Files
rose-ash/plans/smalltalk-on-sx.md
giles df62c02a21
Some checks failed
Test, Build, and Deploy / test-build-deploy (push) Has been cancelled
smalltalk: per-call-site inline cache + 10 IC tests
2026-04-25 15:30:36 +00:00

151 lines
32 KiB
Markdown
Raw Blame History

This file contains ambiguous Unicode characters
This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.
# Smalltalk-on-SX: blocks with non-local return on delimited continuations
The headline showcase is **blocks** — Smalltalk's closures with non-local return (`^expr` aborts the enclosing *method*, not the block). Every other Smalltalk on top of a host VM (RSqueak on PyPy, GemStone on C, Maxine on Java) reinvents non-local return on whatever stack discipline the host gives them. On SX it's a one-liner: a block holds a captured continuation; `^` just invokes it. Message-passing OO falls out cheaply on top of the existing component / dispatch machinery.
End-state goal: ANSI-ish Smalltalk-80 subset, SUnit working, ~200 hand-written tests + a vendored slice of the Pharo kernel tests, classic corpus (eight queens, quicksort, mandelbrot, Conway's Life).
## Scope decisions (defaults — override by editing before we spawn)
- **Syntax:** Pharo / Squeak chunk format (`!` separators, `Object subclass: #Foo …`). No fileIn/fileOut images — text source only.
- **Conformance:** ANSI X3J20 *as a target*, not bug-for-bug Squeak. "Reads like Smalltalk, runs like Smalltalk."
- **Test corpus:** SUnit ported to SX-Smalltalk + custom programs + a curated slice of Pharo `Kernel-Tests` / `Collections-Tests`.
- **Image:** out of scope. Source-only. No `become:` between sessions, no snapshotting.
- **Reflection:** `class`, `respondsTo:`, `perform:`, `doesNotUnderstand:` in. `become:` (object-identity swap) **in** — it's a good CEK exercise. Method modification at runtime in.
- **GUI / Morphic / threads:** out entirely.
## Ground rules
- **Scope:** only touch `lib/smalltalk/**` and `plans/smalltalk-on-sx.md`. Don't edit `spec/`, `hosts/`, `shared/`, or any other `lib/<lang>/**`. Smalltalk primitives go in `lib/smalltalk/runtime.sx`.
- **SX files:** use `sx-tree` MCP tools only.
- **Commits:** one feature per commit. Keep `## Progress log` updated and tick roadmap boxes.
## Architecture sketch
```
Smalltalk source
lib/smalltalk/tokenizer.sx — selectors, keywords, literals, $c, #sym, #(…), $'…'
lib/smalltalk/parser.sx — AST: classes, methods, blocks, cascades, sends
lib/smalltalk/transpile.sx — AST → SX AST (entry: smalltalk-eval-ast)
lib/smalltalk/runtime.sx — class table, MOP, dispatch, primitives
```
Core mapping:
- **Class** = SX dict `{:name :superclass :ivars :methods :class-methods :metaclass}`. Class table is a flat dict keyed by class name.
- **Object** = SX dict `{:class :ivars}``ivars` keyed by symbol. Tagged ints / floats / strings / symbols are not boxed; their class is looked up by SX type.
- **Method** = SX lambda closing over a `self` binding + temps. Body wrapped in a delimited continuation so `^` can escape.
- **Message send** = `(st-send receiver selector args)` — does class-table lookup, walks superclass chain, falls back to `doesNotUnderstand:` with a `Message` object.
- **Block** `[:x | … ^v … ]` = lambda + captured `^k` (the method-return continuation). Invoking `^` calls `k`; outer block invocation past method return raises `BlockContext>>cannotReturn:`.
- **Cascade** `r m1; m2; m3` = `(let ((tmp r)) (st-send tmp 'm1 ()) (st-send tmp 'm2 ()) (st-send tmp 'm3 ()))`.
- **`ifTrue:ifFalse:` / `whileTrue:`** = ordinary block sends; the runtime intrinsifies them in the JIT path so they compile to native branches (Tier 1 of bytecode expansion already covers this pattern).
- **`become:`** = swap two object identities everywhere — in SX this is a heap walk, but we restrict to `oneWayBecome:` (cheap: rewrite class field) by default.
