fix(rust): map a tuple element by element

.trinity/seals/Explainability.json

@@ -1,6 +1,6 @@
 {
   "gen_hash_c": "sha256:952caf75701c86102f5920523badff0aff5810bf66fac7806c0adc63d2266169",
-  "gen_hash_rust": "sha256:e059173c75a58fe21330468a2d2a482ca8743039964eb931ece9b21de9136f98",
+  "gen_hash_rust": "sha256:6d875be3225c359d230ae0bdd7b5b32461ee45f7803789a6d9a307aa35eb5746",
   "gen_hash_verilog": "sha256:f0f9fca4fd8795607c9ac572ef510888f9467aff2f64eadf8725b94993e205df",
   "gen_hash_zig": "sha256:f52e5c26de65c941c91654b1cfb4ccaed8938f99b756db204f28a764fb149291",
   "module": "Explainability",

.trinity/seals/NotebookLM.json

@@ -1,6 +1,6 @@
 {
   "gen_hash_c": "sha256:1363497601bffd09dd3ee2c619f834af65869e1e4f2ed21dcc9a03ebbec9b21c",
-  "gen_hash_rust": "sha256:121bd3164607487cc77b79c5604573fc8bfa4b1a39aa1926f53bfa4247c1dc2c",
+  "gen_hash_rust": "sha256:a0b1a594713925c0c571351b89a61f6b6a0f8adc20ffcef8f926037ff4d03b43",
   "gen_hash_verilog": "sha256:7716f39dc3d0baf658917208a7c294da3ed66d8d849778e3a0d170e7083115b4",
   "gen_hash_zig": "sha256:534abb99380c2bc0decab8ee239edaac260e956b20891b17728a337b40ba104c",
   "module": "NotebookLM",

.trinity/seals/ProofTrace.json

@@ -1,6 +1,6 @@
 {
   "gen_hash_c": "sha256:05385a9de9099e0a596ac23cb2231fdca952db8e92df3681479a44aa12026d09",
-  "gen_hash_rust": "sha256:0574a717a935eeb52e81ec955b24f7d36ddae62bae3b86ac4ac7a27a6847e467",
+  "gen_hash_rust": "sha256:4abb3379bc73d56f926b4605e8a1cc9a97bc4d9979a95549792111aca90ca460",
   "gen_hash_verilog": "sha256:277e8f3d888b436b3386fa512f275d3994fcc40b711df9bb60d10815457e9a1d",
   "gen_hash_zig": "sha256:85ca85b32a903b330cd0fd1b543c3ba5eefb4f91d83528baaece0cd33d8d331c",
   "module": "ProofTrace",

.trinity/seals/ar_Explainability.json

@@ -1,11 +1,11 @@
 {
   "gen_hash_c": "sha256:952caf75701c86102f5920523badff0aff5810bf66fac7806c0adc63d2266169",
-  "gen_hash_rust": "sha256:e059173c75a58fe21330468a2d2a482ca8743039964eb931ece9b21de9136f98",
+  "gen_hash_rust": "sha256:6d875be3225c359d230ae0bdd7b5b32461ee45f7803789a6d9a307aa35eb5746",
   "gen_hash_verilog": "sha256:f0f9fca4fd8795607c9ac572ef510888f9467aff2f64eadf8725b94993e205df",
   "gen_hash_zig": "sha256:f52e5c26de65c941c91654b1cfb4ccaed8938f99b756db204f28a764fb149291",
   "module": "explainability",
   "ring": 12,
-  "sealed_at": "2026-09-05T19:32:03Z",
+  "sealed_at": "2026-09-06T02:37:18Z",
   "sealed_by": "t27c-bootstrap@0.2.0",
   "spec_hash": "sha256:80e970c2be2a313cfca43bc0bbb20397259952dd2d26af5b1359e1d26ea1a4b3",
   "spec_path": "specs/ar/explainability.t27"

