[dannote]

For vize 0.17.0. Breaking: Vize.vapor_split/1 is replaced by Vize.split_template/2.

Why

vapor_split built the split from Vapor's generated template HTML. A hand-rolled tag scanner in html_inject.rs located each element in that HTML and matched it to the IR through child/next offsets. Each bug fixed in it so far was the scanner and the IR disagreeing:

• slots dropped after text nodes (0.16.1);
• components placed before earlier siblings;
• a root v-if rendered twice;
• implicit default slot content lost beside a named <template #x>.

Vize already has the right input. vize_l2, its semantic IR, is the representation Vize's SSR compiler builds its string plan from. It has elements, components, text, interpolations, v-if, v-for and slot outlets, with static attributes and typed bindings in authored order, and a source span on every op.

What changed

• split_template/2 lowers the template with vize_l1 and vize_l1_to_l2::lower, then walks the L2 ops, printing static HTML and emitting a slot for everything that depends on data.
• html_inject.rs, vapor_split.rs and its marker splicing are gone.
• Escaping: entities are decoded with Vize's own decode_ssr_static_text and decode_html_attribute_entities, and escaped with html-escape.
• New slot shapes (see the guide's "Splitting templates" section):
  • Expressions are source strings, and every slot has a :position.
  • An :attr slot is a whole attribute, so a renderer can leave it out for null and false boolean attributes, as Vue does. A static attribute of the same name comes with it.
  • Components carry their props, events, and the content of each slot. <slot> outlets are slots.
  • v-show, v-model on <input>/<textarea>, v-html, v-text, v-bind objects and dynamic attribute names are slots.
  • Events and v-models are :on/:model bindings with where their element's start tag ends.
• root_attrs: true: gathers a component template's root element attributes into one slot, for fallthrough attribute merging.
• Errors:
  • Errors are Vize.Error with a positioned Vize.Diagnostic each, such as 1:7: can't parse the expression \a +`, and the error message lists them. Warnings, such as custom directives, are in the split's :diagnostics`.
  • Vize.Diagnostic gains :severity.
  • Vize.Diagnostic.to_code_diagnostic/2 converts a diagnostic to Elixir's Code.diagnostic shape for a file, offset to where the template starts in it.
• RustQ atom generation: atoms from raw identifiers such as atoms::r#if() are deduplicated against {:if, "if"} declarations.

Verification

• VIZE_EX_BUILD=1 mix ci passes: credo, ex_dna, reach, dialyzer, clippy, and 130 tests.
• test/vize/split_template_test.exs covers each slot kind, entity round-tripping, attribute merging, slot placement among siblings, component slots including v-slot on the component, root_attrs, and diagnostics with positions.
• PhoenixVapor's playground branch renders its test suite (307 tests, e2e included) and demo (14 e2e tests) on this split.