Changelog for haal

All notable changes to this project will be documented in this file.

The format is based on Keep a Changelog, and this project adheres to the Haskell Package Versioning Policy.

Unreleased

0.5.0.0 - 2026-04-22

Fixed

• Haal.Learning.LMstar.equivalenceClasses now iterates over Sm only, matching Definition 2 of Shahbaz & Groz, "Inferring Mealy Machines". Previously it iterated over Sm ∪ Sm·I, which could pick a representative from Sm·I whose rep++[i] was not in the observation table, causing makeHypothesis to fail on many real protocol models (DTLS, medium MQTT) with "invariant violation — makeHypothesis failed on closed consistent table".

Changed (breaking)

• Haal.Learning.LMstar.otIsConsistent tightens its output constraint from Eq o to Ord o to support Map-based row grouping.

Changed

• Haal.Learning.LMstar.otIsConsistent groups prefixes by row signature before pairwise comparison, reducing the worst-case pair enumeration.
• Haal.Dot.parseDot uses Set.fromList instead of nub for deduplication (O(n²) → O(n log n)).

Added

• tasty-bench-based benchmark suite in bench/ covering BlackBox operations, W-method / Wp-method test-suite generation, DOT serialize/parse/roundtrip, and end-to-end learning experiments. Run with stack bench haal.

0.4.1.0 - 2026-03-21

Added

• Serializer from Mealy Automaton to Dot format.
• haal-gen executable that accepts a .dot file and produces a haskell module that exports a function for the specified Mealy Automaton, with specific input and output types, rather than just using String for both.
• haal-models subpackage that exports learned models of tls, mqtt, tcp and dtls protocols.

0.4.0.2 - 2026-03-17

Changed

• Dependency bounds.

0.4.0.1 - 2026-03-17

Added

• Optional liquid Cabal flag (--flag haal:liquid) to enable LiquidHaskell verification without requiring it as a dependency for normal builds.

Verified

• Haal.BlackBox: walk produces outputs of length equal to the input length.
• Haal.Learning.LMstar: ObservationTable invariant that all entries in mappingT map to non-empty output lists, preserved across updateMap, makeConsistent, makeClosed, and initializeOT.

0.4.0.0 - 2026-03-16

Changed

• Changed the types of oracles' constructors from <Oracle> to Either String <Oracle> where String is an error message indicating invalid values to <OracleConfig>. Now, for example, instead of oracle = mkWMethod (WMethodConfig 2), one should either pattern match with case or do oracle = either error id (mkWMethod (WMethodConfig 2)).

0.3.0.0 - 2026-03-11

Changed

• SUL typeclass no longer takes i and o as class parameters; they are now universally quantified in the method signatures. Instances should drop i o from their instance heads: instance SUL MyType IO instead of instance SUL MyType IO Input Output.
• Automaton typeclass likewise drops i and o from its class head. All constraint occurrences (Automaton aut s i o) become (Automaton aut s).

0.2.0.0 - 2026-03-05

Added

• stepPure, walkPure, resetPure exported from Haal.BlackBox
• Config record types for all equivalence oracles: WMethodConfig, WpMethodConfig, RandomWalkConfig, RandomWordsConfig, RandomWMethodConfig, RandomWpMethodConfig
• mkCombinedOracle smart constructor for CombinedOracle
• randomWordsConfig accessor for RandomWords
• mealyDelta, mealyLambda as explicit named exports from Haal.Automaton.MealyAutomaton

Changed

• All oracle constructors now take a Config record instead of positional arguments: mkWMethod :: WMethodConfig -> WMethod, mkWpMethod :: WpMethodConfig -> WpMethod, etc.
• mkRandomWMethod and mkRandomWpMethod now take a Config record instead of positional arguments (also fixes an argument-order bug in the old interface)

Removed

• mealyStep from Haal.Automaton.MealyAutomaton; use stepPure from Haal.BlackBox
• mooreStep from Haal.Automaton.MooreAutomaton; use stepPure from Haal.BlackBox
• Raw constructor exports (MealyAutomaton (..), WMethod (..), WpMethod (..), RandomWalk (..), RandomWords (..), CombinedOracle (..), LMstar (..)); use the corresponding mk-prefixed smart constructors instead

0.1.0.0 - 2025-12-02

• Initial release of haal.
  • Support for Mealy Automata and DFAs.
  • One learner for Mealy Automata and DFAs with 2 configurations.
    • LStar.
    • LPlus.
  • Basic equivalence oracles.
  • Examples that showcase usage of the library.