feat: plan 08 part B known-case folding, representation cancellation and default O1

.sampo/changesets/integer-inverse-trial.md

@@ -0,0 +1,5 @@
+---
+cargo/nash-ir: minor
+---
+
+Add an isolated integer representation cancellation pass with structural runtime-shape evidence and preserved operand evaluation.

.sampo/changesets/iterative-assembly.md

@@ -0,0 +1,7 @@
+---
+cargo/nash-ir: patch
+cargo/nash-codegen: patch
+cargo/nash-plutus: patch
+---
+
+Replace recursive Core and UPLC assembly traversals with heap work lists. Remove the O1 stack enlargement while preserving traversal order, generated code, traces, and lowering diagnostics.

.sampo/changesets/iterative-core-printing.md

@@ -0,0 +1,5 @@
+---
+cargo/nash-ir: patch
+---
+
+Render deep Core term trees with a heap work list while preserving diagnostic and snapshot formatting.

.sampo/changesets/known-constructor-fields.md

@@ -0,0 +1,5 @@
+---
+cargo/nash-ir: minor
+---
+
+Fold field accesses on known native constructors while preserving strict field evaluation, escaping values, and malformed runtime shapes.

.sampo/changesets/known-literal-cases.md

@@ -0,0 +1,5 @@
+---
+cargo/nash-ir: minor
+---
+
+Fold known native integer and byte case subjects while preserving invalid tables, runtime failures, and strict evaluation.

.sampo/changesets/o1-build-default.md

@@ -0,0 +1,12 @@
+---
+cargo/nash-config: minor
+cargo/nash-codegen: minor
+cargo/nash-driver: minor
+cargo/nash-cli: minor
+cargo/nash-ir: patch
+cargo/nash-plutus: patch
+---
+
+Make trace-preserving O1 optimization the default for builds and tests, with explicit O0/O1 CLI and project settings. Share the accepted optimizer with snapshots and measurements, and include direct integer representation cancellation before ANF.
+
+Print deep UPLC term trees with an explicit work stack.

.sampo/changesets/representation-cancellation.md

@@ -0,0 +1,6 @@
+---
+cargo/nash-ir: patch
+cargo/nash-codegen: patch
+---
+
+Cancel proven integer, byte, list, map and UTF-8 representation round trips, including let-bound operands and constructor Data projections/reconstruction, while preserving validation, traces and evaluation order. Run cancellation in the O1 cleanup loop as well as before normalization.

CLAUDE.md

@@ -69,8 +69,9 @@ pass's layer. All codegen snapshots that generate executable Core group unoptimi
 unoptimized UPLC, followed by optimized Core then optimized UPLC. The unoptimized
 side uses original compiled or hand-built Core and ordinary lowering, with only required
 recursion encoding: no optimization passes or builtin/constant sharing.
-Use the shared test-only accepted pipeline in `crates/nash-codegen/tests/support/optimizer.rs`
-so each accepted optimization updates the whole fixture corpus. Pass tests retain
+Use the shared production O1 pipeline in `crates/nash-codegen/src/optimizer.rs`,
+rendered by `crates/nash-codegen/tests/support/optimizer.rs`, so each accepted
+optimization updates the whole fixture corpus. Pass tests retain
 isolated-pass evidence after that comparison. Diagnostic/metadata snapshots stay
 focused; invalid Core records lowering errors, open Core is closed explicitly for
 pipeline rendering, and deliberate divergence is rendered without evaluation.