.trinity/seals/ar_ProofTrace.json

@@ -1,6 +1,6 @@
 {
   "gen_hash_c": "sha256:05385a9de9099e0a596ac23cb2231fdca952db8e92df3681479a44aa12026d09",
-  "gen_hash_rust": "sha256:0574a717a935eeb52e81ec955b24f7d36ddae62bae3b86ac4ac7a27a6847e467",
+  "gen_hash_rust": "sha256:4abb3379bc73d56f926b4605e8a1cc9a97bc4d9979a95549792111aca90ca460",
   "gen_hash_verilog": "sha256:277e8f3d888b436b3386fa512f275d3994fcc40b711df9bb60d10815457e9a1d",
   "gen_hash_zig": "sha256:85ca85b32a903b330cd0fd1b543c3ba5eefb4f91d83528baaece0cd33d8d331c",
   "module": "ProofTrace",

.trinity/seals/ar_coa_planning.json

@@ -1,11 +1,11 @@
 {
   "gen_hash_c": "sha256:51034bfe26f2a680c1db02232415a90a4e84420a86c9d4f19602686b9acd5afb",
-  "gen_hash_rust": "sha256:4424f92caae7ab6275bb031f0fa6521e4f3241925c2b1f608370a79d95cfdf3e",
+  "gen_hash_rust": "sha256:d68a3dfc5332bf206443b1befc475940231962e3f1a69f7944daae4006d81f96",
   "gen_hash_verilog": "sha256:29e4a69b72122f9715a543d92d7ee68c8d554ec5b8aefe2f797e9b86406cb8ce",
   "gen_hash_zig": "sha256:f631078ead3dd650ee408409b06bdedaa66f64de0be918128b0caac668b81a33",
   "module": "coa_planning",
   "ring": 12,
-  "sealed_at": "2026-09-05T19:32:03Z",
+  "sealed_at": "2026-09-06T02:37:18Z",
   "sealed_by": "t27c-bootstrap@0.2.0",
   "spec_hash": "sha256:d6b1c23a9296e687435aa23bb3dff4adac3b81e5ff938ac41294d8936a62a7c8",
   "spec_path": "specs/ar/coa_planning.t27"

.trinity/seals/ar_proof_trace.json

@@ -1,11 +1,11 @@
 {
   "gen_hash_c": "sha256:05385a9de9099e0a596ac23cb2231fdca952db8e92df3681479a44aa12026d09",
-  "gen_hash_rust": "sha256:0574a717a935eeb52e81ec955b24f7d36ddae62bae3b86ac4ac7a27a6847e467",
+  "gen_hash_rust": "sha256:4abb3379bc73d56f926b4605e8a1cc9a97bc4d9979a95549792111aca90ca460",
   "gen_hash_verilog": "sha256:277e8f3d888b436b3386fa512f275d3994fcc40b711df9bb60d10815457e9a1d",
   "gen_hash_zig": "sha256:85ca85b32a903b330cd0fd1b543c3ba5eefb4f91d83528baaece0cd33d8d331c",
   "module": "proof_trace",
   "ring": 12,
-  "sealed_at": "2026-09-05T19:32:03Z",
+  "sealed_at": "2026-09-06T02:37:18Z",
   "sealed_by": "t27c-bootstrap@0.2.0",
   "spec_hash": "sha256:2591d4523eed910a4add8ecd6d7f8a33c9883ad3449955ac3c347d9744ab2a04",
   "spec_path": "specs/ar/proof_trace.t27"

.trinity/seals/coa_planning.json

@@ -1,6 +1,6 @@
 {
   "gen_hash_c": "sha256:51034bfe26f2a680c1db02232415a90a4e84420a86c9d4f19602686b9acd5afb",
-  "gen_hash_rust": "sha256:4424f92caae7ab6275bb031f0fa6521e4f3241925c2b1f608370a79d95cfdf3e",
+  "gen_hash_rust": "sha256:d68a3dfc5332bf206443b1befc475940231962e3f1a69f7944daae4006d81f96",
   "gen_hash_verilog": "sha256:29e4a69b72122f9715a543d92d7ee68c8d554ec5b8aefe2f797e9b86406cb8ce",
   "gen_hash_zig": "sha256:f631078ead3dd650ee408409b06bdedaa66f64de0be918128b0caac668b81a33",
   "module": "coa_planning",

