SX's (str 1e-7) gives "1e-07" but JS spec is "1e-7" — no padding, no
leading zeros in the exponent (sign stays). We stepped through:
mant "e" expraw → mant "e" (sign (strip-zeros body))
Added four small helpers: js-normalize-num-str, js-split-sign,
js-strip-leading-zeros, js-strip-zeros-loop. All pure string walkers.
Unit 521/522, slice 148/148 unchanged.
String 40 → 42, Number 75 → 76 (+3 total).
Fixes S9.8.1_A9_T1, fromCharCode/S9.7_A3.1_T1..T2 family.
Tests expected Function.prototype.isPrototypeOf(Number/String/…) ===
true because every built-in ctor inherits from Function.prototype.
Our model doesn't link Number.__proto__ anywhere, so the default
Object.isPrototypeOf walked an empty chain and returned false.
Fix: post-definition dict-set! adds an explicit isPrototypeOf override
on js-function-global.prototype that returns (js-function? x) — which
accepts lambdas, functions, components, and __callable__ dicts. Good
enough to satisfy the spec for every case that isn't a bespoke proto
chain.
Unit 521/522, slice 148/148 unchanged.
Wide scoreboard: 156/300 → 159/300 (+3, Number/S15.7.3_A7 and the
three S15.5.3_A2 / S15.6.3_A2 / S15.9.3_A2 twins).
Every built-in JS function on Math/Number/Array/Object had .name === ""
because js-invoke-function-method/js-get-prop returned bare "" for the
"name" slot. That breaks tests like Math.abs.name === "abs" and
Array.isArray.name === "isArray".
Fix: extract the SX symbol name from (inspect fn) which prints
<js-math-abs(x)>, then unmap through a small string table that maps
js-math-abs → "abs", js-array-is-array → "isArray" etc. Also strips
the angle-bracket marker and stops at ( or space.
Non-mapped lambdas (user fns) fall through to the raw "js-foo" form
rather than "", which is slightly worse but only hit in debug prints.
Unit 521/522, slice 148/148 unchanged.
Scoreboard: Math 40/100 → 43/100 (+3); Number 74 → 75 (+1).
Sample: Math/abs/name.js, Math/floor/name.js, Math/max/name.js,
Number/isNaN/name.js — all flipped. length.js tests still fail for
trig because the underlying fn isn't implemented.
js-number-to-string did (str n), which gives OCaml-native "inf"/"-inf"/
"nan"/"-nan" strings. JS spec requires "Infinity"/"-Infinity"/"NaN".
Fix: cond-check js-number-is-nan, and =infinity-value first, fall
through to (str n) for finite.
Unit 521/522, slice 148/148 unchanged.
String scoreboard: 34/100 → 38/100 (+4, S15.5.1.1_A1_T11/T12 family —
String(1/0)/String(-1/0)/String(0/0)).
Previously a JS function body with no return fell through the call/cc
begin as nil, making `(function(){}())` return null and typeof → object.
Spec: falls-off-end gives undefined.
Wrap the call/cc in (let ((__r__ ...)) (if (= __r__ nil) :js-undefined __r__)).
Downside: explicit `return null` also returns nil, but so does (pick
your last expression evaluating to null). For 99% of cases it's
fall-off-end and the fix is correct. Code that genuinely needs
distinguishable null would need separate nil/undef handling in the
evaluator.
Unit 521/522, slice 148/148 unchanged.
Number 73/100 → 74/100 (+1), String 33/100 → 34/100 (+1).
Fixes S15.5.1.1_A1_T1 family (String(function(){}()) should be "undefined").
ES spec: ToNumber("0x0") == 0, ToNumber("0xFF") == 255. Our parser
returned NaN for anything with a 0x/0X prefix, failing S9.3.1_A16..A32
(every hex-literal assertion test case).
Added:
- js-hex-prefix? — is this an 0x/0X prefix?
- js-is-hex-body? — all remaining chars are [0-9a-fA-F]?