SPEC.md

@@ -63,7 +63,7 @@ Implementation plans (Plan 08 is in progress; Plans 09 and 10 are complete):
 - [x] 05 Exhaustiveness (`Nitpick/PatternMatches` port) — [plans/05-nitpick.md](plans/05-nitpick.md)
 - [x] 06 Diagnostics (`nash-report`, concise source labels, stable codes, JSON/LSP) — [plans/06-diagnostics.md](plans/06-diagnostics.md); [concise diagnostics refactor](plans/diagnostics-refactor.md) complete
 - [x] 07 Codegen: Core IR, monomorphization, decision trees, recursion, Data casts, UPLC lowering — [plans/07-codegen.md](plans/07-codegen.md)
-- [ ] 08 Optimizer: Single ANF normalization and optimization before recursion rewrite, inlining, builtin force caching, DCE, case-of-known-ctor/constant folding — [plans/08-optimizer.md](plans/08-optimizer.md) (Chunks 1–3 complete: analysis, hygiene, typed Core, pre-ANF static lifting, ANF and the isolated performance runner; Chunk 4 rules 1–3 accepted)
+- [ ] 08 Optimizer: Single ANF normalization and optimization before recursion rewrite, inlining, builtin force caching, DCE, case-of-known-ctor/constant folding — [plans/08-optimizer.md](plans/08-optimizer.md) (Retained scope of Chunks 1–8 accepted; representation cancellation and O0/O1 build/test/config integration available; recursive unused-parameter removal, Chunks 9–10 and final composition review open)
 - [x] 09 Validators + `nash build` — [plans/09-validators-build.md](plans/09-validators-build.md)
 - [x] 10 Testing: `tests` block, props, generators, shrinking, power-assert, `nash test` — [plans/10-testing.md](plans/10-testing.md)
 - [ ] 11 Macros + comptime — [plans/11-macros-comptime.md](plans/11-macros-comptime.md); includes explicit integer-dispatch AST and positional library macro (chunk 13), reusable call/binding/case-shaped macro inputs required in chunk 14 (library semantics deferred)

crates/nash-cli/src/cli.rs

@@ -46,6 +46,23 @@ mod tests {
     use super::*;
     use clap::CommandFactory;
 
+    #[test]
+    fn optimization_flags() {
+        for command in ["build", "test"] {
+            for flag in ["-O0", "-O1"] {
+                let cli = Cli::try_parse_from(["nash", command, flag]).unwrap();
+                let level = match cli.cmd {
+                    crate::cmd::Cmd::Build(args) => args.optimize,
+                    crate::cmd::Cmd::Test(args) => args.optimize,
+                    _ => unreachable!(),
+                };
+                assert_eq!(u8::from(level.unwrap()), flag.as_bytes()[2] - b'0');
+            }
+            assert!(Cli::try_parse_from(["nash", command, "--optimize", "1"]).is_ok());
+            assert!(Cli::try_parse_from(["nash", command, "-O2"]).is_err());
+        }
+    }
+
     #[test]
     fn command_schema_is_consistent() {
         Cli::command().debug_assert();

crates/nash-cli/src/cmd/build.rs

@@ -5,6 +5,9 @@ use tokio::sync::Mutex;
 
 #[derive(clap::Args)]
 pub struct Args {
+    /// Optimization level: 0 (baseline) or 1 (preserves enabled traces).
+    #[arg(short = 'O', long)]
+    pub optimize: Option<nash_config::OptimizationLevel>,
     /// Path to the project.
     #[arg(default_value = ".")]
     pub path: PathBuf,
@@ -85,6 +88,9 @@ impl Args {
                         PlutusVersionArg::V3 => nash_config::PlutusVersion::V3,
                     };
                 }
+                if let Some(level) = self.optimize {
+                    config.optimize = level;
+                }
                 if let Some(level) = self.trace_level {
                     config.trace_level = match level {
                         TraceLevelArg::Silent => nash_config::TraceLevel::Silent,

crates/nash-cli/src/cmd/test.rs

@@ -14,6 +14,9 @@ pub enum Coverage {
 
 #[derive(clap::Args)]
 pub struct Args {
+    /// Optimization level: 0 (baseline) or 1 (preserves enabled traces).
+    #[arg(short = 'O', long)]
+    pub optimize: Option<nash_config::OptimizationLevel>,
     #[arg(default_value = ".")]
     pub path: PathBuf,
     #[arg(long)]
@@ -105,6 +108,9 @@ impl Args {
                     .filter(|(directory, _)| path.starts_with(directory))
                     .max_by_key(|(directory, _)| directory.components().count())
                     .map_or_else(|| project.config.build().for_tests(), |(_, config)| *config);
+                if let Some(level) = self.optimize {
+                    config.optimize = level;
+                }
                 if let Some(level) = self.trace_level {
                     config.trace_level_explicit = true;
                     config.trace_level = match level {

crates/nash-codegen/src/build/snapshots/nash_codegen__build__tests__aggregate_destructuring_preserves_generalized_components.snap

