Enum MatrixTarget 

pub enum MatrixTarget {
    Version,
    Profile,
    ChartRef,
}

Closed-set typed identifier for the @-prefixed magic targets a MatrixAxis::path can write into on the base EphemeralSpec — the three reachable aplicacao-field write targets (Self::Version → aplicacao.version, Self::Profile → aplicacao.profile, Self::ChartRef → aplicacao.chart_ref) — as a Rust enum, so the three-way (path-string, aplicacao-field) pairing binds at ONE site on the typed algebra rather than at three byte-identical inline arms in [apply_axis].

Pre-lift the magic-target dispatch lived as three arms in [apply_axis], each opening its own val.as_str().to_string() → field = … skeleton paired with its own &'static str literal arm label. The (path-literal, aplicacao-field) pairing was load-bearing across three sites yet only enforced by call-site discipline — a regression that swapped two assignment targets (e.g. routed "@version" to chart_ref) type-checked but silently mis-applied every operator’s matrix sweep. Post-lift the pairing binds at ONE typed projection (Self::apply) the substrate’s invariant relies on: rustc’s closed-set match across Self enforces that every variant has exactly one apply arm and exactly one Self::marker arm, and the bidirectional contract from_path(t.marker()) == Some(t) makes the decode + canonical-marker round-trip a TYPE rather than three string literals scattered across the file.

Adding a fourth magic-target (e.g. @release-name → aplicacao.release_name, @target-namespace → aplicacao.target_namespace) extends the enum AND the three projection arms (Self::from_path, Self::marker, Self::apply) in lockstep — rustc binds the extension through exhaustiveness over the closed enum so a partial extension that forgets ONE projection becomes a compile error rather than a runtime drift.

Sibling closed-set lift to tatara-lisp’s QuoteForm (four-of-four homoiconic prefix-wrappers), UnquoteForm (two-of-four template- marker subset), MacroDefHead (two-of-two macro-definition heads), and CompilerSpecIoStage (disk-persistence surface) closed-set algebras: those enums key their respective dispatch / projection variants on a typed identity carried inside the variant; this enum keys the three reachable matrix-axis aplicacao-field write targets on a typed marker identity.

Theory anchor: THEORY.md §V.1 — knowable platform; the closed set of @-prefixed magic targets becomes a TYPE rather than three &'static str literals scattered across [apply_axis]. A typo in any arm becomes a compile error against the typed projection. THEORY.md §VI.1 — generation over composition; the (path-literal, aplicacao-field) pairing appeared at three arms — past the ≥2 PRIME-DIRECTIVE trigger once the structural shape is named. THEORY.md §II.1 invariant 1 — typed entry; the matrix-axis path-string to typed-target decoding IS the typed-entry gate at the MatrixAxis::path boundary, and naming the closed-set identity lifts the gate from per-site literal discipline to ONE method the substrate’s diagnostic promotions hang off of.

Variants

Version

@version → aplicacao.version.

Profile

@profile → aplicacao.profile.

ChartRef

@chart-ref → aplicacao.chart_ref.

Implementations

impl MatrixTarget

pub const ALL: [Self; 3]

The closed set of magic targets — single source of truth that drives the marker / Display / from_path triad AND the per-variant apply arm. Adding a fourth magic target (e.g. @release-name → aplicacao.release_name, @target-namespace → aplicacao.target_namespace) lands at one ALL entry + one marker arm + one apply arm, exhaustively checked by the compiler (the [Self; 3] array literal forces the arity) AND by the per-variant bidirection + apply truth-table tests below. Sibling closed-set lift to every other ALL-keyed enum in this crate including crate::phase::ProcessPhase::ALL, crate::intent::IntentKind::ALL, crate::signal::ProcessSignal::ALL, crate::boundary::ConditionKind::ALL, crate::lifetime::TeardownPolicy::ALL, and crate::classification::SubstrateType::ALL; having ONE enumeration site means future LSP-completion, tatara-check magic-target enumeration, and exhaustive bidirection sweeps project through this constant rather than re-listing the variants at every consumer.

pub fn from_path(path: &str) -> Option<Self>

Decode a MatrixAxis::path string into the typed marker, or None for paths that aren’t reserved @-prefixed magic targets (they fall through to [overlay_at_path] semantics inside [apply_axis]). Closed-set dual of Self::marker: for every variant t, from_path(t.marker()) == Some(t). Lifted onto a linear search across Self::ALL keyed on Self::marker so the canonical @-prefixed string literals live at ONE site (the marker arms) rather than at TWO sites (a from_path arm AND a marker arm per variant) — adding a fourth magic target extends only ALL + the marker arm + the apply arm, NOT a third per-variant literal site.

pub fn marker(self) -> &'static str

Canonical &'static str marker — the @-prefixed path literal each variant decodes from. Bidirectional dual of Self::from_path: for every variant t, from_path(t.marker()) == Some(t). The &'static str lifetime lets consumers (axis-path docstrings, future tatara-check typed-target enumerators, future LSP completion lists) project through this method without an allocation, parallel to how tatara_lisp’s QuoteForm::prefix / UnquoteForm::marker / CompilerSpecIoStage::operation project their closed-set surfaces.

pub fn apply(self, spec: &mut EphemeralSpec, val: &Value)

Apply a string value into the targeted [AplicacaoIntent] field on spec.aplicacao. Non-string values are silently ignored — matching the pre-lift [apply_axis] posture (the magic-target arms only acted when val.as_str() succeeded; non-string axis values for a magic target are dropped, NOT routed to the overlay). The (variant, field-assignment) pairing binds at ONE match arm rather than three byte-identical sites — a regression that drifts ONE arm’s field target (e.g. routes Self::Version to chart_ref) becomes a compile error against the typed projection.

Trait Implementations

impl Clone for MatrixTarget

fn clone(&self) -> MatrixTarget

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for MatrixTarget

impl Debug for MatrixTarget

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for MatrixTarget

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Project the variant through Self::marker — the canonical @-prefixed path literal each variant decodes from. Pinned by matrix_target_display_matches_marker_for_every_variant so a future Display impl can’t drift from the canonical marker (the posture every sibling-closed-set Display in this crate carries, e.g. crate::lifetime_clock::TerminateReason, crate::classification::Arity).

impl Eq for MatrixTarget

impl PartialEq for MatrixTarget

fn eq(&self, other: &MatrixTarget) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for MatrixTarget