Modular linking between PyAT and PyAML elements

[gupichon]

Summary

The current link between PyAT lattice elements and PyAML elements relies on the FamName field.
This mechanism is limited and often leads to awkward workarounds — for example, in RWHardwareScalar and RWStrengthScalar, which retrieve a list of elements by FamName but end up using only the first one.

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Proposal

Introduce a modular linking system to define how PyAT elements are matched with PyAML elements.

• The linking logic would be handled by dedicated modules.

• A default module would keep the current FamName behavior for backward compatibility.

• Other strategies could include:

  • Linking by PyAT element index,
  • Linking by a user-defined attribute (e.g., a custom property in the lattice).

The chosen linking module (including possible custom implementations defined outside pyaml) would be declared in the simulator section of the YAML configuration.

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Benefits

• Improved flexibility for different naming conventions and lattice structures
• Cleaner and more consistent code in element access classes
• Easier integration with custom or external mapping logic

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Tasks

• Define a base interface for linking modules
• Implement a default FamNameLinker (current behavior)
• Implement alternative linkers (IndexLinker, AttributeLinker, …)
• Add configuration entry under simulator.linker
• Update existing components (RWHardwareScalar, RWStrengthScalar, etc.)
• Write documentation and examples

Originally posted by @gupichon in python-accelerator-middle-layer/governance#10 (comment)