@@ -1,6 +1,5 @@
 ---
 source: crates/nash-codegen/src/build/tests.rs
-assertion_line: 239
 description: "module Main exposing (..)\nimport Primitive exposing (..)\nimport Builtin exposing (..)\nmain : (unit, bool)\nmain =\n    let\n        (identity, second) = (\\x -> x, \\x -> x)\n    in\n    (identity (), second True)\n"
 ---
 --- unoptimized Core
@@ -45,25 +44,9 @@ main#1
       (lam value_18 value_18)])
     (lam value_17 value_17)])
 --- optimized Core
-let destruct#26 : ('erased -> 'erased, 'erased -> 'erased) = constr 0 (\x#24 : 'erased -> x#24) (\x#25 : 'erased -> x#25) in
-let anf#39 : unit -> unit = case@Tag destruct#26 of
-  0 field#28 field#29 -> field#28 in
-let evaluated#32 : unit = anf#39 () in
-let anf#41 : bool -> bool = case@Tag destruct#26 of
-  0 field#34 field#35 -> field#35 in
-let anf#43 : bool = anf#41 true in
-constr 0 evaluated#32 anf#43
+constr 0 () true
 --- optimized UPLC
-(program 1.1.0
-  [(lam destruct_3
-    [(lam anf_6
-      [(lam evaluated_7
-        [(lam anf_10
-          [(lam anf_11 (constr 0 evaluated_7 anf_11)) [anf_10 (con bool True)]])
-          (case destruct_3 (lam field_8 (lam field_9 field_9)))])
-        [anf_6 (con unit ())]])
-      (case destruct_3 (lam field_4 (lam field_5 field_4)))])
-    (constr 0 (lam x_1 x_1) (lam x_2 x_2))])
+(program 1.1.0 (constr 0 (con unit ()) (con bool True)))
 --- result
 (constr 0 (con unit ()) (con bool True))
 --- logs

crates/nash-codegen/src/build/snapshots/nash_codegen__build__tests__higher_kinded_default_method_accepts_a_nominal_record_alias.snap

@@ -1,6 +1,5 @@
 ---
 source: crates/nash-codegen/src/build/tests.rs
-assertion_line: 239
 description: "module Main exposing (..)\nimport Primitive exposing (..)\nimport Builtin exposing (..)\ntype alias box 'a = { value : 'a }\ntrait Pass 'f where\n    pass : 'f 'a -> 'f 'a\n    pass x = x\n    other : 'f 'a -> 'f 'a\nimpl Pass box where\n    other x = x\nboxed : box unit\nboxed = { value = () }\nmain = (pass boxed).value\n"
 ---
 --- unoptimized Core
@@ -24,12 +23,9 @@ main#1
       (lam value_6 value_6)])
     (lam x_4 x_4)])
 --- optimized Core
-let boxed#13 : { _0 : unit } = constr 0 () in
-field@0/1 boxed#13
+()
 --- optimized UPLC
-(program 1.1.0
-  [(lam boxed_1 (case boxed_1 (lam generated_2 generated_2)))
-    (constr 0 (con unit ()))])
+(program 1.1.0 (con unit ()))
 --- result
 (con unit ())
 --- logs

crates/nash-codegen/src/build/snapshots/nash_codegen__build__tests__little_constructor_record_accesses_each_field.snap