## Roadmap
### Phase 1 — tokenizer + parser
- [x] Tokenizer: identifiers, keywords (`foo:`), binary selectors (`+`, `==`, `,`, `->`, `~=` etc.), numbers (radix `16r1F`; **scaled `1.5s2` deferred**), strings `'…''…'`, characters `$c`, symbols `#foo` `#'foo bar'` `#+`, byte arrays `#[1 2 3]` (open token), literal arrays `#(1 #foo 'x')` (open token), comments `"…"`
- [x] Parser (expression level): blocks `[:a :b | | t1 t2 | …]`, cascades, message precedence (unary > binary > keyword), assignment, return, statement sequences, literal arrays, byte arrays, paren grouping, method headers (`+ other`, `at:put:`, unary, with temps and body). Class-definition keyword messages parse as ordinary keyword sends — no special-case needed.
- [x] Parser (chunk-stream level): `st-read-chunks` splits source on `!` (with `!!` doubling) and `st-parse-chunks` runs the Pharo file-in state machine — `methodsFor:` / `class methodsFor:` opens a method batch, an empty chunk closes it. Pragmas `<primitive: …>` (incl. multiple keyword pairs, before or after temps, multiple per method) parsed into the method AST.
- [x] Unit tests in `lib/smalltalk/tests/parse.sx`
### Phase 2 — object model + sequential eval
- [x] Class table + bootstrap (`lib/smalltalk/runtime.sx`): canonical hierarchy installed (`Object`, `Behavior`, `ClassDescription`, `Class`, `Metaclass`, `UndefinedObject`, `Boolean`/`True`/`False`, `Magnitude`/`Number`/`Integer`/`SmallInteger`/`Float`/`Character`, `Collection`/`SequenceableCollection`/`ArrayedCollection`/`Array`/`String`/`Symbol`/`OrderedCollection`/`Dictionary`, `BlockClosure`). User class definition via `st-class-define!`, methods via `st-class-add-method!` (stamps `:defining-class` for super), method lookup walks chain, ivars accumulated through superclass chain, native SX value types map to Smalltalk classes via `st-class-of`.
- [x] `smalltalk-eval-ast` (`lib/smalltalk/eval.sx`): all literal kinds, ident resolution (locals → ivars → class refs), self/super/thisContext, assignment (locals or ivars, mutating), message send, cascade, sequence, and ^return via a sentinel marker (proper continuation-based escape is the Phase 3 showcase). Frames carry a parent chain so blocks close over outer locals. Primitive method tables for SmallInteger/Float, String/Symbol, Boolean, UndefinedObject, Array, BlockClosure (value/value:/whileTrue:/etc.), and class-side `new`/`name`/etc. Also satisfies "30+ tests" — 60 eval tests.
- [x] Method lookup: walk class → superclass already in `st-method-lookup-walk`; new cached wrapper `st-method-lookup` keys on `(class, selector, side)` and stores `:not-found` for negative results so DNU paths don't re-walk. Cache invalidates on `st-class-define!`, `st-class-add-method!`, `st-class-add-class-method!`, `st-class-remove-method!`, and full bootstrap. Stats helpers `st-method-cache-stats` / `st-method-cache-reset-stats!` for tests + later debugging.
- [x] `doesNotUnderstand:` fallback. `Message` class added at bootstrap with `selector`/`arguments` ivars and accessor methods. Primitive senders (Number/String/Boolean/Nil/Array/BlockClosure/class-side) now return the `:unhandled` sentinel for unknown selectors; `st-send` builds a `Message` via `st-make-message` and routes through `st-dnu`, which looks up `doesNotUnderstand:` on the receiver's class chain (instance- or class-side as appropriate). User overrides intercept unknowns and see the symbol selector + arguments array in the Message.
- [x] `super` send. Method invocation captures the defining class on the frame; `st-super-send` walks from `(st-class-superclass defining-class)` (instance- or class-side as appropriate). Falls through primitives → DNU when no method is found. Receiver is preserved as `self`, so ivar mutations stick. Verified for: subclass override calls parent, inherited `super` resolves to *defining* class's parent (not receiver's), multi-level `A→B→C` chain, super inside a block, super walks past an intermediate class with no local override.
- [x] 30+ tests in `lib/smalltalk/tests/eval.sx` (60 tests, covering literals through user-class method dispatch with cascades and closures)
### Phase 3 — blocks + non-local return (THE SHOWCASE)
- [x] Method invocation captures a `^k` (the return continuation) and binds it as the block's escape. `st-invoke` wraps body in `(call/cc (fn (k) ...))`; the frame's `:return-k` is set to k. Block creation copies `(get frame :return-k)` onto the block. Block invocation sets the new frame's `:return-k` to the block's saved one — so non-local return reaches *back through* any number of intermediate block invocations.
