Implement @ethdebug/pointers TypeScript package to serve as debugger-side reference implementation of ethdebug/format pointers

[gnidan]

This reference implementation provides a dereference(pointer) function, along with associated types.

Details

• Define new package @ethdebug/pointers

  • Setup TS build system and Jest test suite
  • Ensure yarn start includes those

• Define Pointer family of TypeScript types

  • Use namespaces to reflect schema hierarchy (Pointer.Region, etc.)
  • Provide type guards for detecting conformance to these types

• Define Machine and Machine.State interfaces to adapt external EVMs

• Define Cursor interface for inspecting machine state for a pointer

  • Include view(state: Machine.State): Promise<Cursor.Regions>
  • Define Cursor.Region as a region with all expressions evaluated
  • Define Cursor.Regions as an array-like collection of regions

• Implement read functionality for a Cursor.Region

• Implement evaluate functionality for a Pointer.Expression

• Implement dereference functionality to get a Cursor from a Pointer

• Include integration tests that use solc and Ganache to ensure expected pointer changes occur over the lifetime of an actual transaction