st")):
+                    word = word[:-1]
+                break
+
+        return word