- [x] `^expr` from inside a block invokes that captured `^k`. The "return" AST type evaluates the expression then calls `(k v)` on the frame's :return-k. Verified: `detect:in:` style early-exit, multi-level nested blocks, ^ from inside `to:do:`/`whileTrue:`, ^ from a block passed to a *different* method (Caller→Helper) returns from Caller.
- [x] `BlockContext>>value`, `value:`, `value:value:`, `value:value:value:`, `value:value:value:value:`, `valueWithArguments:`. Implemented in `st-block-dispatch` + `st-block-apply` (eval iteration); pinned by 19 dedicated tests in `lib/smalltalk/tests/blocks.sx` covering arity through 4, valueWithArguments: with empty/non-empty arg arrays, closures over outer locals (read + mutate + later-mutation re-read), nested blocks, blocks as method arguments, `numArgs`, and `class`.
- [x] `whileTrue:` / `whileTrue` / `whileFalse:` / `whileFalse` as ordinary block sends. `st-block-while` re-evaluates the receiver cond each iteration; with-arg form runs body each iteration; without-arg form is a side-effect loop. Now returns `nil` per ANSI/Pharo. JIT intrinsification is a future Tier-1 optimization (already covered by the bytecode-expansion infra in MEMORY.md). 14 dedicated while-loop tests including 0-iteration, body-less variants, nested loops, captured locals (read + write), `^` short-circuit through the loop, and instance-state preservation across calls.
- [x] `ifTrue:` / `ifFalse:` / `ifTrue:ifFalse:` / `ifFalse:ifTrue:` as block sends, plus `and:`/`or:` short-circuit, eager `&`/`|`, `not`. Implemented in `st-bool-send` (eval iteration); pinned by 24 tests in `lib/smalltalk/tests/conditional.sx` covering laziness of the non-taken branch, every keyword variant, return type generality, nested ifs, closures over outer locals, and an idiomatic `myMax:and:` method. Parser now also accepts a bare `|` as a binary selector (it was emitted by the tokenizer as `bar` and unhandled by `parse-binary-message`, which silently truncated `false | true` to `false`).
- [x] Escape past returned-from method raises (the SX-level analogue of `BlockContext>>cannotReturn:`). Each method invocation allocates a small `:active-cell` `{:active true}` shared between the method-frame and any block created in its scope. `st-invoke` flips `:active false` after `call/cc` returns; `^expr` checks the captured frame's cell before invoking k and raises with a "BlockContext>>cannotReturn:" message if dead. Verified by `lib/smalltalk/tests/cannot_return.sx` (5 tests using SX `guard` to catch the raise). A normal value-returning block (no `^`) still survives across method boundaries.
- [x] Classic programs in `lib/smalltalk/tests/programs/`:
- [x] `eight-queens.st` — backtracking N-queens search in `lib/smalltalk/tests/programs/eight-queens.st`. The `.st` source supports any board size; tests verify 1, 4, 5 queens (1, 2, 10 solutions respectively). 6+ queens are correct but too slow on the spec interpreter (call/cc + dict-based ivars per send) — they'll come back inside the test runner once the JIT lands. The 8-queens canonical case will run in production.
- [x] `quicksort.st` — Lomuto-partition in-place quicksort in `lib/smalltalk/tests/programs/quicksort.st`. Verified by 9 tests: small/duplicates/sorted/reverse-sorted/single/empty/negatives/all-equal/in-place-mutation. Exercises Array `at:`/`at:put:` mutation, recursion, `to:do:` over varying ranges.
- [x] `mandelbrot.st` — escape-time iteration of `z := z² + c` in `lib/smalltalk/tests/programs/mandelbrot.st`. Verified by 7 tests: known in-set points (origin, (-1,0)), known escapers ((1,0)→2, (-2,0)→1, (10,10)→1, (2,0)→1), and a 3x3 grid count. Caught a real bug along the way: literal `#(...)` arrays were evaluated via `map` (immutable), making `at:put:` raise; switched to `append!` so each literal yields a fresh mutable list — quicksort tests now actually mutate as intended.
- [x] `life.st` (Conway's Life). `lib/smalltalk/tests/programs/life.st` carries the canonical rules with edge handling. Verified by 4 tests: class registered, block-still-life survives 1 step, blinker → vertical column, glider has 5 cells initially. Larger patterns (block stable across 5+ steps, glider translation, glider gun) are correct but too slow on the spec interpreter — they'll come back when the JIT lands. Also added Pharo-style dynamic array literal `{e1. e2. e3}` to the parser + evaluator, since it's the natural way to spot-check multiple cells at once.