- js-parse-hex — walk chars, accumulate in base 16, NaN on bad char
- js-hex-digit-value — char → 0..15 (or -1)
js-is-numeric-string? short-circuits to the hex-body check on 0x*
prefix; js-num-from-string dispatches to js-parse-hex on same.
Unit 521/522, slice 148/148 unchanged.
Number scoreboard: 58/100 → 73/100 (+15).
Sample flipped: S9.3.1_A16 (0x0/0X0), A17..A31 (0x0..0xF and 0x10..0x1F
range coverage). Many of the remaining 22 fails are (new Number()).x
style prototype-chain introspection and MAX_VALUE precision.
js-get-ctor-proto used to always synthesise a per-ctor-id empty dict in
__js_proto_table__, ignoring the :prototype slot that every built-in
constructor dict (Number, String, Array, Boolean, Object, Function)
already carries. So `new Number()` got `{__proto__: {}}` instead of
`{__proto__: Number.prototype}`, breaking every prototype-chain-method
lookup:
(new Number()).toLocaleString // undefined → function
(new Number()).toLocaleString === Number.prototype.toLocaleString
Fix: when the receiver is a dict with a "prototype" key, return that
directly; otherwise fall through to the existing proto-table path.
Declared classes from JS still go through the table because they emit
js-set-ctor-proto! at definition.
Unit 521/522, slice 148/148 unchanged.
Number scoreboard: 53/100 → 58/100 (+5). Sample: S15.7.5_A1_T03..T07
(toLocaleString/toString/toFixed/toExponential prototype identity).
Six post-definition dict-set! calls add .length=1 and .name="<Ctor>"
to the global constructor dicts. Per spec Number/String/Array/Boolean/
Object all have length 1 (they take one arg).
Unit 521/522, slice 148/148 unchanged.
Number scoreboard: 52/100 → 53/100 (+1, S15.7.3_A8: Number.length==1).
Root cause of many Number/String/Object.hasOwnProperty false-negatives:
global dicts like Number/String/Object carry a :__callable__ slot so
they can be invoked (Number(5) coerces, Array(3) makes length-3 list).
That makes js-function? return true for them, so js-invoke-method
dispatched hasOwnProperty/isPrototypeOf/propertyIsEnumerable through
js-invoke-function-objproto (whose name/length/prototype-only check
returns false for real dict keys like MAX_VALUE).
Fix: in the invoke-method cond, exclude dicts from the function-proto
branch. Callable dicts fall through to js-invoke-object-method, which
walks (keys recv) properly.
One line in a compound `and` — minimal surface, easy to revert.
Unit: 521/522 unchanged.
Conformance: 148/148 unchanged.
Number scoreboard: 46/100 → 52/100 (+6).
Impacted sample: Number.hasOwnProperty("MAX_VALUE") → true (was false),
plus S15.7.3_A2..A8 family (MAX_VALUE/MIN_VALUE/POSITIVE_INFINITY/
NEGATIVE_INFINITY existence checks) and S15.7.2.1_A2..A4.
js-num-from-string now finds an e/E split, parses mantissa and exponent
separately, and combines via js-pow-int (positive-exp loop for >=0, 1/
reciprocal for negative). Previously `.12345e-3` parsed as 0.12345 and
"1e3" returned NaN — the parser walked decimals/dots only.
New helpers:
- js-find-exp-char / -loop : linear scan for e/E, returns -1 if absent
- js-pow-int base exp : integer-exp power, handles negative
Also fixed `js-string-trim` typo → `js-trim` in the rewritten num-from-
string, and corrected test 903's expected part count (3, not 2 — the
lexer has always split `hi ${x}!` into str+expr+str, the test just had
the wrong count).
Unit: 521/522 (was 520/522, 934 still blocked on SX \` escape).
Conformance: 148/148 unchanged.
Number scoreboard: 43/100 → 46/100 (+3).
Impacted test262 paths (sample): built-ins/Number/S9.3.1_A11.js and
A12/A16/A17 (".12345e-3", scientific notation round-trips).
Root cause: every sx_server worker session used js-eval on the 3.6KB
HARNESS_STUB, paying ~15s for tokenize+parse+transpile even though every
session does the same thing. Over a full scoreboard with periodic worker
restarts that's minutes of wasted work.
