[codex] r3 gate 50 one-shot memoization witness

src/v3/compiler/src/test_runner.rs

@@ -54,6 +54,13 @@ const R3_PARALLEL_EMIT_WITNESS_LENS_NAME: &str = "r3_auto_parallelism_parallel_e
 const R3_BRANCH_ARMS_SERIALIZE_WITNESS_LENS_NAME: &str =
     "r3_auto_parallelism_branch_arms_serialize_witness";
 
+/// R3 gate #50 (`LensOutputEquals` witness in `r3_free_consequences_first_batch.dag`).
+///
+/// A one-shot pure call may emit a direct call / inlined expression, but must not introduce
+/// memoization scaffolding. Repeated-call caching remains deferred to the purity+cost lens
+/// composition producer.
+const R3_ONE_SHOT_NO_MEMO_WITNESS_LENS_NAME: &str = "r3_auto_memoization_one_shot_no_cache_witness";
+
 /// Host-written forward fold for structural depth costs (see `src/v3/lenses/complexity.dag`).
 ///
 /// T-LaneE `DifferentialEquals` compares this receipt to [`crate::lens_cost::cost_of`] (emit output
@@ -2387,6 +2394,50 @@ impl<'a> TestRunner<'a> {
             };
         }
 
+        // R3 gate #50 (`auto_memoization_no_caching_for_one_shot`): one-shot call sites must not
+        // emit memo/cache scaffolding. Structural witness via emitted Rust text; dissolution when
+        // the AutoMemoizationEvidence producer reaches `.dag`.
+        if lens_decl.name.as_deref() == Some(R3_ONE_SHOT_NO_MEMO_WITNESS_LENS_NAME) {
+            let expected_int = match expected_decl.value_body.as_ref() {
+                Some(ValueBody::Scalar(LiteralBits::Int(s))) => match s.parse::<i64>() {
+                    Ok(v) => v,
+                    Err(_) => {
+                        return ClaimResult::Fail(format!(
+                            "LensOutputEquals(r3_auto_memoization_one_shot_no_cache_witness): expected Int literal is not a valid i64 decimal for `{expected_name}`"
+                        ));
+                    }
+                },
+                _ => {
+                    return ClaimResult::Fail(format!(
+                        "LensOutputEquals(r3_auto_memoization_one_shot_no_cache_witness): expected_ref `{expected_name}` must be `data ...: Int = <literal>`"
+                    ));
+                }
+            };
+            let emitted = match crate::emit_rust::emit_rust(&program_dag) {
+                Ok(s) => s,
+                Err(err) => {
+                    return ClaimResult::Fail(format!(
+                        "LensOutputEquals(r3_auto_memoization_one_shot_no_cache_witness): emit_rust failed for `{}`: {err:?}",
+                        claim.file_name
+                    ));
+                }
+            };
+            let scaffolding_absent = !emitted.contains("memo")
+                && !emitted.contains("Memo")
+                && !emitted.contains("cache")
+                && !emitted.contains("Cache")
+                && !emitted.contains("HashMap");
+            let computed_int = i64::from(scaffolding_absent);
+            return if computed_int == expected_int {
+                ClaimResult::Pass
+            } else {
+                ClaimResult::Fail(format!(
+                    "LensOutputEquals(r3_auto_memoization_one_shot_no_cache_witness): expected `{expected_int}` (1 = no memo/cache scaffolding), computed `{computed_int}` for `{}`",
+                    claim.file_name
+                ))
+            };
+        }
+
         // T-LaneE cost receipt: `ProgramOutputBind` is the structural contract for a claim
         // source output-bind cost check. Dispatch on that input role, not on lens declaration
         // spelling; otherwise the canonical lens-name bridge would survive under a helper.

src/v3/compiler/tests/fixtures/r3_free_consequences_first_batch.dag

@@ -54,6 +54,11 @@ fn r3_auto_parallelism_branch_arms_serialize_witness(_d: Dag) -> Int = 0
 
 data r3_auto_parallelism_branch_arms_serialize_expected: Int = 1
 
+// R3 #50 witness: one-shot pure call sites must not emit memo/cache scaffolding.
+fn r3_auto_memoization_one_shot_no_cache_witness(_d: Dag) -> Int = 0
+
+data r3_auto_memoization_one_shot_no_cache_expected: Int = 1
+
 type repeated_pure_call_observed_report = DimensionReport<AutoMemoizationEvidence>
 type repeated_pure_call_expected_report = DimensionReport<AutoMemoizationEvidence>
 type one_shot_call_observed_report = DimensionReport<AutoMemoizationEvidence>
@@ -108,11 +113,12 @@ data auto_memoization_repeated_pure_call_cached: TestClaim = {
 
 data auto_memoization_no_caching_for_one_shot: TestClaim = {
   name: "auto_memoization_no_caching_for_one_shot",
-  source: "// free-consequences fixture: one-shot calls do not emit memoization scaffolding.\nlet _: Int = 0\n",
+  source: "// free-consequences fixture: one-shot calls do not emit memoization scaffolding.\nfn bump(x: Int) -> Int = x + 1\nlet _: Int = bump(41)\n",
   file_name: "r3_free_consequences_auto_memoization_one_shot.v3",
-  predicate: BinaryDimensionReportEquals(
-    one_shot_call_observed_report,
-    one_shot_call_expected_report
+  predicate: LensOutputEquals(
+    r3_auto_memoization_one_shot_no_cache_witness,
+    auto_parallelism_program_input,
+    r3_auto_memoization_one_shot_no_cache_expected
   ),
   requires: []
 }

src/v3/compiler/tests/integration/r3_free_consequences_first_batch_test.rs

@@ -2,11 +2,10 @@
 //!
 //! R3 T-Free-Consequences first-batch author-now/fire-later claims.
 //! Gate `#43` asserts pairwise-independent top-level binds emit a parallel Rust
-//! schedule, and gate `#45` asserts a Bool branch lowers to `if … else` with no
-//! `thread::scope` scheduling on the arms (both `LensOutputEquals` + runner
-//! witnesses). Gate `#44` stays fail-closed on the scalar parallelism
-//! placeholder; auto-memoization claims lock the `BinaryDimensionReportEquals`
-//! shape.
+//! schedule; gate `#44` stays fail-closed on the scalar parallelism placeholder;
+//! gate `#45` asserts a Bool branch lowers to `if … else` with no `thread::scope`
+//! scheduling on the arms; gate `#50` asserts one-shot pure calls do not emit
+//! memo/cache scaffolding. Repeated-call memoization remains deferred.
 
 use v3_compiler::compile_to_dag;
 use v3_compiler::test_runner::{ClaimResult, TestRunner};
@@ -76,8 +75,7 @@ fn r3_free_consequences_first_batch_reaches_unified_predicate_shape_inner() {
                     result.result
                 );
             }
-            "auto_memoization_repeated_pure_call_cached"
-            | "auto_memoization_no_caching_for_one_shot" => {
+            "auto_memoization_repeated_pure_call_cached" => {
                 assert!(
                     matches!(
                         &result.result,
@@ -89,6 +87,13 @@ fn r3_free_consequences_first_batch_reaches_unified_predicate_shape_inner() {
                     result.result
                 );
             }
+            "auto_memoization_no_caching_for_one_shot" => {
+                assert!(
+                    matches!(&result.result, ClaimResult::Pass),
+                    "expected {expected_name} to Pass (one-shot memoization absence witness), got {:?}",
+                    result.result
+                );
+            }
             _ => panic!("unexpected claim name: {expected_name}"),
         }
     }