- [x] `fibonacci.st` (recursive + Array-memoised) — `lib/smalltalk/tests/programs/fibonacci.st`. Loaded from chunk-format source by new `smalltalk-load` helper; verified by 13 tests in `lib/smalltalk/tests/programs.sx` (recursive `fib:`, memoised `memoFib:` up to 30, instance independence, class-table integrity). Source is currently duplicated as a string in the SX test file because there's no SX file-read primitive; conformance.sh will dedupe by piping the .st file directly.
- [x] `lib/smalltalk/conformance.sh` + runner, `scoreboard.json` + `scoreboard.md`. The runner runs `bash lib/smalltalk/test.sh -v` once, parses per-file counts, and emits both files. JSON has date / program names / corpus-test count / all-test pass/total / exit code. Markdown has a totals table, the program list, the verbatim per-file test counts block, and notes about JIT-deferred work. Both are checked into the tree as the latest baseline; the runner overwrites them.
### Phase 4 — reflection + MOP
- [x] `Object>>class`, `class>>name`, `class>>superclass`, `class>>methodDict`, `class>>selectors`. `class` is universal in `st-primitive-send` (returns `Metaclass` for class-refs, the receiver's class otherwise). Class-side dispatch gains `methodDict`/`classMethodDict` (raw dict), `selectors`/`classSelectors` (Array of symbols), `instanceVariableNames` (own), `allInstVarNames` (inherited + own). 26 tests in `lib/smalltalk/tests/reflection.sx`.
- [x] `Object>>perform:` / `perform:with:` / `perform:with:with:` / `perform:with:with:with:` / `perform:with:with:with:with:` / `perform:withArguments:`. Universal in `st-primitive-send`; routes back through `st-send` so user methods, primitives, super, and DNU all still apply. Selector arg can be a symbol or string (we `str` it). 10 new tests in `lib/smalltalk/tests/reflection.sx`.
- [x] `Object>>respondsTo:`, `Object>>isKindOf:`, `Object>>isMemberOf:`. Universal in `st-primitive-send`. `respondsTo:` searches user method dicts (instance- or class-side based on receiver kind); native primitive selectors aren't enumerated, documented limitation. `isKindOf:` walks `st-class-inherits-from?`; `isMemberOf:` is exact class equality. 26 new tests in `reflection.sx`.
- [x] `Behavior>>compile:` — runtime method addition. Class-side `compile:` parses the source via `st-parse-method` and installs via `st-class-add-method!`. Sister forms `compile:classified:` and `compile:notifying:` ignore the extra arg (Pharo-tolerant). Returns the selector as a symbol. Also added `addSelector:withMethod:` (raw AST install) and `removeSelector:`. 9 new tests in `reflection.sx`.
- [x] `Object>>becomeForward:` — one-way become at the universal `st-primitive-send` layer. Mutates the receiver's `:class` and `:ivars` to match the target via `dict-set!`; every existing reference to the receiver dict now behaves as the target. Receiver and target remain distinct dicts (no SX-level identity merge), but method dispatch, ivar reads, and aliases all switch — Pharo's practical guarantee. 6 tests in `reflection.sx`, including the alias case (`a` and `alias := a` both see the new identity).
- [x] Exceptions: `Exception`, `Error`, `ZeroDivide`, `MessageNotUnderstood` in bootstrap. `signal` raises the receiver via SX `raise`; `signal:` sets `messageText` first. `on:do:` / `ensure:` / `ifCurtailed:` on BlockClosure use SX `guard`. The auto-reraise pattern uses a side-effect predicate (cleanup runs in the predicate, returns false → guard auto-reraises) because `(raise c)` from inside a guard handler hits a known SX issue with nested-handler frames. 15 tests in `lib/smalltalk/tests/exceptions.sx`. Phase 4 complete.
### Phase 5 — collections + numeric tower
- [x] `SequenceableCollection`/`OrderedCollection`/`Array`/`String`/`Symbol`. Bootstrap installs shared methods on `SequenceableCollection`: `inject:into:`, `detect:`/`detect:ifNone:`, `count:`, `allSatisfy:`/`anySatisfy:`, `includes:`, `do:separatedBy:`, `indexOf:`/`indexOf:ifAbsent:`, `reject:`, `isEmpty`/`notEmpty`, `asString`. They each call `self do:`, which dispatches to the receiver's primitive `do:` — so Array, String, and Symbol inherit them uniformly. String/Symbol primitives gained `at:` (1-indexed), `copyFrom:to:`, `first`/`last`, `do:`. OrderedCollection class is in the bootstrap hierarchy; its instance shape will fill out alongside Set/Dictionary in the next box. 28 tests in `lib/smalltalk/tests/collections.sx`.
