xolsh - hslox

# Build
cabal build xolsh-exe
# Run a lox file
cabal run xolsh-exe -- file.lox
# Run interactive lox repl
cabal run xolsh-exe

A complete Haskell tree-walking implementation of the lox programming language (jlox) from the Crafting Interpreters Book. It fully passes the jlox test suite and has an online playground.

The code style of the interpreter is mostly a port/adaptation of the original java implementation, with a more idiomatic Haskell style where possible.

• Areas for improvement:
  • Try to write a one-pass scanning-parsing step with parser combinators (w/flatparse) to compare performance.
  • Optimize variable & field access (through vectors?).
  • A rewrite with an effect system would probably give many benefits, specially to the code style.