SH-B: Production Rust realization closure now

src/v2/compiler/emit_produced.dag

@@ -3,11 +3,13 @@ module v2.compiler.emit_produced
 import v2.compiler.emit_module { emit_module_decl_separator }
 import v2.compiler.translate { target_serialize_bodied_arrow_from_model }
 import v2.compiler.target_carriers { target_source_medium }
-import v2.extdeps.languages.rust {
-  rust_produced_decl_target,
-  rust_signature_with_open_from_decl
+import v2.std.compilers.target_model {
+  ProducedDeclUnwired,
+  ProducedDeclWired,
+  TargetModel,
+  render_target_text,
+  target_model_with_produced_scaffold
 }
-import v2.std.compilers.target_model { TargetModel, render_target_text }
 import extdeps.communication.medium { Medium }
 import v2.std.collection { Absent, List, Present, list_at_optional }
 import v2.std.algebra { fold_list, list_append }
@@ -22,7 +24,8 @@ import v2.std.diagnostic {
   Unavailable,
   bind_outcome,
   diagnostics_singleton,
-  node_locus
+  node_locus,
+  outcome_rejected
 }
 import v2.std.node { Conj, Named, Node, Positional, Symbol, TypeNode }
 import v2.std.text { String }
@@ -65,7 +68,7 @@ fn emit_produced_decl_inner_arrow(decl: Node) -> Outcome<Node> {
   }
 }
 
-fn emit_produced_decl_rust_with_target(
+fn emit_produced_decl_with_target(
   decl: Node,
   target: TargetModel
 ) -> Outcome<Medium<String>> {
@@ -82,21 +85,47 @@ fn emit_produced_decl_rust_with_target(
   )
 }
 
-fn emit_produced_decl_rust(decl: Node) -> Outcome<Medium<String>> {
-  bind_outcome(
-    o: rust_signature_with_open_from_decl(decl: decl),
-    f: fn(signature) {
-      emit_produced_decl_rust_with_target(
-        decl: decl,
-        target: rust_produced_decl_target(signature_with_open: signature)
+// The compiler asks the TARGET to render the declaration and receives a bodied-arrow
+// scaffold back. It does not know whether the signature leads with a keyword or a
+// return type, which side of a parameter the type sits on, whether a return arrow
+// exists, or how the declaration closes -- all of that is the renderer's. A target
+// that registered no renderer refuses with a typed, located produced_decl_target_unwired:
+// never a widen, never a fabricated default (DESIGN section 5).
+fn emit_produced_decl(decl: Node, target: TargetModel) -> Outcome<Medium<String>> {
+  match target.produced_decl_support {
+    ProducedDeclUnwired =>
+      outcome_rejected(
+        d: emit_produced_decl_diagnostic(reason: ^produced_decl_target_unwired, node: decl)
       )
-    }
-  )
+    ProducedDeclWired {
+      render: render,
+      scaffold_relation_rule_name: rule_name,
+      scaffold_base_row: base_row
+    } =>
+      bind_outcome(
+        o: render(decl),
+        f: fn(scaffold) {
+          emit_produced_decl_with_target(
+            decl: decl,
+            target: target_model_with_produced_scaffold(
+              target: target,
+              rule_name: rule_name,
+              base_row: base_row,
+              scaffold: scaffold
+            )
+          )
+        }
+      )
+  }
 }
 
-fn emit_produced_module_append(partial: String, decl: Node) -> Outcome<String> {
+fn emit_produced_module_append(
+  partial: String,
+  decl: Node,
+  target: TargetModel
+) -> Outcome<String> {
   bind_outcome(
-    o: emit_produced_decl_rust(decl: decl),
+    o: emit_produced_decl(decl: decl, target: target),
     f: fn(medium) {
       Accepted {
         value: list_append(
@@ -109,16 +138,25 @@ fn emit_produced_module_append(partial: String, decl: Node) -> Outcome<String> {
   )
 }
 
-fn emit_produced_module_step(acc: Outcome<String>, decl: Node) -> Outcome<String> {
-  bind_outcome(o: acc, f: fn(partial) { emit_produced_module_append(partial: partial, decl: decl) })
+fn emit_produced_module_step(
+  acc: Outcome<String>,
+  decl: Node,
+  target: TargetModel
+) -> Outcome<String> {
+  bind_outcome(
+    o: acc,
+    f: fn(partial) {
+      emit_produced_module_append(partial: partial, decl: decl, target: target)
+    }
+  )
 }
 
-fn emit_produced_module_rust(decls: List<Node>, target: TargetModel) -> Outcome<Medium<String>> {
+fn emit_produced_module(decls: List<Node>, target: TargetModel) -> Outcome<Medium<String>> {
   bind_outcome(
     o: fold_list(
       xs: decls,
       empty: Accepted { value: Empty, diagnostics: None },
-      cons: fn(acc, decl) { emit_produced_module_step(acc: acc, decl: decl) }
+      cons: fn(acc, decl) { emit_produced_module_step(acc: acc, decl: decl, target: target) }
     ),
     f: fn(joined) { target_source_medium(text: joined, target: target) }
   )