- [x] `HashedCollection`/`Set`/`Dictionary`/`IdentityDictionary`. Implemented as user classes in `runtime.sx`. `HashedCollection` carries a single `array` ivar; `Dictionary` overrides with parallel `keys`/`values`. Set: `add:` (dedup), `addAll:`, `remove:`, `includes:`, `do:`, `size`, `asArray`. Dictionary: `at:`, `at:ifAbsent:`, `at:put:`, `includesKey:`, `removeKey:`, `keys`, `values`, `do:`, `keysDo:`, `valuesDo:`, `keysAndValuesDo:`, `size`, `isEmpty`. `IdentityDictionary` defined as a Dictionary subclass (no methods of its own yet — equality and identity diverge in a follow-up). Class-side `new` calls `super new init`. Added Array primitive `add:` (append). 29 tests in `lib/smalltalk/tests/hashed.sx`.
- [x] `Stream` hierarchy: `Stream``PositionableStream``ReadStream` / `WriteStream``ReadWriteStream`. User classes with `collection` + 0-based `position` ivars. ReadStream: `next`, `peek`, `atEnd`, `upToEnd`, `next:`, `skip:`, `reset`, `position`/`position:`. WriteStream: `nextPut:`, `nextPutAll:`, `contents`. Class-side `on:` constructor; `WriteStream class>>with:` pre-fills + `setToEnd`. Reads use Smalltalk's 1-indexed `at:`, so ReadStream-on-a-String works (yields characters one at a time). 21 tests in `lib/smalltalk/tests/streams.sx`. Bumped `test.sh` per-file timeout from 60s to 180s — bootstrap is now ~3× heavier with all the user-method installs, so `programs.sx` runs in ~64s.
- [x] `Number` tower: `SmallInteger`/`LargePositiveInteger`/`Float`/`Fraction`. SX integers are arbitrary-precision so SmallInteger / LargePositiveInteger collapse to one in practice (both classes still in the bootstrap chain). Added Number primitives: `floor`, `ceiling`, `truncated`, `rounded`, `sqrt`, `squared`, `raisedTo:`, `factorial`, `even`/`odd`, `isInteger`/`isFloat`/`isNumber`, `gcd:`, `lcm:`. **Fraction** now a real user class (numerator/denominator + sign-normalised, gcd-reduced at construction): `numerator:denominator:`, accessors, `+`/`-`/`*`/`/`, `negated`, `reciprocal`, `=`, `<`, `asFloat`, `printString`, `isFraction`. 47 tests in `lib/smalltalk/tests/numbers.sx`.
- [x] `String>>format:`, `printOn:` for everything. `format:` is a String primitive that walks the source and substitutes `{N}` (1-indexed) placeholders with `(str (nth args (N - 1)))`; out-of-range or malformed indexes are kept literally. `printOn:` is universal: routes through `(st-send receiver "printString" ())` so user overrides win, then `(str ...)` coerces to a real iterable String before sending to the stream's `nextPutAll:`. `printString` for user instances falls back to the standard "an X" / "a X" form (vowel-aware article); for class-refs it's the class name. 18 tests in `lib/smalltalk/tests/printing.sx`. Phase 5 complete.
### Phase 6 — SUnit + corpus to 200+
- [x] Port SUnit (`lib/smalltalk/sunit.sx`). Written in Smalltalk source via `smalltalk-load`. Provides `TestCase` (with `setUp` / `tearDown` / `assert:` / `assert:description:` / `assert:equals:` / `deny:` / `should:raise:` / `shouldnt:raise:` / `runCase` / class-side `selector:` and `suiteForAll:`), `TestSuite` (`init`, `addTest:`, `addAll:`, `tests`, `run`, `runTest:result:`), `TestResult` (`passes`/`failures`/`errors`, counts, `allPassed`, `summary` using `String>>format:`), `TestFailure` (Error subclass raised by assertion failures and caught by the runner). 19 tests in `lib/smalltalk/tests/sunit.sx` exercise pass/fail counts, mixed suites, setUp threading, and should:raise:. test.sh now loads `lib/smalltalk/sunit.sx` in the bootstrap chain (nested SX `(load …)` from a test file does not reliably propagate top-level forms).
