Fst Writer#671
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Clarify comment Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>
Adds FST format support as an alternative output format for WaveDumper: - lib/src/fst/fst_types.dart: FST type definitions (FstVarType, FstVarDirection, FstScopeType, FstFileType, FstSignalHandle, FstWriterConfig) - lib/src/fst/fst_writer.dart: GTKWave-compatible binary FST writer - lib/src/wave_dumper.dart: adds WaveFormat enum (vcd/fst) and FST format support - lib/rohd.dart: exports fst_types.dart and fst_writer.dart - test/fst_writer_test.dart: FST writer tests No DevTools integration on this branch; that is added later.
Uses Directory.createSync / dart:io — fails on JS with _Namespace error.
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| // Copyright (C) 2021-2026 Intel Corporation | |||
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nit: new file not copyrighted since 2021?
| final FstWriterConfig? fstConfig; | ||
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| /// The file to write dumped output waveform to (VCD only). | ||
| File? _outputFile; |
| // ─────────────── VCD initialization ─────────────── | ||
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| /// Initializes VCD output. | ||
| void _initVcd() { |
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it feels a little odd that all the VCD-specific stuff lives in wave_dumper, but all the FST-specific stuff is in a separate FSTWriter. Should we extract a common API of some sort for "writers" rather than have such a difference in implementation?
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I am applying this comment to fst-writer which will have the WaveformService form of API. This branch was designed to be mergeable independent of module_services_api as I wasn't sure when we would merge. FST is interesting for exploring waveforms with structure (array/struct).
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Actually it just seems easier to merge this after module_services_api. So I will presume this from now on to make it easier to review.
| export 'src/exceptions/exceptions.dart'; | ||
| export 'src/external.dart'; | ||
| export 'src/finite_state_machine.dart'; | ||
| export 'src/fst/fst_types.dart'; |
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it might be nice to have our vcd tests and fst tests somehow both parse the same simulation and confirm that both saw certain events at the same times
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Description & Motivation
It would be nice to have a
WaveDumperthat can output the FST format because it is much more dense and can be incrementally accessed.Related Issue(s)
None
Testing
We ran the output through a few tools, notably Wellen and GTKwave.
Backwards-compatibility
No.
Documentation
No. We will need to add. But at the user level, it becomes a choice between VCD and FST>