UDA vocabulary

The previous pages introduce UDAs as they appear in Svelte. This page is the vocabulary compile!() actually walks, in one place, so a printed file can be read without flipping back. These are libwasm UDAs (types.d), not D @property. Bare @prop with no name is not a legal UDA; the template is struct prop(alias prop_name).

mixin NodeDef!"tag" is the NamedNode. @child marks a field as a child component; getChildren finds it and compile! recurses. @prop / @attr / @style are the DOM property, attribute, and class on this NamedNode. Pointer @prop / @attr dereference if non-null — that is how an @inject!"msg" string* can feed the same named property. @callback!"click" is the DOM event to method. mixin Slot!("name", Params) is an EventEmitter; empty-Params add appends. this.emit(slot, args) calls those callbacks, including address-callbacks with cast(size_t)(&t).

@connect!"a.b" is t.a.b.add(&method). The string is a D member path; dots stay dots. @connect!("list.items","link.clicker") is the list form: t.list.items.link_clicker.add(&method). The second path’s dots become underscores because ArrayItemEvents!T declares Slots on the array with underscores. The method’s first parameter must be size_t. @inject!"parentField" is a single identifier, not a dotted path; compile! searches the parent tuple for a member of that name and, if the child field is a pointer, stores &parent.host.

@visible!"child" skips or remounts that @child via setVisible. {#if ident} prints this UDA on bool ident of the owner. @entering!"/path" is libwasm URLRouter, not a DOM UDA. @connect and @inject paths are identifiers on the compiled struct. They are not SvelteKit file paths and not CSS selectors. A connect string that looks like .admin-nav is a mistake, not a feature.