praxis-parser

Lexer and parser for the Praxis language.

• lex turns source text into a lossless token stream, trivia included, plus T0xx diagnostics.
• parse runs the lexer and then a recursive-descent parser with a Pratt expression layer, producing a rowan-backed lossless tree plus P0xx diagnostics.

Parsing does not stop at the first error, and the tree it returns is complete whether or not one was reported: an editor asking for hover types in a file with a syntax error still gets a tree to ask about. Because trivia is retained, a code action can rewrite one span and leave every comment where the author put it.

praxis-ast is the typed view over the result; praxis-syntax owns the node vocabulary.

Part of Praxis

Praxis is a small, statically typed, garbage-collected language for Advent of Code-style puzzles: the input parser is part of the language, types are inferred rather than written, and a program that falls over hands you its state instead of a stack trace.

To use the language, install praxis-cli — it provides the praxis binary. The repository has the book, the design document and the decision records.

This crate is one stage of that compiler, published so the pipeline is inspectable and so praxis-cli can be built from the registry. Its API tracks what the compiler needs and is not a stable platform for outside consumers.

Praxis was written with large language models against a human design. The repository's README says what that means for the license.

Licensed under either of Apache License 2.0 or the MIT license, at your option.