.trinity/seals/coder_igla-coder-arch.json

@@ -1,11 +1,11 @@
 {
   "gen_hash_c": "sha256:f0e837bf1d6031326a3a69db7843b208e653a3f527266e01c3b901b41e9efc34",
-  "gen_hash_rust": "sha256:333b47ca7d8c5e82185cc0de3d1273732a52d41b29ea5803be69e015ba711b57",
+  "gen_hash_rust": "sha256:1ba83284c5cda3c45b831b446f4139bc9f15a60d20fd659aacecc859f0b769d9",
   "gen_hash_verilog": "sha256:68ee411594d2a8d1b0df9214fa06102bc4297f3d597e12fef90d8986b86670aa",
   "gen_hash_zig": "sha256:825537b84cf902a2b6ba0e18ce53cb4af39d117aefac808e3ecf8bae4cc09931",
   "module": "igla-coder-arch",
   "ring": 12,
-  "sealed_at": "2026-09-05T11:21:58Z",
+  "sealed_at": "2026-09-06T02:37:19Z",
   "sealed_by": "t27c-bootstrap@0.2.0",
   "spec_hash": "sha256:baafdfb69f57527162bec359e9439edb7e0049f421019912200889abf9386707",
   "spec_path": "specs/igla/coder/arch.t27"

.trinity/seals/memory_NotebookLM.json

@@ -1,11 +1,11 @@
 {
   "gen_hash_c": "sha256:1363497601bffd09dd3ee2c619f834af65869e1e4f2ed21dcc9a03ebbec9b21c",
-  "gen_hash_rust": "sha256:121bd3164607487cc77b79c5604573fc8bfa4b1a39aa1926f53bfa4247c1dc2c",
+  "gen_hash_rust": "sha256:a0b1a594713925c0c571351b89a61f6b6a0f8adc20ffcef8f926037ff4d03b43",
   "gen_hash_verilog": "sha256:7716f39dc3d0baf658917208a7c294da3ed66d8d849778e3a0d170e7083115b4",
   "gen_hash_zig": "sha256:534abb99380c2bc0decab8ee239edaac260e956b20891b17728a337b40ba104c",
   "module": "NotebookLM",
   "ring": 12,
-  "sealed_at": "2026-09-05T20:06:35Z",
+  "sealed_at": "2026-09-06T02:37:19Z",
   "sealed_by": "t27c-bootstrap@0.2.0",
   "spec_hash": "sha256:dc5b054f79d747598c75190379fe4a36400bb27af13dffe06d438f145c1af96f",
   "spec_path": "specs/memory/notebooklm.t27"

.trinity/seals/proof_trace.json

@@ -1,6 +1,6 @@
 {
   "gen_hash_c": "sha256:05385a9de9099e0a596ac23cb2231fdca952db8e92df3681479a44aa12026d09",
-  "gen_hash_rust": "sha256:0574a717a935eeb52e81ec955b24f7d36ddae62bae3b86ac4ac7a27a6847e467",
+  "gen_hash_rust": "sha256:4abb3379bc73d56f926b4605e8a1cc9a97bc4d9979a95549792111aca90ca460",
   "gen_hash_verilog": "sha256:277e8f3d888b436b3386fa512f275d3994fcc40b711df9bb60d10815457e9a1d",
   "gen_hash_zig": "sha256:85ca85b32a903b330cd0fd1b543c3ba5eefb4f91d83528baaece0cd33d8d331c",
   "module": "proof_trace",

.trinity/seals/race_igla-race-cordic.json

@@ -1,11 +1,11 @@
 {
   "gen_hash_c": "sha256:4405e43b030307c596bd7f1d585d2e127fc104209608a64b0b761fdabc05ae7c",
-  "gen_hash_rust": "sha256:bece58ffbc66085d97c01b13110a455de7beea4bc39f6892e5eb16abf6c32a7f",
+  "gen_hash_rust": "sha256:904b4dbf3b398af5e281b09f7a533ffe2bd67e12c646fa80c30f026f906997da",
   "gen_hash_verilog": "sha256:b583ddb95a9f88564a413b72373d1a5f86231c342105564d8b46339a6ebf3fda",
   "gen_hash_zig": "sha256:1c478d385f704ea235578ba0dd1942377648649a02e5430aa1086c3c530a7e8c",
   "module": "igla-race-cordic",
   "ring": 12,
-  "sealed_at": "2026-08-30T21:18:16Z",
+  "sealed_at": "2026-09-06T02:37:19Z",
   "sealed_by": "t27c-bootstrap@0.2.0",
   "spec_hash": "sha256:54b1b8bed209dbc8d3dfc4540fd6a44e8dabe47ae4d264d7f0d30df32a0fa6aa",
   "spec_path": "specs/igla/race/cordic.t27"

bootstrap/src/compiler.rs

@@ -24561,6 +24561,39 @@ impl RustCodegen {
             (t, false)
         };
 
