Changelog

All notable changes will be documented here. The format is based on Keep a Changelog. Lilo adheres to Semantic Versioning.

Unreleased

v0.5.1 - 2025-11-05

Added

• New spec export format: RTAMT.
• New documentation site: https://docs.imiron.io/.
• You can now create animation gif animations.
• Projects are setup with a lilo.toml file, see Project Configuration.
• Registration of system falsifiers in lilo.toml.
• VSCode spec status now lists analysis.
• Spec analysis in VSCode.
• Run falsification engines from the spec analysis pane.

Changed

• Better type errors for conflicting record construction/update.
• LLM explanations are localised according to user's VSCode settings.
• Unbound variable errors now include a list of in-scope variables with similar spellings.
• System globals (signals and params) can have attributes, including docstrings.
• The command JSON format has changed significantly, as is expected to be stable (backwards compatible) going forwards. In particular this uses system names, not filenames.
• One can specify a param as null (JSON) to remove the default param values.
• LLM spec generation will fail for under-specified specifications.
• CLI interface is updated to work with modules.

v0.5.0 - 2025-10-14

Added

• Default params: param foo: Float = 42 sets 42 as the default value of parameter foo.
• Timeout attributes:

  #[timeout = 3]
  spec foo = ...
  

  will set the timeout to 3 seconds for analysis tasks on spec foo.
• Warning for mismatched server/client versions.
• Spec stubs:

  spec no_overheat
  

  creates a "spec stub" (an unimplemented spec). There is also a code action to suggest an implementation using the docstring, using AI.
• Retry analysis with longer timeout: if an analysis times out, there is a code action to retry with a longer timeout.
• Record features:
  • Record update (including deep)
  • Field punning.
  • Path construction and path update.
• Warnings for unused defs, signals and params.
• Code hierarchy in VSCode.
• Modules: User can create modules (containing only def and type declarations), and import them.

Changed

• VSCode code lenses resolve one at a time, which results in a much more responsive experience.