Fix: transpile once per Python process. Spin up a throwaway sx_server,
run (inspect (js-transpile (js-parse (js-tokenize HARNESS_STUB)))), write
the resulting SX source to lib/js/.harness-cache/stub.<fingerprint>.sx and
a stable-name symlink-ish copy stub.sx. Every worker session then does a
single (load .harness-cache/stub.sx) instead of re-running js-eval.
Fingerprint: sha256(HARNESS_STUB + lexer.sx + parser.sx + transpile.sx).
Transpiler edits invalidate the cache automatically. Runs back-to-back
reuse the cache — only the first run after a transpiler change pays the
~15s precompute.
Transpile had to gain a $-to-_js_dollar_ name-mangler: the SX tokenizer
rejects $ in identifiers, which broke round-tripping via inspect. JS
$DONOTEVALUATE → SX _js_dollar_DONOTEVALUATE. Internal JS-on-SX names are
unaffected (none contain $).
Measured: 300-test wide (Math+Number+String @ 100/cat, --per-test-timeout 5):
593.7s → 288.0s, 2.06x speedup. Scoreboard 114→115/300 (38.3%, noise band).
Math 40%, Number 44%, String 30% — same shape as prior.
Baselines: 520/522 unit, 148/148 slice — unchanged.
Mirrors the existing Error/TypeError/RangeError/SyntaxError/ReferenceError
shims. Each sets .message and .name on the new object. Unblocks tests
that use these error types in type-check assertions.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Several tests check 'new Function("return 1")' — we can't actually
implement that (would need runtime JS eval). Now Function is a dict with
__callable__ that throws TypeError, and a prototype containing call/apply/
bind/toString/length/name stubs so code that probes Function.prototype
doesn't crash with 'Undefined symbol: Function'.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
JS 'globalThis' now rewrites to SX (js-global) — the global object dict.
JS 'eval' rewrites to js-global-eval, a no-op stub that echoes its first
arg. Many test262 tests probe eval's existence or pass simple literals
through it; a no-op is better than 'Undefined symbol: eval'.
A full eval would require plumbing js-eval into the runtime with access
to the enclosing lexical scope — non-trivial. The stub unblocks tests
that just need eval to be callable.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
String.prototype.toUpperCase.hasOwnProperty('length') was failing with
'TypeError: hasOwnProperty is not a function' because js-invoke-method's
dict-with-builtin fallback only matched 'dict' receivers, not functions.
New js-invoke-function-objproto branch handles hasOwnProperty (checks
name/length/prototype keys), toString, valueOf, isPrototypeOf,
propertyIsEnumerable, toLocaleString. Fires from js-invoke-method when
recv is js-function? and key is in the Object.prototype builtin set.
Unblocks many String.prototype tests that check
.hasOwnProperty('length') on the prototype methods.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Before, Object.prototype was {} — tests writing
Object.prototype.hasOwnProperty.call(o, 'x') failed with 'TypeError: call
is not a function' because hasOwnProperty was undefined on the prototype.
Now Object.prototype.hasOwnProperty / .isPrototypeOf / .propertyIsEnumerable
/ .toString / .toLocaleString / .valueOf all exist. They dispatch on
(js-this) so Array.prototype.X.call-style calls work.
Unblocks String.prototype.* tests that set up '__instance = new Object(true)'
and then probe __instance.hasOwnProperty.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Adds __callable__ to the Object global dict: zero args returns {}, one-arg
returns the arg (which mirrors spec ToObject for non-null/undefined). This
unblocks many test262 tests that write 'new Object(true)' or 'Object(5)'
— they were failing with 'Not callable: {:entries ...}' because Object
was a plain dict with no call protocol.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Previously fn.length always returned 0 — so the 'length value' test262 tests
failed. Now js-fn-length inspects the lambda's parameter list (via
lambda-params primitive) and counts non-rest params. For functions/components
and callable dicts it still returns 0 (can't introspect arity in those cases).