+        // A TUPLE maps element by element. Without this arm `(A, B)` fell through to
+        // the default and was emitted verbatim, so an inner `[]f32` -- which every other
+        // position maps to `Vec<f32>` -- reached rustc as `[]f32`. The rule existed and
+        // did not travel into this position. Measured on the corpus: 6 specs.
+        //
+        // The split is DEPTH-AWARE. A naive `split(',')` would cut `(Map<K, V>, T)` into
+        // `Map<K` and ` V>` and produce something worse than the input.
+        if base_type.starts_with('(') && base_type.ends_with(')') && base_type.len() > 2 {
+            let inner = &base_type[1..base_type.len() - 1];
+            let mut parts: Vec<String> = Vec::new();
+            let (mut depth, mut start) = (0i32, 0usize);
+            for (i, c) in inner.char_indices() {
+                match c {
+                    '<' | '[' | '(' => depth += 1,
+                    '>' | ']' | ')' => depth -= 1,
+                    ',' if depth == 0 => {
+                        parts.push(inner[start..i].to_string());
+                        start = i + c.len_utf8();
+                    }
+                    _ => {}
+                }
+            }
+            parts.push(inner[start..].to_string());
+            // A one-element "tuple" is a parenthesised type, not a tuple, and Rust writes
+            // it without the comma. Emitting `(T,)` there would change the type.
+            let mapped: Vec<String> = parts
+                .iter()
+                .map(|q| Self::t27_type_to_rust(q.trim()))
+                .collect();
+            let joined = format!("({})", mapped.join(", "));
+            return if is_optional { format!("Option<{joined}>") } else { joined };
+        }
+
         let rust_type = match base_type {
             "u8" | "u16" | "u32" | "u64" | "u128" => base_type.to_string(),
             "i8" | "i16" | "i32" | "i64" | "i128" => base_type.to_string(),

bootstrap/stage0/FROZEN_HASH

@@ -1 +1 @@
-ca169bfed429665e761170e0337ed3423cc6649b6a0e1c444faf3f5227bef80e bootstrap/src/compiler.rs
+b109be394c5276ba477b0233a9d344b6d223becff24955ff4dda286b9870716a bootstrap/src/compiler.rs

docs/now/2026-09-06-a-tuple-type-was-emitted-verbatim.md

@@ -0,0 +1,19 @@
+# NOW -- A tuple type was emitted verbatim (2026-09-06)
+
+## A tuple type was emitted verbatim (Refs #3345)
+
+- The Rust type mapper had no arm for a tuple, so `(A, B)` fell through to the default and
+  an inner `[]f32` -- which every other position maps to `Vec<f32>` -- reached rustc
+  as `[]f32`.
+- Measured: 3 specs emitted `-> (...[]...)` before, 0 after. The class is closed.
+- **+0 on the column.** All three still fail on other defects; two of the three changed
+  their failure cause, which is how the fix was confirmed rather than assumed.
+- My first count of the class was 6 and it was wrong. The matcher also caught
+  `std.StringHashMap([]Const u8)` and `std.HashMap(T, []T)` -- Zig standard-library
+  types leaking into the Rust output, not tuples. That is a separate class of 8 specs.
+- The split is depth-aware, because a naive `split(',')` would cut `(Map<K, V>, T)`
+  into `Map<K` and ` V>` and emit something worse than the input. Controls:
+  `([]f32, []u8)` maps both elements; the one-element `(u32)` stays `(u32)` and does
+  not become the one-tuple `(u32,)`, which would be a different type.
+- Found by censusing the FIRST rustc error of all 245 failures together with the generated
+  LINE, which is what separated four classes inside one error text.