Release Notes

This document lists major changes across releases.

Added in version 1.0: (June 26, 2025)

• New command fandango talk for checking outputs and testing protocols (beta).

• Much faster parser for .fan files, using C++ code.

• Support for regular expressions for producing and parsing.

• Support for soft constraints and optimization (maximizing / minimizing).

• Using */** expressions for Python-style quantifiers is now operational.

• f-strings in Python code are now supported.

• Support for libfuzzer harnesses.

• New command fandango convert for converting ANTLR and other input specifications.

• New command fandango clear-cache for clearing the parser cache.

• Improved bit parser.

• Lots of minor and major improvements and bug fixes across the board.

Changed in version 1.0:

• We now apply Python end-of-line rules to grammar parsing. End continuation lines with \ or use parentheses.

• Fuzzing by default is now “infinite”, producing results until stopped. Specify -n N to obtain N outputs.

Added in version 0.8: (April 10, 2025)

• First public beta release.

• fandango fuzz and fandango parse commands.