feat: constructor for GalileanSpatialTranslationOperator (#192)

* feat: constructor for GalileanSpatialTranslationOperator
* ci: ignore pylint arguments-differ because of plum

Signed-off-by: nstarman <nstarman@users.noreply.github.com>

pyproject.toml

@@ -208,6 +208,7 @@
   ignore-paths = [".*/_version.py"]
   messages_control.disable = [
     "abstract-method",            # pylint doesn't like ABC hierarchies
+    "arguments-differ",           # plum-dispatch
     "cyclic-import",              # broken?
     "design",
     "duplicate-code",

src/coordinax/_src/operators/galilean/translation.py

@@ -6,9 +6,11 @@
 
 from dataclasses import replace
 from typing import Any, Literal, final
+from typing_extensions import override
 
 import equinox as eqx
-from plum import convert
+from jaxtyping import ArrayLike
+from plum import convert, dispatch
 
 import quaxed.numpy as jnp
 from unxt import Quantity
@@ -176,6 +178,54 @@ class GalileanSpatialTranslationOperator(AbstractGalileanOperator):
 
     # -------------------------------------------
 
+    @override
+    @classmethod
+    @dispatch
+    def constructor(
+        cls: "type[GalileanSpatialTranslationOperator]",
+        x: ArrayLike | list[float | int],
+        unit: str,  # TODO: support unit object
+        /,
+    ) -> "GalileanSpatialTranslationOperator":
+        """Construct a spatial translation operator.
+
+        Examples
+        --------
+        >>> from unxt import Quantity
+        >>> import coordinax as cx
+
+        >>> op = cx.operators.GalileanSpatialTranslationOperator.constructor([1, 1, 1], "kpc")
+        >>> op.translation.x
+        Quantity['length'](Array(1., dtype=float32), unit='kpc')
+
+        """  # noqa: E501
+        return cls(Quantity(x, unit))
+
+    @override
+    @classmethod
+    @dispatch
+    def constructor(
+        cls: "type[GalileanSpatialTranslationOperator]",
+        x: ArrayLike | list[float | int],
+        *,
+        unit: Any,
+    ) -> "GalileanSpatialTranslationOperator":
+        """Construct a spatial translation operator.
+
+        Examples
+        --------
+        >>> from unxt import Quantity
+        >>> import coordinax as cx
+
+        >>> op = cx.operators.GalileanSpatialTranslationOperator.constructor([1, 1, 1], "kpc")
+        >>> op.translation.x
+        Quantity['length'](Array(1., dtype=float32), unit='kpc')
+
+        """  # noqa: E501
+        return cls(Quantity(x, unit))
+
+    # -------------------------------------------
+
     @property
     def is_inertial(self) -> Literal[True]:
         """Galilean translation is an inertial frame-preserving transformation.