- [x] Vendor a slice of Pharo `Kernel-Tests` and `Collections-Tests`. `lib/smalltalk/tests/pharo/kernel.st` (IntegerTest / StringTest / BooleanTest, ~50 methods) and `tests/pharo/collections.st` (ArrayTest / DictionaryTest / SetTest, ~35 methods) hold the canonical Smalltalk source. `lib/smalltalk/tests/pharo.sx` carries the same source as strings (the `(load …)`-from-tests-files limitation we hit during SUnit), runs each test method through SUnit, and emits one st-test row per Smalltalk method — 91 in total.
- [x] Drive the scoreboard up: aim for 200+ green tests. **751 green** at this point — past the target by 3.7x.
- [x] Stretch: ANSI Smalltalk validator subset (`lib/smalltalk/tests/ansi.sx`). 62 tests organised by ANSI X3J20 §6.10 Object, §6.11 Boolean, §6.12 Number, §6.13 Integer, §6.16 Symbol, §6.17 String, §6.18 Array, §6.19 BlockContext. Each test runs through SUnit and emits one st-test row, mirroring the Pharo-slice harness.
### Phase 7 — speed (optional)
- [x] Method-dictionary inline caching. Two layers: (1) global `st-method-cache` (already in runtime, keyed by `class|selector|side`, stores `:not-found` for misses); (2) NEW per-call-site monomorphic IC — each `send` AST node stores `:ic-class` / `:ic-method` / `:ic-gen`, and a hot send with the same receiver class skips the global lookup entirely. `st-ic-generation` (in runtime.sx) bumps on every method add/remove, so cached method records can never be stale. `st-ic-stats` / `st-ic-reset-stats!` for tests + later debugging. 10 dedicated IC tests in `lib/smalltalk/tests/inline_cache.sx`.
- [ ] Block intrinsification beyond `whileTrue:` / `ifTrue:`
- [ ] Compare against GNU Smalltalk on the corpus
## Progress log
_Newest first. Agent appends on every commit._
- 2026-04-25: Phase 7 — per-call-site monomorphic inline cache + 10 IC tests (`lib/smalltalk/tests/inline_cache.sx`). `send` AST nodes carry `:ic-class`/`:ic-method`/`:ic-gen`; `st-ic-generation` bumps on every method-table mutation, invalidating stale entries. 823/823 total.
- 2026-04-25: ANSI X3J20 validator subset + 62 tests (`lib/smalltalk/tests/ansi.sx`). One TestCase subclass per ANSI §6.x protocol; runs through SUnit. **Phase 6 complete.** 813/813 total.
- 2026-04-25: Pharo Kernel-Tests + Collections-Tests slice + 91 pharo-style tests (`tests/pharo/{kernel,collections}.st` + `tests/pharo.sx`). Each Smalltalk test method runs as its own SUnit case and counts as one st-test toward the scoreboard. 751/751 total — past the Phase 6 "200+ green tests" target.
- 2026-04-25: SUnit port (`lib/smalltalk/sunit.sx`, `lib/smalltalk/tests/sunit.sx`) — TestCase/TestSuite/TestResult/TestFailure all written in Smalltalk source via `smalltalk-load`. Full assert family + should:raise: + setUp/tearDown threading. 19 tests verify the framework. test.sh now bootstraps SUnit alongside runtime/eval. 660/660 total.
- 2026-04-25: String>>format: + universal printOn: + 18 tests (`lib/smalltalk/tests/printing.sx`). `format:` does Pharo {N}-substitution; `printOn:` routes through user `printString` and coerces to a String for iteration. Phase 5 complete. 638/638 total.
- 2026-04-25: Number tower + Fraction class + 47 tests (`lib/smalltalk/tests/numbers.sx`). 14 new Number primitives (floor/ceiling/truncated/rounded/sqrt/squared/raisedTo:/factorial/even/odd/gcd:/lcm:/isInteger/isFloat). Fraction with normalisation + arithmetic + comparisons + asFloat. 620/620 total.
- 2026-04-25: Stream hierarchy + 21 tests (`lib/smalltalk/tests/streams.sx`). ReadStream / WriteStream / ReadWriteStream as user classes; class-side `on:`; ReadStream-on-String yields characters. Bumped `test.sh` per-file timeout 60s → 180s — heavier bootstrap pushed `programs.sx` past 60s. 573/573 total.
- 2026-04-25: HashedCollection / Set / Dictionary / IdentityDictionary + 29 tests (`lib/smalltalk/tests/hashed.sx`). Set: dedup add:, remove:, includes:, do:, addAll:. Dictionary: parallel keys/values backing; at:put:, at:ifAbsent:, includesKey:, removeKey:, keysDo:, keysAndValuesDo:. Class-side `new` chains `super new init`. Array primitive `add:` added. 552/552 total.
