ToxicParser is an error-tolerant Elixir parser that integrates with the Toxic streaming lexer and emits an event log suitable for AST/CST/environment builders. Phase 0 focuses on contracts and conformance harnessing; the current implementation defers to Code.string_to_quoted_with_comments/2 while locking the public surface.
:strict(default): lexer/parser errors are fatal and returned as{:error, %ToxicParser.Result{}}.:tolerant: lexer/parser errors are collected in diagnostics and returned alongside the best-effort result; no exception is raised.- Tolerant mode downgrades lexer fatals into diagnostics and emits synthetic error tokens; strict mode stops on the first lexer error and never synthesizes delimiters.
- Newline counts from
eol/;tokens are preserved on the normalized:eoetoken for layout-sensitive operators.
See PHASE0_CONTRACTS.md for detailed behavior, event log schema, metadata policy, and builder contracts.
ToxicParser.parse_string/2ToxicParser.parse_file/2ToxicParser.parse/2(alias ofparse_string/2)
All entry points return {:ok, %ToxicParser.Result{}} on success or {:error, %Result{}} in strict mode failures.
ToxicParser.Conformance.compare/2 runs the parser in strict and tolerant modes and returns the reference AST/comments from Elixir's parser for CI assertions. ExUnit tests exercise this harness and keep NONTERMINALS_GPT.md in sync via ToxicParser.Nonterminals.
- Run
mix testto execute the conformance harness and contract checks. NONTERMINALS_GPT.mdis treated as the canonical nonterminal mapping and is loaded at compile time.- Set
TOXIC_PATHto point at a checkout of the Toxic lexer when running CI (see.github/workflows/ci.yml); falls back to/Users/lukaszsamson/claude_fun/toxicfor local development. - Phase 3 adds Pratt skeleton and precedence table; Phase 4 introduces a minimal grammar dispatcher. Phase 5 begins call/identifier scaffolding with paren call parsing and identifier classification. Public API still delegates to
Code.string_to_quoted_with_comments/2until parser completeness.
If available in Hex, the package can be installed
by adding toxic_parser to your list of dependencies in mix.exs:
def deps do
[
{:toxic_parser, "~> 0.1.0"}
]
end