Crate vize_l2 

L2 - the Davinci semantic IR (codename Disegno): the pivot stage and the primary consumer surface.

Experimental: the stage API may change in any alpha release; record intentional breaking changes in the release notes.

Named after Leonardo’s disegno: the drawing that carries the idea, independent of the material it is later executed in.

L2 is the normalized, input-neutral representation of UI semantics (docs/davinci/architecture.md, “L2 — Disegno”). Vue templates, JSX and pug all lower into the same op family; whatever is genuinely Vue-specific stays a vue.* dialect op instead of shaping the core. The Vue template lowering into this family is vize_l1_to_l2 (codename Ricalco; P2-8); this crate holds the type family, its folio page, the invariants that are enforceable by construction, and the verifier for the ones that are not:

• op — the op enums (op::Op, op::BindingOp) and their payload types, arena-resident and Drop-free by construction through vize_l0::{Box, Vec} (whose const assertion rejects Drop payloads; P1-10 measured it catching two real violations).
• expr — expr::ExprRef, the expression reference: retained JS AST, foreign dialect (type-only until phase 6), or the classified escape with pessimal documented semantics (P2-5b’s decision; record in docs/davinci/plan/phase-2-records/p2-5b.md).
• dump — crate::dump::Page, the L2 stage dump (docs/davinci/plan/folio-format.md, “Disegno page”).
• verify — the between-pass invariant checks (P2-6), debug/CI only: local in the GHC -dcore-lint sense, and never in a release build.
• scope / provenance — the side-table vocabulary lowerings attach beside the tree (P2-8): hygiene scope tags on binding-introducing ops, and before/after provenance records that survive failure. Neutral types here so every input dialect’s lowering (Vue today, JSX at P2-16) speaks the same facts.
• analysis — backend-neutral computations and canonical fact schemas over L2 control and retained expressions. Dialect lowering crates may adapt their transitional owners to these analyses without owning the product vocabulary.

The crate is no_std + alloc from birth so L2 artifacts print and parse on any target (wasm32-wasip2 included; P2-14 makes that lane required).

Modules

analysis

Backend-neutral analyses over canonical L2 artifacts.

artifact

Native canonical L2 ownership, independent of a dialect legalizer.

dump

The L2 folio: the stage dump.

expr

The L2 expression reference (P2-5b): ExprRef and its payload family.

file

File-local semantic facts sealed with their actual canonical artifact.

lang

Language-specific L2 expression semantics.

op

The L2 op family: one concrete typed enum per position, never a uniform Operation structure (docs/davinci/architecture.md, “What we take from MLIR, and what we refuse”).

provenance

Lowering provenance: before/after pairs per lowering decision, surviving failure (P2-8).

resolution

Checked identifier uses from an already retained expression AST.

scope

Hygiene scope facts: the side-table vocabulary for binding-introducing ops (P2-8).

summary

The per-SFC summary (P5-2) — one component’s GHC .hi interface.

verify

The L2 verifier: local invariant checks between passes, debug/CI only.

walk

The page-order re-derivation walk the L2 passes share.