Restore 0.1.5 version from stash

wolai-backend/.venv312/Lib/site-packages/pgvector/django/functions.py

@@ -0,0 +1,55 @@
+from django.db.models import FloatField, Func, Value
+from ..utils import Vector, HalfVector, SparseVector
+
+
+class DistanceBase(Func):
+    output_field = FloatField()
+
+    def __init__(self, expression, vector, **extra):
+        if not hasattr(vector, 'resolve_expression'):
+            if isinstance(vector, HalfVector):
+                vector = Value(HalfVector._to_db(vector))
+            elif isinstance(vector, SparseVector):
+                vector = Value(SparseVector._to_db(vector))
+            else:
+                vector = Value(Vector._to_db(vector))
+        super().__init__(expression, vector, **extra)
+
+
+class BitDistanceBase(Func):
+    output_field = FloatField()
+
+    def __init__(self, expression, vector, **extra):
+        if not hasattr(vector, 'resolve_expression'):
+            vector = Value(vector)
+        super().__init__(expression, vector, **extra)
+
+
+class L2Distance(DistanceBase):
+    function = ''
+    arg_joiner = ' <-> '
+
+
+class MaxInnerProduct(DistanceBase):
+    function = ''
+    arg_joiner = ' <#> '
+
+
+class CosineDistance(DistanceBase):
+    function = ''
+    arg_joiner = ' <=> '
+
+
+class L1Distance(DistanceBase):
+    function = ''
+    arg_joiner = ' <+> '
+
+
+class HammingDistance(BitDistanceBase):
+    function = ''
+    arg_joiner = ' <~> '
+
+
+class JaccardDistance(BitDistanceBase):
+    function = ''
+    arg_joiner = ' <%%> '