Haskell library for parsing and rendering A2ML (Attested Markup Language) — attestation-native markup carrying trust metadata, cryptographic attestation fields, and provenance information.

Overview

a2ml-haskell provides a purely functional parser and renderer over Text:

• Data.A2ML.Parser — `parseA2ML
  Text → Either ParseError Document`. Line-oriented, no regex, no mutable state. Recognises headings, multi-line directive blocks (@name: … @end), bullet lists, and inline formatting.

• Data.A2ML.Renderer — serialises a Document back to canonical A2ML.

• Data.A2ML.Types — Document, Block, Inline, DirectiveName (typed sum: DirAbstract, DirRefs, DirAttestation, DirMeta, DirCustom Text), Attestation, TrustLevel, Manifest, Reference.

The Haskell variant uses richer directive syntax than a2ml-rs: directives are multi-line @name: … @end blocks (not single-line @name value pairs).

Attestation Model

The Attestation type carries:

• attestationSigner — identity of the signing agent or person

• attestationAlgorithm — e.g. "ed25519" or "sha256"

• attestationSignature — hex or base64 signature (opaque, not verified here)

• attestationTimestamp — optional ISO-8601 timestamp

TrustLevel encodes attestor count and independence: Unsigned → SelfAttested → ThirdPartyAttested → MultiAttested.

Manifest aggregates title, author, version, SPDX license, overall trust level, and the full attestation list — the entry point for provenance inspection.

Building

cabal build
cabal test

Related

• a2ml-rs — Rust implementation

• pandoc-a2ml — Pandoc Lua reader/writer

License

MPL-2.0. See LICENSE.