- 2026-04-25: Phase 5 sequenceable-collection methods + 28 tests (`lib/smalltalk/tests/collections.sx`). 13 shared methods on `SequenceableCollection` (inject:into:, detect:, count:, …), inherited by Array/String/Symbol via `self do:`. String primitives at:/copyFrom:to:/first/last/do:. 523/523 total.
- 2026-04-25: Exception system + 15 tests (`lib/smalltalk/tests/exceptions.sx`). Exception/Error/ZeroDivide/MessageNotUnderstood in bootstrap; signal/signal: raise via SX `raise`; on:do:/ensure:/ifCurtailed: on BlockClosure via SX `guard`. Phase 4 complete. 495/495 total.
- 2026-04-25: `Object>>becomeForward:` + 6 tests. In-place mutation of `:class` and `:ivars` via `dict-set!`; aliases see the new identity. 480/480 total.
- 2026-04-25: `Behavior>>compile:` + sisters + 9 tests. Parses source via `st-parse-method`, installs via runtime helpers; also added `addSelector:withMethod:` and `removeSelector:`. 474/474 total.
- 2026-04-25: `respondsTo:` / `isKindOf:` / `isMemberOf:` + 26 tests. Universal at `st-primitive-send`. 465/465 total.
- 2026-04-25: `Object>>perform:` family + 10 tests. Universal dispatch via `st-send` after `(str (nth args 0))` for the selector. 439/439 total.
- 2026-04-25: Phase 4 reflection accessors (`lib/smalltalk/tests/reflection.sx`, 26 tests). Universal `Object>>class`, plus `methodDict`/`selectors`/`instanceVariableNames`/`allInstVarNames`/`classMethodDict`/`classSelectors` on class-refs. 429/429 total.
- 2026-04-25: conformance.sh + scoreboard.{json,md} (`lib/smalltalk/conformance.sh`, `lib/smalltalk/scoreboard.json`, `lib/smalltalk/scoreboard.md`). Single-pass runner over `test.sh -v`; baseline at 5 programs / 39 corpus tests / 403 total. **Phase 3 complete.**
- 2026-04-25: classic-corpus #5 Life (`tests/programs/life.st`, 4 tests). Spec-interpreter Conway's Life with edge handling. Block + blinker + glider initial setup verified; larger step counts pending JIT (each spec-interpreter step is ~5-8s on a 5x5 grid). Added `{e1. e2. e3}` dynamic array literal to parser + evaluator. 403/403 total.
- 2026-04-25: classic-corpus #4 mandelbrot (`tests/programs/mandelbrot.st`, 7 tests). Escape-time iterator + grid counter. Discovered + fixed an immutable-list bug in `lit-array` eval — `map` produced an immutable list so `at:put:` raised; rebuilt via `append!`. Quicksort tests had been silently dropping ~7 cases due to that bug; now actually mutate. 399/399 total.
- 2026-04-25: classic-corpus #3 quicksort (`tests/programs/quicksort.st`, 9 tests). Lomuto partition; verified across duplicates, already-sorted/reverse-sorted, empty, single, negatives, all-equal, plus in-place mutation. 385/385 total.
- 2026-04-25: classic-corpus #2 eight-queens (`tests/programs/eight-queens.st`, 5 tests). Backtracking search; verified for boards of size 1, 4, 5. Larger boards are correct but too slow on the spec interpreter without JIT — `(EightQueens new size: 6) solve` is ~38s, 8-queens minutes. 382/382 total.
- 2026-04-25: classic-corpus #1 fibonacci (`tests/programs/fibonacci.st` + `tests/programs.sx`, 13 tests). Added `smalltalk-load` chunk loader, class-side `subclass:instanceVariableNames:` (and longer Pharo variants), `Array new:` size, `methodsFor:`/`category:` no-ops, `st-split-ivars`. 377/377 total.
- 2026-04-25: cannotReturn: implemented (`lib/smalltalk/tests/cannot_return.sx`, 5 tests). Each method-invocation gets an `{:active true}` cell shared with its blocks; `st-invoke` flips it on exit; `^expr` raises if the cell is dead. Tests use SX `guard` to catch the raise. Non-`^` blocks unaffected. 364/364 total.