@@ -1,6 +1,5 @@
 ---
 source: crates/nash-codegen/src/build/tests.rs
-assertion_line: 1450
 description: "module Main exposing (..)\nimport Primitive exposing (..)\nimport Builtin exposing (..)\ntype entry = Entry { count : int, enabled : bool, label : bytes }\nmain =\n    let\n        item = Entry { label = #\"aabb\", enabled = True, count = 42 }\n    in\n    if item.enabled then addInteger item.count (lengthOfByteString item.label) else 0\n"
 ---
 --- unoptimized Core
@@ -47,33 +46,12 @@ main#1
       (lam value_10 value_10)])
     (lam value_9 value_9)])
 --- optimized Core
-let item#24 : Main.entry = constr 0 42 true (con bytestring #aabb) in
-let projection#25 : bool = field@1/3 item#24 in
-case@Bool projection#25 of
-  True -> let projection#26 : int = field@0/3 item#24 in
-  let projection#27 : bytes = field@2/3 item#24 in
-  let anf#34 : int = lengthOfByteString projection#27 in
-  addInteger projection#26 anf#34
-  False -> 0
+let anf#34 : int = lengthOfByteString (con bytestring #aabb) in
+addInteger 42 anf#34
 --- optimized UPLC
 (program 1.1.0
-  [(lam item_1
-    [(lam projection_2
-      (case
-        projection_2
-        (con integer 0)
-        [(lam projection_3
-          [(lam projection_4
-            [(lam anf_5 [[(builtin addInteger) projection_3] anf_5])
-              [(builtin lengthOfByteString) projection_4]])
-            (case item_1 (lam generated_6 (lam generated_7 (lam generated_8 generated_8))))])
-          (case
-            item_1
-            (lam generated_9 (lam generated_10 (lam generated_11 generated_9))))]))
-      (case
-        item_1
-        (lam generated_12 (lam generated_13 (lam generated_14 generated_13))))])
-    (constr 0 (con integer 42) (con bool True) (con bytestring #aabb))])
+  [(lam anf_1 [[(builtin addInteger) (con integer 42)] anf_1])
+    [(builtin lengthOfByteString) (con bytestring #aabb)]])
 --- result
 (con integer 44)
 --- logs

crates/nash-codegen/src/build/snapshots/nash_codegen__build__tests__primitive_map_unwrap_retains_structural_eq.snap

@@ -1,6 +1,5 @@
 ---
 source: crates/nash-codegen/src/build/tests.rs
-assertion_line: 239
 description: "module Main exposing (..)\nimport Primitive exposing (..)\nimport Builtin exposing (..)\nimport Literal exposing (..)\nimport Eq exposing (..)\nencoded : Map Int Int\nencoded = Builtin.mapData [Builtin.mkPairData 1 2]\nnative = Builtin.unMapData encoded\nmain = eq native native\n"
 ---
 --- unoptimized Core
@@ -33,25 +32,20 @@ let anf#19 : pair Int Int = mkPairData anf#17 anf#18 in
 let anf#20 : list (pair Int Int) = mkCons anf#19 (con (list (pair data data)) []) in
 let encoded#12 : Map Int Int = mapData anf#20 in
 let native#13 : list (pair Int Int) = unMapData encoded#12 in
-let anf#15 : Map 'erased 'erased = mapData native#13 in
-let anf#16 : Map 'erased 'erased = mapData native#13 in
-equalsData anf#15 anf#16
+equalsData encoded#12 encoded#12
 --- optimized UPLC
 (program 1.1.0
-  [(lam builtin_10
+  [(lam builtin_8
     [(lam fromInt_1
       [(lam anf_2
         [(lam anf_3
           [(lam anf_4
             [(lam anf_5
               [(lam encoded_6
-                [(lam native_7
-                  [(lam anf_8
-                    [(lam anf_9 [[(builtin equalsData) anf_8] anf_9]) [(builtin mapData) native_7]])
-                    [(builtin mapData) native_7]])
+                [(lam native_7 [[(builtin equalsData) encoded_6] encoded_6])
                   [(builtin unMapData) encoded_6]])
                 [(builtin mapData) anf_5]])
-              [[builtin_10 anf_4] (con (list (pair data data)) [])]])
+              [[builtin_8 anf_4] (con (list (pair data data)) [])]])
             [[(builtin mkPairData) anf_2] anf_3]])
           [fromInt_1 (con integer 2)]])
         [fromInt_1 (con integer 1)]])

crates/nash-codegen/src/build/snapshots/nash_codegen__build__tests__record_wire_order_access_update_and_accessor_execute.snap

