Switch from intelligent save to intelligent load

Use the concept of Settings that can be:
- Created from a Device
- Stored to YAML
- Retrieved from YAML
- Added to other Settings
- Applied to a Device

.gitignore

@@ -87,6 +87,8 @@ docs/savefig
 # generated version number
 ophyd_async/_version.py
 
-
 # ruff cache
 .ruff_cache/
+
+# import linter cache
+.import_linter_cache/

pyproject.toml

@@ -159,6 +159,9 @@ lint.select = [
     "SLF",     # self - https://docs.astral.sh/ruff/settings/#lintflake8-self
     "PLC2701", # private import - https://docs.astral.sh/ruff/rules/import-private-name/
 ]
+lint.ignore = [
+    "B901", # Return in a generator is needed for plans
+]
 lint.preview = true # so that preview mode PLC2701 is enabled
 
 [tool.ruff.lint.per-file-ignores]
@@ -172,47 +175,26 @@ lint.preview = true # so that preview mode PLC2701 is enabled
 root_package = "ophyd_async"
 
 [[tool.importlinter.contracts]]
-name = "Core is independent"
-type = "independence"
-modules = "ophyd_async.core"
+name = "All runtime modules are in layers"
+type = "layers"
+containers = ["ophyd_async"]
+layers = ["plan_stubs", "fastcs", "epics | tango | sim", "core"]
+exhaustive = true
+exhaustive_ignores = ["testing", "_version", "__main__"]
 
 [[tool.importlinter.contracts]]
-name = "Epics depends only on core"
-type = "forbidden"
-source_modules = "ophyd_async.epics"
-forbidden_modules = [
-    "ophyd_async.fastcs",
-    "ophyd_async.plan_stubs",
-    "ophyd_async.sim",
-    "ophyd_async.tango",
-]
+name = "Testing modules"
+type = "layers"
+containers = ["ophyd_async"]
+layers = ["testing", "core"]
 
 [[tool.importlinter.contracts]]
-name = "tango depends only on core"
+name = "Testing modules are not used at runtime"
 type = "forbidden"
-source_modules = "ophyd_async.tango"
+source_modules = "ophyd_async.testing"
 forbidden_modules = [
-    "ophyd_async.epics",
-    "ophyd_async.fastcs",
     "ophyd_async.plan_stubs",
-    "ophyd_async.sim",
-]
-
-
-[[tool.importlinter.contracts]]
-name = "sim depends only on core"
-type = "forbidden"
-source_modules = "ophyd_async.sim"
-forbidden_modules = [
-    "ophyd_async.epics",
     "ophyd_async.fastcs",
-    "ophyd_async.plan_stubs",
+    "ophyd_async.epics",
     "ophyd_async.tango",
 ]
-
-
-[[tool.importlinter.contracts]]
-name = "Fastcs depends only on core, epics, tango"
-type = "forbidden"
-source_modules = "ophyd_async.fastcs"
-forbidden_modules = ["ophyd_async.plan_stubs", "ophyd_async.sim"]

src/ophyd_async/core/__init__.py

@@ -7,16 +7,6 @@
 )
 from ._device import Device, DeviceCollector, DeviceConnector, DeviceVector
 from ._device_filler import DeviceFiller
-from ._device_save_loader import (
-    all_at_once,
-    get_signal_values,
-    load_device,
-    load_from_yaml,
-    save_device,
-    save_to_yaml,
-    set_signal_values,
-    walk_rw_signals,
-)
 from ._flyer import FlyerController, StandardFlyer
 from ._hdf_dataset import HDFDataset, HDFFile
 from ._log import config_ophyd_async_logging
@@ -41,6 +31,7 @@
     StandardReadable,
     StandardReadableFormat,
 )
+from ._settings import Settings, SettingsProvider
 from ._signal import (
     Signal,
     SignalConnector,
@@ -55,9 +46,11 @@
     soft_signal_r_and_setter,
     soft_signal_rw,
     wait_for_value,
+    walk_rw_signals,
 )
 from ._signal_backend import (
     Array1D,
+    DTypeScalar_co,
     SignalBackend,
     SignalDatatype,
     SignalDatatypeT,
@@ -84,6 +77,7 @@
     in_micros,
     wait_for_connection,
 )
+from ._yaml_settings import YamlSettingsProvider
 
 __all__ = [
     "DetectorController",
@@ -96,14 +90,6 @@
     "DeviceCollector",
     "DeviceVector",
     "DeviceFiller",
-    "all_at_once",
-    "get_signal_values",
-    "load_device",
-    "load_from_yaml",
-    "save_device",
-    "save_to_yaml",
-    "set_signal_values",
-    "walk_rw_signals",
     "StandardFlyer",
     "FlyerController",
     "HDFDataset",
@@ -128,6 +114,8 @@
     "HintedSignal",
     "StandardReadable",
     "StandardReadableFormat",
+    "Settings",
+    "SettingsProvider",
     "Signal",
     "SignalConnector",
     "SignalR",
@@ -141,7 +129,9 @@
     "soft_signal_r_and_setter",
     "soft_signal_rw",
     "wait_for_value",
+    "walk_rw_signals",
     "Array1D",
+    "DTypeScalar_co",
     "SignalBackend",
     "make_datakey",
     "StrictEnum",
@@ -168,4 +158,5 @@
     "in_micros",
     "wait_for_connection",
     "completed_status",
+    "YamlSettingsProvider",
 ]