1.10.0

Nine semantic passes each carried their own recursive walk over the compiler's tree, and every one of them ended in a permissive default — so a node kind a pass did not name was skipped in silence. A source review asked whether @hot was complete. It was not, and neither was anything else built the same way: five programs compiled clean and failed at run time, and two inference passes let @deterministic and a system's declared access pass for code that violated both.

The five, all of which shipped:

• a task local read inside [a, b] or xs[i] emitted a bare identifier — a ReferenceError on the first resume that reached the line;
• a let inside a for loop in a task was written to the frame and read from a scope;
• an emit inside a for loop compiled to $rt.emit(…) in a module that declared no $rt and exported no __runtime;
• a ? inside a for loop or a scope left its function unwrapped, so the internal carrier object escaped instead of becoming an Err;
• @hot accepted a list literal, an allocation anywhere in a loop body, and anything reached through a condition, an ifLet subject, an index subscript, a spawn argument or an event payload.

ir/walk.ts and astWalk.ts are the one description of what a node contains now, both exhaustive on never. A pass that only recurses asks them and names no kind, so a node added later is walked correctly without it changing; a pass making a claim about a kind — what allocates, how to rebuild a node — keeps its own switch and ends it on never, because a claim has no safe default. walkers.test.ts asserts the matrix by nested position rather than by feature.

await inside for … in used to throw a bare internal error from the emitter, and now it works. The cutter splits a list loop the way it already split a while, with the list and the index on the frame. A continue lands on the increment rather than the loop head, because one that jumped to the head would re-bind the same element for ever — a task alive, resuming, and making no progress. A query loop still refuses to suspend, and now refuses however deeply the await is nested.

i64 and u64 claimed a range the backend cannot represent. A JavaScript number is a double: exact to 2^53 - 1 and no further. The bounds were computed as 2 ** 64 - 1, which is 2^64 as a double, so nothing was ever outside a u64 and sums went on running with bits already lost. Their domain is now -(2^53 - 1) … 2^53 - 1 and 0 … 2^53 - 1; the nominal width still means what it says wherever a value is stored, which is why the types stay. Wrapping is refused on both by name, since two values near the top add to almost 2^54 where the sum is rounded before anything can reduce it; checked and saturating arithmetic are untouched. A literal is now checked against its type at every width — let n: u8 = 300 compiled before this — and a negative literal is checked after its sign is applied, which was wrong in both directions.

A live task is rebound only when its frame and its resume points agree. A suspended task was being handed to new code on its exported name alone. Each task now emits its frame layout and the shape of its suspensions, and patchModule plans every live task before the first write and refuses atomically. Body edits, duration changes and added or removed locals are carried; a type change or a moved await is refused, naming what it is. The package README has the table.

typeKey returned type.kind for anything it did not special-case, so every integer width keyed as int, every enum as enum and every list as list — and callers compare it for equality. A migration would carry a u8 into an i64, an interface change from u8 to i64 hashed identically, and, because a component field's type is this string while a host's column table is keyed by the width, every integer component field threw at bind. Nothing in the corpus declares one, which is why it stood.

A module specifier is serialised rather than quoted. The parser keeps whatever sits between the quotes and a filesystem host resolves it as a path, so a directory holding an apostrophe produced generated JavaScript that would not parse. AGENTS.md carries the rule this generalises to.

A mode: 'production' build is refused without a manifest and a registry, unless verification: 'none' says it is deliberately unverified. Without them nothing links and @deterministic is a claim nothing checked, and that was the shortest working config. Development is unchanged.

The fixed simulation step is a target's, not the parser's. CompileOptions.fixedStepsPerSecond defaults to 60; DS0133 lists the rates that divide your step, and the value a module was built with rides in its metadata, so a module cached at 30 and loaded by a host running at 60 can be told apart from one built for it.

SECURITY.md now separates capability enforcement from execution isolation: the model controls what a script may name, and gives no CPU budget, no memory quota and no containment. Untrusted content belongs in a Worker with capabilities passed across it.