6 new unit tests, 520/522 total.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Number dict was missing parseInt/parseFloat members and had MAX_VALUE=0
because SX parses 1e308 as 0 (exponent overflow). Now MAX_VALUE is computed
at load time by doubling until the next step would be Infinity
(js-max-value-approx returns 2^1023-ish, good enough as a finite sentinel).
POSITIVE_INFINITY / NEGATIVE_INFINITY / NaN now also use function-form values
(js-infinity-value, js-nan-value) so we don't depend on SX's inf/-inf/-nan
being roundtrippable as literals.
js-number-to-fixed now returns 'NaN' / 'Infinity' / '-Infinity' for
non-finite values. Also handles negative numbers correctly via |scaled|.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Many test262 tests write 'assert(condition, msg)' as a plain call, not
'assert.sameValue(...)'. The stub now sets assert.__callable__ to
__assert_call__ so the dispatch in js-call-plain finds a callable.
Also widens verifyNotEnumerable etc. to 5-arg signatures — some tests call
them with (o, name, value, writable, configurable).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
js-get-prop on a function receiver only routed .prototype before; now also
handles .name (returns ''), .length (returns 0), and .call/.apply/.bind
as bound function references.
Previously Math.abs.length crashed with 'TypeError: length is not a function'.
Similarly for arr.sort.call which is a common test262 pattern.
Pass rate stable at 514/516.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Four coercion fixes that together unblock many test262 cases:
1. js-to-number(undefined) now returns NaN (was 0). Fixes Number(undefined),
isNaN(undefined), Math ops on undefined.
2. js-string-to-number returns NaN for non-numeric strings (via new
js-is-numeric-string?). Previously returned 0 for 'abc'.
3. parseInt('123abc', 10) → 123 (walks digits until first invalid char),
supports radix 2..36.
4. parseFloat('3.14xyz') → 3.14 (walks float prefix).
5. encodeURIComponent / decodeURIComponent / encodeURI / decodeURI —
new URI-helper implementations.
8 new unit tests, 514/516 total.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Array.from({length: 3, 0: 'a', 1: 'b', 2: 'c'}) used to return ['3','a','b','c']
because js-iterable-to-list walked dict keys in insertion order and included
the 'length' key as a value.
Now the dict branch checks for 'length' key first — if present, delegates to
js-arraylike-to-list which reads indices 0..length-1. Otherwise falls back
to value-order for plain objects.
Fixes Array.from, spread (...dict), and destructure from array-likes.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
The js-array-method / js-string-method dispatch tables had the new methods,
but the Array.prototype and String.prototype dicts that feed
Array.prototype.X.call(...) only had the original set. Now they include
all: Array.prototype.{at,unshift,splice,flatMap,findLast,findLastIndex,
reduceRight,toString,toLocaleString,keys,values,entries,copyWithin,
toReversed,toSorted,lastIndexOf}, and String.prototype.{at,codePointAt,
lastIndexOf,localeCompare,replaceAll,normalize,toLocale*Case}.
Also adds String.raw (trivial stub).
No unit test additions — these methods already tested via direct calls
on instances. 506/508 unchanged.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Previously NaN / Infinity were SX symbols that couldn't be (define)'d
because the SX tokenizer parses 'NaN' and 'Infinity' as numeric literals.
js-transpile-ident now rewrites NaN -> (js-nan-value), Infinity ->
(js-infinity-value), each a zero-arg function returning the appropriate
IEEE value ((/ 0.0 0.0) and (/ 1.0 0.0)).
Also fixes js-number-is-nan: in this SX, (= nan nan) returns true, so the
classic 'v !== v' trick doesn't work. Now checks (inspect v) against
'nan'/'-nan' strings.
Extends js-strict-eq: NaN === NaN returns false per ES spec.
8 new unit tests, 497/499 total.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
New read-only methods added:
- at(i) — negative-index aware
- flatMap(f) — map then flatten one level
- findLast(f) / findLastIndex(f)
- reduceRight(f, init?)
- toString / toLocaleString — join with ','
- keys() / values() / entries() — index/value/pair lists
- copyWithin(target, start, end) — in-place via set-nth!
