Vector types: optimize error path (#1226)

The pure-python implementations of `Vector.from_native` perform type checks.
This patch makes the driver fail fast when passing incompatible types instead
of scanning the whole Iterable parameter.

Author: robsdedude

src/neo4j/vector.py

@@ -53,6 +53,9 @@
 ]
 
 
+_DEFAULT = object()
+
+
 class Vector:
     r"""
     A class representing a Neo4j vector.
@@ -753,10 +756,11 @@ def _from_native_rust(cls, data: _t.Iterable[object], /) -> _t.Self:
     @classmethod
     def _from_native_np(cls, data: _t.Iterable[object], /) -> _t.Self:
         data = tuple(data)
-        non_float = tuple(item for item in data if not isinstance(item, float))
-        if non_float:
+        non_float_gen = (item for item in data if not isinstance(item, float))
+        non_float = next(non_float_gen, _DEFAULT)
+        if non_float is not _DEFAULT:
             raise TypeError(
-                f"Cannot build f64 vector from {type(non_float[0]).__name__}, "
+                f"Cannot build f64 vector from {type(non_float).__name__}, "
                 "expected float."
             )
         return cls(_np.fromiter(data, dtype=_np.dtype(">f8")).tobytes())
@@ -826,10 +830,11 @@ def _from_native_rust(cls, data: _t.Iterable[object], /) -> _t.Self:
     @classmethod
     def _from_native_np(cls, data: _t.Iterable[object], /) -> _t.Self:
         data = tuple(data)
-        non_float = tuple(item for item in data if not isinstance(item, float))
-        if non_float:
+        non_float_gen = (item for item in data if not isinstance(item, float))
+        non_float = next(non_float_gen, _DEFAULT)
+        if non_float is not _DEFAULT:
             raise TypeError(
-                f"Cannot build f32 vector from {type(non_float[0]).__name__}, "
+                f"Cannot build f32 vector from {type(non_float).__name__}, "
                 "expected float."
             )
         return cls(_np.fromiter(data, dtype=_np.dtype(">f4")).tobytes())
@@ -903,10 +908,11 @@ def _from_native_rust(cls, data: _t.Iterable[object], /) -> _t.Self:
     @classmethod
     def _from_native_np(cls, data: _t.Iterable[object], /) -> _t.Self:
         data = tuple(data)
-        non_int = tuple(item for item in data if not isinstance(item, int))
-        if non_int:
+        non_int_gen = (item for item in data if not isinstance(item, int))
+        non_int = next(non_int_gen, _DEFAULT)
+        if non_int is not _DEFAULT:
             raise TypeError(
-                f"Cannot build i64 vector from {type(non_int[0]).__name__}, "
+                f"Cannot build i64 vector from {type(non_int).__name__}, "
                 "expected int."
             )
         data = _t.cast(tuple[int, ...], data)
@@ -994,10 +1000,11 @@ def _from_native_rust(cls, data: _t.Iterable[object], /) -> _t.Self:
     @classmethod
     def _from_native_np(cls, data: _t.Iterable[object], /) -> _t.Self:
         data = tuple(data)
-        non_int = tuple(item for item in data if not isinstance(item, int))
-        if non_int:
+        non_int_gen = (item for item in data if not isinstance(item, int))
+        non_int = next(non_int_gen, _DEFAULT)
+        if non_int is not _DEFAULT:
             raise TypeError(
-                f"Cannot build i32 vector from {type(non_int[0]).__name__}, "
+                f"Cannot build i32 vector from {type(non_int).__name__}, "
                 "expected int."
             )
         data = _t.cast(tuple[int, ...], data)
@@ -1085,10 +1092,11 @@ def _from_native_rust(cls, data: _t.Iterable[object], /) -> _t.Self:
     @classmethod
     def _from_native_np(cls, data: _t.Iterable[object], /) -> _t.Self:
         data = tuple(data)
-        non_int = tuple(item for item in data if not isinstance(item, int))
-        if non_int:
+        non_int_gen = (item for item in data if not isinstance(item, int))
+        non_int = next(non_int_gen, _DEFAULT)
+        if non_int is not _DEFAULT:
             raise TypeError(
-                f"Cannot build i16 vector from {type(non_int[0]).__name__}, "
+                f"Cannot build i16 vector from {type(non_int).__name__}, "
                 "expected int."
             )
         data = _t.cast(tuple[int, ...], data)
@@ -1176,10 +1184,11 @@ def _from_native_rust(cls, data: _t.Iterable[object], /) -> _t.Self:
     @classmethod
     def _from_native_np(cls, data: _t.Iterable[object], /) -> _t.Self:
         data = tuple(data)
-        non_int = tuple(item for item in data if not isinstance(item, int))
-        if non_int:
+        non_int_gen = (item for item in data if not isinstance(item, int))
+        non_int = next(non_int_gen, _DEFAULT)
+        if non_int is not _DEFAULT:
             raise TypeError(
-                f"Cannot build i8 vector from {type(non_int[0]).__name__}, "
+                f"Cannot build i8 vector from {type(non_int).__name__}, "
                 "expected int."
             )
         data = _t.cast(tuple[int, ...], data)