package mazeppa

Changelog

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 Semantic Versioning.

unreleased

0.7.2 - 2025-12-05

Fixed

• Remove List.is_empty usage because is is only supported on versions 5.1 or higher.

0.7.1 - 2025-12-05

Changed

• An integer x embeds in integer y of the same type iff x is less than or equal to y (issue https://github.com/hirrolot/mazeppa/issues/35).
• Enhance horizontal configuration analysis by checking calls that match on all neutrals, not just variables (issue https://github.com/hirrolot/mazeppa/issues/33).
• Emit run-time panics on invalid program states instead of failing (issue https://github.com/hirrolot/mazeppa/issues/34).
• Implement a more reasonable pretty-printer for output code.
• Only require bisect_ppx and alcotest for testing, not for production builds.

Fixed

• Properly special-case pretty printing of FFI calls: call "mz_ffi_xxx" (...).
• A non-termination scenario of endless whistling and splitting (issue https://github.com/hirrolot/mazeppa/issues/36).

0.7.0 - 2025-11-22

Fixed

• The incorrect version number of the previous release to account for the backwards-incompatible change.

0.6.3 - 2025-11-22

Removed

• The --print-gc-stats flag for the run and eval commands (no longer needed) [BC].

0.6.2 - 2025-11-22

Fixed

• Use proper spacing for switch-statements in C output: switch (x) not switch(x).

0.6.1 - 2025-11-22

Fixed

• Treat FFI calls as neutrals (issue https://github.com/hirrolot/mazeppa/issues/31).

0.6.0 - 2025-10-29

Added

• C FFI support [BC].

  • We introduced the call keyword, for which reason this change is not backwards-compatible.

Changed

• Set the exact checked_oint version requirement to 1.0.0.

Fixed

• Emit errors for primitive operations with an incorrect number of arguments.

0.5.2 - 2025-04-08

Changed

• Set the minimum checked_oint version requirement to 0.5.0.

  • Internally, this enables proper integer conversion instead of going to string and parsing it back.

0.5.1 - 2025-03-27

Fixed

• The outdated version number in the CLI output.

0.5.0 - 2025-03-23

Added

• The Symbol.freshen function that generates a fresh symbol according to a given predicate.
• The Raw_term.let' shortcut function.

Changed

• Do not share syntactically equal arguments during postprocessing.
• Preserve names of global unknowns and constructor parameters in residual code (refreshing if necessary).
• Use a more lenient WQO for strings: set(s1) = set(s2) /\ length(s1) <= length(s2).

• Set the minimum checked_oint version requirement to 0.4.1.

  • This fixes compilation on Fedora Linux, openSUSE, FreeBSD, and Oracle Linux.

Fixed

• Do not simplify /(x, 0) and %(x, 0) to avoid incorrect panic messages (issue https://github.com/hirrolot/mazeppa/issues/25).
• Hide empty reduction paths in CLI error messages (issue https://github.com/hirrolot/mazeppa/issues/27).
• Do not overshadow user-specified symbols during residualization (issue https://github.com/hirrolot/mazeppa/issues/28).
• Perform correct variable shadowing in C output via extra scoping (issue https://github.com/hirrolot/mazeppa/issues/29).

0.4.3 - 2024-11-11

Changed

• Set the minimum checked_oint version requirement to 0.3.0.

0.4.2 - 2024-10-19

Changed

• Do not extract operands from calls to primitive operations like + (issue https://github.com/hirrolot/mazeppa/issues/24).

0.4.1 - 2024-10-18

Fixed

• Set the minimum menhir version requirement to 20180905.

0.4.0 - 2024-10-17

Changed

• Preserve the order of built-in panics in residual programs (issue https://github.com/hirrolot/mazeppa/issues/23).

  • Algebraic simplification now requires operands to be either variables or constants, not compounds.

• Eliminate let-bindings for "innocent terms" via postprocessing.

  • Innocent terms are variables, integer constants, and zero-arity constructor calls.
• Set the minimum supported OCaml version to 4.14.0.
• Set the minimum checked_oint version requirement to 0.2.1.

Removed

• The function Const.escape_char is no longer public [BC].