- toReversed() / toSorted() — non-mutating variants
Mutating methods (unshift, splice) are stubs that return correct lengths
but don't mutate — we don't have a pop-first!/clear! primitive to rebuild
the list in place. Tracked as a runtime limitation.
10 new unit tests, 479/481 total. Directly targets the 785x
ReferenceError in built-ins/Array and the many .toString() crashes.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
js-invoke-method now branches on (number? recv) and (boolean? recv) before
falling through to the generic dict/fn path. js-invoke-number-method handles
toString (incl. radix 2-36), toFixed, valueOf, toLocaleString, toPrecision,
toExponential. js-invoke-boolean-method handles toString and valueOf.
Numbers had no .toString() on bare values before — (5).toString() crashed
with 'TypeError: toString is not a function'. This is one of the bigger
scoreboard misses on built-ins/Number category.
10 new unit tests, 469/471 total.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
classify_error now catches 'unexpected token', 'unexpected char',
'expected ident/punct/keyword' as SyntaxError variants.
classify_negative_result maps parser errors to SyntaxError for negative:parse
tests that expect a SyntaxError. Also maps 'undefined symbol' to
ReferenceError for negative:runtime tests. This reclassifies ~39+36 tests
per wide run from 'fail' to 'pass (negative)'.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Array.prototype.slice.call({length:3, 0:41, 1:42, 2:43}) used to crash with
'Not callable: {dict}' because js-array-proto-fn passed the dict straight
into js-invoke-method, which then tried (append! dict x) etc.
Now js-array-proto-fn converts dict-with-length receivers to a list via
js-arraylike-to-list before dispatch. Mutation methods (push/pop/shift/
reverse/sort/fill) still require a real list — array-likes only work for
read-only methods.
Targets the 455x 'Not callable: {:length N :0 v1 :1 v2 ...}' scoreboard item.
6 new unit tests, 459/461 total.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
{0: 41, 1: 42} was raising 'dict-set!: dict key val' because the parser
kept numeric keys as numbers in the entry dict, but SX dicts require string
keys. Now we str-coerce number-type tokens during jp-parse-object-entry.
Unblocks a huge chunk of test262 array-like-receiver tests that build
{length: N, 0: v, 1: v, ...} literals.
3 new tests, 453/455 total.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Adds js-invoke-function-method dispatched from js-invoke-method when the
receiver is a JS function (lambda/function/component/callable-dict) and the
method name is one of call/apply/bind/toString/name/length.
call and apply bind this around a single call; bind returns a closure with
prepended args. toString returns the native-code placeholder.
6 unit tests, 450/452 total (Array.prototype.push.call with arrayLike still
fails — tracked as the 455x 'Not callable array-like' scoreboard item which
needs array methods to treat dict-with-length as a list).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Rework test262-runner.py to support --workers N parallel shards, each running
a long-lived sx_server session. Replace thread-per-readline with a select-based
raw-fd line buffer.
On 2-core machines, 1 worker still beats 2 (OCaml eval is CPU-bound and starves
when shared). Auto-defaults n_workers=1 on <=2 CPU, nproc-1 (up to 8) otherwise.
Throughput baseline: ~1.1 Math tests/s serial on 2-core (unchanged; the
evaluator dominates). The runner framework is now ready to scale on bigger
machines without further code changes.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
js-transpile-unop intercepts 'delete' before transpiling the
operand. Maps to (js-delete-prop obj key) for members and indexed
access. Runtime js-delete-prop sets the dict value to js-undefined
and returns true.
444/446 unit (+2), 148/148 slice unchanged.
Each prototype contains method-name → closure pairs. Each closure
reads this via js-this and dispatches through js-invoke-method.
Lets Array.prototype.push, String.prototype.slice etc. be accessed
and invoked as (expected) functions.
440/442 unit unchanged, 148/148 slice unchanged.
Array destructure now supports [a, ...rest]. Rest entry is
transpiled to (define name (js-list-slice tmp i (len tmp))).
Nested patterns like [[a,b], c] now parse (as holes) instead of
erroring. jp-skip-balanced skips nested groups.
440/442 unit (+2), 148/148 slice unchanged.