- 2026-04-25: `ifTrue:` / `ifFalse:` family pinned (`lib/smalltalk/tests/conditional.sx`, 24 tests) + parser fix: `|` is now accepted as a binary selector in expression position (tokenizer still emits it as `bar` for block param/temp delimiting; `parse-binary-message` accepts both). Caught by `false | true` truncating silently to `false`. 359/359 total.
- 2026-04-25: `whileTrue:` / `whileFalse:` / no-arg variants pinned (`lib/smalltalk/tests/while.sx`, 14 tests). `st-block-while` returns nil per ANSI; behaviour verified under captured locals, nesting, early `^`, and zero/many iterations. 334/334 total.
- 2026-04-25: BlockContext value family pinned (`lib/smalltalk/tests/blocks.sx`, 19 tests). Each value/valueN/valueWithArguments: variant verified plus closure semantics (read, write, later-mutation re-read), nested blocks, and block-as-arg. 320/320 total.
- 2026-04-25: **THE SHOWCASE** — non-local return via captured method-return continuations + 14 NLR tests (`lib/smalltalk/tests/nlr.sx`). `st-invoke` wraps body in `call/cc`; blocks copy creating method's `^k`; `^expr` invokes that k. Verified across nested blocks, `to:do:` / `whileTrue:`, blocks passed to different methods (Caller→Helper escapes back to Caller), inner-vs-outer method nesting. Sentinel-based return removed. 301/301 total.
- 2026-04-25: `super` send + 9 tests (`lib/smalltalk/tests/super.sx`). `st-super-send` walks from defining-class's superclass; class-side aware; primitives → DNU fallback. Also fixed top-level `| temps |` parsing in `st-parse` (the absence of which was silently aborting earlier eval/dnu tests — counts go from 274 → 287, with previously-skipped tests now actually running).
- 2026-04-25: `doesNotUnderstand:` + 12 DNU tests (`lib/smalltalk/tests/dnu.sx`). Bootstrap installs `Message` (with selector/arguments accessors). Primitives signal `:unhandled` instead of erroring; `st-dnu` builds a Message and walks `doesNotUnderstand:` lookup. User Object DNU intercepts unknown sends to native receivers (Number, String, Block) too. 267/267 total.
- 2026-04-25: method-lookup cache (`st-method-cache` keyed by `class|selector|side`, stores `:not-found` for misses). Invalidation on define/add/remove + bootstrap. `st-class-remove-method!` added. Stats helpers + 10 cache tests; 255/255 total.
- 2026-04-25: `smalltalk-eval-ast` + 60 eval tests (`lib/smalltalk/eval.sx`, `lib/smalltalk/tests/eval.sx`). Frame chain with mutable locals/ivars (via `dict-set!`), full literal eval, send dispatch (user methods + native primitive tables for Number/String/Boolean/Nil/Array/Block/Class), block closures, while/to:do:, cascades returning last, sentinel-based `^return`. User Point class round-trip works including `+` returning a fresh point. 245/245 total.
- 2026-04-25: class table + bootstrap (`lib/smalltalk/runtime.sx`, `lib/smalltalk/tests/runtime.sx`). Canonical hierarchy, type→class mapping for native SX values, instance construction, ivar inheritance, method install with `:defining-class` stamp, instance- and class-side method lookup walking the superclass chain. 54 new tests, 185/185 total.
- 2026-04-25: chunk-stream parser + pragmas + 21 chunk/pragma tests (`lib/smalltalk/tests/parse_chunks.sx`). `st-read-chunks` (with `!!` doubling), `st-parse-chunks` state machine for `methodsFor:` batches incl. class-side. Pragmas with multiple keyword pairs, signed numeric / string / symbol args, in either pragma-then-temps or temps-then-pragma order. 131/131 tests pass.
- 2026-04-25: expression-level parser + 47 parse tests (`lib/smalltalk/parser.sx`, `lib/smalltalk/tests/parse.sx`). Full message precedence (unary > binary > keyword), cascades, blocks with params/temps, literal/byte arrays, assignment chain, method headers (unary/binary/keyword). Chunk-format `! !` driver deferred to a follow-up box. 110/110 tests pass.
- 2026-04-25: tokenizer + 63 tests (`lib/smalltalk/tokenizer.sx`, `lib/smalltalk/tests/tokenize.sx`, `lib/smalltalk/test.sh`). All token types covered except scaled decimals `1.5s2` (deferred). `#(` and `#[` emit open tokens; literal-array contents lexed as ordinary tokens for the parser to interpret.
## Blockers
_Shared-file issues that need someone else to fix. Minimal repro only._
- _(none yet)_