0.3.4 - 2024-10-12

Changed

• Reuse predefined thunks for variables standing as constructor arguments.

  • This improves output code size and compilation times when C code generation is used.

0.3.3 - 2024-10-03

Fixed

• Tweak the dependencies in dune-project after trying to publish the package.

0.3.2 - 2024-10-02

Added

• Expose the Gensym module in the public API, which was previously private to users.

0.3.1 - 2024-09-23

Added

• The Mazeppa-to-C translator via the new translate command (issue https://github.com/hirrolot/mazeppa/issues/1).
• The translate_to_c and mazeppa_h API functions.

0.3.0 - 2024-08-16

Added

• The --print-gc-stats flag for run and eval to observe total memory usage.
• Expose the check function in the public API.

Changed

• Optimize homeomorphic embedding by maintaining a local result cache (issue https://github.com/hirrolot/mazeppa/issues/20).

• Other homeomorphic embedding performance tweaks (issue https://github.com/hirrolot/mazeppa/issues/17).

  • In particular, utilize Weak hash consing while building function bodies.
• Rename the functions 1) Symbol.kind to op_kind, 2) Symbol.is_lazy to is_lazy_op [BC].
• Hide the middles of long reduction paths with (N more...) (issue https://github.com/hirrolot/mazeppa/issues/21).

Fixed

• Evaluation of built-in panics raising an exception (issue https://github.com/hirrolot/mazeppa/issues/22).

Removed

• The function Raw_term.is_immediate is no longer public [BC].

0.2.0 - 2024-08-03

Added

• Propagate positive information for inequality (!=) tests (issue https://github.com/hirrolot/mazeppa/issues/7).

• More simplification rules:

  • op(op(t)) -> op(t), where op is one of u8, u16, u32, u64, u128, i8, i16, i32, i64, i128, string.
  • /(0, t) -> 0
  • |(t, all ones), |(all ones, t) -> all ones
  • &(t, all ones), &(all ones, t) -> t
• Add the check command to the CLI for checking program well-formedness (issue https://github.com/hirrolot/mazeppa/issues/18).
• Expose the Symbol.list function in the public API.

Changed

• Only whistle on terms with equal redex signatures (issues https://github.com/hirrolot/mazeppa/issues/9, https://github.com/hirrolot/mazeppa/issues/11).
• Only whistle on equal integers (issue https://github.com/hirrolot/mazeppa/issues/12).
• Rebuild as less terms as possible when substituting contractions (issue https://github.com/hirrolot/mazeppa/issues/14).
• Optimize homeomorphic embedding by storing term sizes (issue https://github.com/hirrolot/mazeppa/issues/17).

Fixed

• Internal compiler errors when analyzing T/F-patterns during driving. Instead, show proper error messages (issue https://github.com/hirrolot/mazeppa/issues/6).
• Incorrect exception backtraces (issue https://github.com/hirrolot/mazeppa/issues/8).
• Require constructors to be used consistently [BC] (issue https://github.com/hirrolot/mazeppa/issues/10).

0.1.2 - 2024-07-20

Added

• Function productivity analysis for preventing unneeded specializations (issue https://github.com/hirrolot/mazeppa/issues/2).
• pattern_to_string and pattern_verbatim (Raw_term).

Changed

• Only check for renamings instead of arbitrary safe instances when analyzing configurations horizontally.
• Do not emit 1) linear let-bindings for redexes, 2) unused let-bindings for immediate terms.

0.1.1 - 2024-07-15

Added

• mazeppa eval: A built-in evaluator for the Mazeppa language (issue https://github.com/hirrolot/mazeppa/issues/5).
• Expose the Const module in the public API.

Changed

• The following simplification rules are upgraded to handle any values instead of variables only:

  • *(x, 0), *(0, x) -> 0
  • &(x, 0), &(0, x) -> 0
  • %(x, 1) -> 0
  • /(x, 0), %(x, 0) -> out of range
  • |(x, x), &(x, x) -> x
  • =(x, x), >=(x, x), <=(x, x) -> T()
  • !=(x, x), >(x, x), <(x, x) -> F()

0.1.0 - 2024-07-11

Added

• The Mazeppa supercompiler.