@@ -1,6 +1,5 @@
 ---
 source: crates/nash-codegen/src/build/tests.rs
-assertion_line: 239
 description: "module Main exposing (..)\nimport Primitive exposing (..)\nimport Builtin exposing (..)\ntype alias person = { age : int, active : bool }\nread : person -> int\nread = .age\noriginal : person\noriginal = { active = True, age = 1 }\nmain : int\nmain = read { original | age = 42 }\n"
 ---
 --- unoptimized Core
@@ -34,18 +33,9 @@ main#1
       [(lam projection_10 projection_10)
         (case record_6 (lam generated_15 (lam generated_16 generated_15)))])])
 --- optimized Core
-let original#20 : { _0 : int, _1 : bool } = constr 0 1 true in
-let projection#23 : bool = field@1/2 original#20 in
-let anf#27 : { _0 : int, _1 : bool } = constr 0 42 projection#23 in
-field@0/2 anf#27
+42
 --- optimized UPLC
-(program 1.1.0
-  [(lam original_1
-    [(lam projection_2
-      [(lam anf_3 (case anf_3 (lam generated_4 (lam generated_5 generated_4))))
-        (constr 0 (con integer 42) projection_2)])
-      (case original_1 (lam generated_6 (lam generated_7 generated_7)))])
-    (constr 0 (con integer 1) (con bool True))])
+(program 1.1.0 (con integer 42))
 --- result
 (con integer 42)
 --- logs

crates/nash-codegen/src/build/snapshots/nash_codegen__build__tests__source_little_constructor_patterns_and_tuples.snap

@@ -1,6 +1,5 @@
 ---
 source: crates/nash-codegen/src/build/tests.rs
-assertion_line: 239
 description: "module Main exposing (..)\nimport Primitive exposing (..)\nimport Builtin exposing (..)\ntype option 'a = None | Some 'a\nunwrap fallback opt =\n    case opt of\n        None -> fallback\n        Some x -> x\nmain : unit\nmain = unwrap () (Some ())\n"
 ---
 --- unoptimized Core
@@ -25,14 +24,9 @@ main#1
         [(lam match_8 (case match_8 fallback_5 (lam field_9 [(lam x_7 x_7) field_9])))
           opt_6]))])
 --- optimized Core
-let anf#24 : Main.option unit = constr 1 () in
-case@Tag anf#24 of
-  0 -> ()
-  1 field#14 -> field#14
+()
 --- optimized UPLC
-(program 1.1.0
-  [(lam anf_1 (case anf_1 (con unit ()) (lam field_2 field_2)))
-    (constr 1 (con unit ()))])
+(program 1.1.0 (con unit ()))
 --- result
 (con unit ())
 --- logs

crates/nash-codegen/src/build/snapshots/nash_codegen__build__tests__source_shared_default_leaf.snap

@@ -1,6 +1,5 @@
 ---
 source: crates/nash-codegen/src/build/tests.rs
-assertion_line: 1281
 description: "module Main exposing (..)\nimport Primitive exposing (..)\nimport Builtin exposing (..)\nmain : bool\nmain =\n    case (False, False) of\n        (True, True) -> True\n        _ -> trace \"default\" False\n"
 ---
 --- unoptimized Core
@@ -41,26 +40,11 @@ main#1
       (lam value_10 value_10)])
     (con string "default")])
 --- optimized Core
-let match#16 : (bool, bool) = constr 0 false false in
-let leaf#17 : @delay bool = delay (trace "default" in false) in
-case@Tag match#16 of
-  0 field#18 field#19 -> case@Bool field#18 of
-    False -> force leaf#17
-    True -> case@Bool field#19 of
-      False -> force leaf#17
-      True -> true
+trace "default" in false
 --- optimized UPLC
 (program 1.1.0
-  [(lam builtin_5
-    [(lam match_1
-      [(lam leaf_2
-        (case
-          match_1
-          (lam field_3
-            (lam field_4
-              (case field_3 (force leaf_2) (case field_4 (force leaf_2) (con bool True)))))))
-        (delay (force [[builtin_5 (con string "default")] (delay (con bool False))]))])
-      (constr 0 (con bool False) (con bool False))])
+  [(lam builtin_1
+    (force [[builtin_1 (con string "default")] (delay (con bool False))]))
     (force (builtin trace))])
 --- result
 (con bool False)