Module codec 

Available on crate feature parser only.

Codec

The bytes-to-model bridge, in both directions and at both levels. It is the only part of crate::tree that consults the card version.

decode projects a raw syntax tree onto the decoded model and encode projects it back; that is the structural level. Underneath, the value-string level: escape and unescape apply and resolve the RFC 5545 3.3.11 value escapes (keyed by the mode Escaper). The structural encoders and decoders run every value leaf through those. Content transfer encodings (QUOTED-PRINTABLE, BASE64) and CHARSET are never resolved here: the core transforms no content, leaving that to the opt-in feature helpers.

The per-value-type projection is the Codec trait. One impl per value type lives under crate::tree::value, mirroring the model’s value/, so each value’s codec is written exactly once; both the structural dispatch and the per-property lenses go through it.

Modules

decode

Decode (syntax to model)

encode

Encode (model to syntax)

escape

Escape (write codec)

mode

Escaping mode

unescape

Unescape (read codec)

Traits

Codec

How a decoded value type projects to and from a syntax node: decode reads it from a node (its escaper carries the mode), encode writes it back, escaping every leaf with the given Escaper and stamping it on the node. The escaper is symmetric across the two directions: decode reads it off the incoming node, encode receives the target mode and applies it (the decoded value itself is escaper-agnostic clean text).