Upload New File

stbi/Lib/site-packages/Sastrawi/Stemmer/Context/Context.py

+from Sastrawi.Stemmer.ConfixStripping.PrecedenceAdjustmentSpecification \
+   import PrecedenceAdjustmentSpecification
+
+class Context(object):
+    """Stemming Context using Nazief and Adriani, CS, ECS, Improved ECS"""
+
+    def __init__(self, original_word, dictionary, visitor_provider):
+        self.original_word = original_word
+        self.current_word = original_word
+        self.dictionary = dictionary
+        self.visitor_provider = visitor_provider
+
+        self.process_is_stopped = False
+        self.removals = []
+        self.visitors = []
+        self.suffix_visitors = []
+        self.prefix_pisitors = []
+        self.result = ''
+
+        self.init_visitors()
+
+    def init_visitors(self):
+        self.visitors = self.visitor_provider.get_visitors()
+        self.suffix_visitors = self.visitor_provider.get_suffix_visitors()
+        self.prefix_pisitors = self.visitor_provider.get_prefix_visitors()
+
+    def stopProcess(self):
+        self.process_is_stopped = True
+
+    def add_removal(self, removal):
+        self.removals.append(removal)
+
+    def execute(self):
+        """Execute stemming process; the result can be retrieved with result"""
+
+        #step 1 - 5
+        self.start_stemming_process()
+
+        #step 6
+        if self.dictionary.contains(self.current_word):
+            self.result = self.current_word
+        else:
+            self.result = self.original_word
+
+    def start_stemming_process(self):
+
+        #step 1
+        if self.dictionary.contains(self.current_word):
+            return
+        self.accept_visitors(self.visitors)
+        if self.dictionary.contains(self.current_word):
+            return
+
+        csPrecedenceAdjustmentSpecification = PrecedenceAdjustmentSpecification()
+
+        #Confix Stripping
+        #Try to remove prefix before suffix if the specification is met
+        if csPrecedenceAdjustmentSpecification.is_satisfied_by(self.original_word):
+            #step 4, 5
+            self.remove_prefixes()
+            if self.dictionary.contains(self.current_word):
+                return
+
+            #step 2, 3
+            self.remove_suffixes()
+            if self.dictionary.contains(self.current_word):
+                return
+            else:
+                #if the trial is failed, restore the original word
+                #and continue to normal rule precedence (suffix first, prefix afterwards)
+                self.current_word = self.original_word
+                self.removals = []
+
+        #step 2, 3
+        self.remove_suffixes()
+        if self.dictionary.contains(self.current_word):
+            return
+
+        #step 4, 5
+        self.remove_prefixes()
+        if self.dictionary.contains(self.current_word):
+            return
+
+        #ECS loop pengembalian akhiran
+        self.loop_pengembalian_akhiran()
+
+    def remove_prefixes(self):
+        for i in range(3):
+            self.accept_prefix_visitors(self.prefix_pisitors)
+            if self.dictionary.contains(self.current_word):
+                return
+
+    def remove_suffixes(self):
+        self.accept_visitors(self.suffix_visitors)
+
+    def accept(self, visitor):
+        visitor.visit(self)
+
+    def accept_visitors(self, visitors):
+        for visitor in visitors:
+            self.accept(visitor)
+            if self.dictionary.contains(self.current_word):
+                return self.current_word
+            if self.process_is_stopped:
+                return self.current_word
+
+    def accept_prefix_visitors(self, visitors):
+        removalCount = len(self.removals)
+        for visitor in visitors:
+            self.accept(visitor)
+            if self.dictionary.contains(self.current_word):
+                return self.current_word
+            if self.process_is_stopped:
+                return self.current_word
+            if len(self.removals) > removalCount:
+                return
+
+    def loop_pengembalian_akhiran(self):
+        """ECS Loop Pengembalian Akhiran"""
+        self.restore_prefix()
+
+        removals = self.removals
+        reversed_removals = reversed(removals)
+        current_word = self.current_word
+
+        for removal in reversed_removals:
+            if not self.is_suffix_removal(removal):
+                continue
+            if removal.get_removed_part() == 'kan':
+                self.current_word = removal.result + 'k'
+
+                #step 4,5
+                self.remove_prefixes()
+                if self.dictionary.contains(self.current_word):
+                    return
+                self.current_word = removal.result + 'kan'
+            else:
+                self.current_word = removal.get_subject()
+
+            #step 4,5
+            self.remove_prefixes()
+            if self.dictionary.contains(self.current_word):
+                return
+
+            self.removals = removals
+            self.current_word = current_word
+
+    def is_suffix_removal(self, removal):
+        """Check wether the removed part is a suffix"""
+        return removal.get_affix_type() == 'DS' \
+               or removal.get_affix_type() == 'PP' \
+               or removal.get_affix_type() == 'P'
+
+    def restore_prefix(self):
+        """Restore prefix to proceed with ECS loop pengembalian akhiran"""
+        for removal in self.removals:
+            #return the word before precoding (the subject of first prefix removal)
+            self.current_word = removal.get_subject()
+            break
+
+        for removal in self.removals:
+            if removal.get_affix_type() == 'DP':
+                self.removals.remove(removal)
+