Refactor into an internal _samplers sub-package.

Author: lohedges

src/somd2/runner/_base.py

@@ -680,7 +680,7 @@ def __init__(self, system, config):
                 raise ValueError(msg)
 
             # Auto-detect terminal ring groups using Sire connectivity.
-            from ._terminal_flip import detect_terminal_groups
+            from ._samplers import detect_terminal_groups
 
             if isinstance(self._system, list):
                 mols = self._system[0]

src/somd2/runner/_repex.py

@@ -856,7 +856,7 @@ def __init__(self, system, config):
 
         # Create the terminal flip sampler (if terminal groups were detected).
         if self._terminal_groups:
-            from ._terminal_flip import TerminalFlipSampler
+            from ._samplers import TerminalFlipSampler
 
             self._terminal_flip_sampler = TerminalFlipSampler(
                 self._terminal_groups,

src/somd2/runner/_runner.py

@@ -467,7 +467,7 @@ def generate_lam_vals(lambda_base, increment=0.001):
 
         # Create the terminal flip sampler (if terminal groups were detected).
         if self._terminal_groups:
-            from ._terminal_flip import TerminalFlipSampler
+            from ._samplers import TerminalFlipSampler
 
             terminal_flip_sampler = TerminalFlipSampler(
                 self._terminal_groups,

src/somd2/runner/_samplers/__init__.py

@@ -0,0 +1,23 @@
+######################################################################
+# SOMD2: GPU accelerated alchemical free-energy engine.
+#
+# Copyright: 2023-2026
+#
+# Authors: The OpenBioSim Team <team@openbiosim.org>
+#
+# SOMD2 is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# SOMD2 is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with SOMD2. If not, see <http://www.gnu.org/licenses/>.
+#####################################################################
+
+from ._terminal_flip import TerminalFlipSampler as TerminalFlipSampler
+from ._terminal_flip import detect_terminal_groups as detect_terminal_groups

src/somd2/runner/_terminal_flip.py …somd2/runner/_samplers/_terminal_flip.pysrc/somd2/runner/_terminal_flip.py renamed to src/somd2/runner/_samplers/_terminal_flip.py src/somd2/runner/_terminal_flip.py renamed to src/somd2/runner/_samplers/_terminal_flip.py

@@ -22,7 +22,7 @@
 
 from somd2.config import Config
 from somd2.runner import Runner
-from somd2.runner._terminal_flip import TerminalFlipSampler, detect_terminal_groups
+from somd2.runner._samplers import TerminalFlipSampler, detect_terminal_groups
 
 # ---------------------------------------------------------------------------
 # detect_terminal_groups