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//! # Property lens contract
//!
//! [`VcardPropLens`] ties a property (by type) to its decoded value type, an
//! edit cursor, and the `decode` projection from the generic syntax node onto
//! the type.
//!
//! The wire name comes from its [`VcardPropSpec::KIND`] supertrait, so the two
//! stay in sync; each property implements it on the marker in its own module.
use crate::{
prop::spec::VcardPropSpec,
tree::{codec::VcardCodec, line::VcardLine},
version::VcardVersion,
};
/// A property identified by type: its decoded value type, edit cursor, and the
/// `decode` projection from the generic syntax node onto the type. The wire
/// name comes from its [`VcardPropSpec::KIND`] (a supertrait), so the two stay
/// in sync.
pub trait VcardPropLens: VcardPropSpec {
/// The decoded value type, borrowing the syntax node for reads. Its
/// [`VcardCodec`] impl is what the default `decode` delegates to.
type Target<'v>: VcardCodec<'v>;
/// The typed edit cursor over a content line.
type Cursor<'c, 'a>
where
'a: 'c;
/// Project a content line onto the decoded type.
///
/// The default ignores the version and decodes the node through the
/// target's [`VcardCodec`]. The lenses whose value shape is
/// version-specific (`GEO`, the binary props) override it.
fn decode<'v>(line: &'v VcardLine<'_>, _version: VcardVersion) -> Self::Target<'v> {
<Self::Target<'v> as VcardCodec<'v>>::decode(&line.value)
}
/// Wrap a content line in the typed cursor for in-place editing.
fn cursor<'c, 'a>(line: &'c mut VcardLine<'a>) -> Self::Cursor<'c, 'a>;
}