Lyric

A statically typed application language with a bytecode VM — standalone, and embeddable in a host with a capability-based sandbox.

What changed in v3.3.0 — 2026-08-24

Fixed

A module that only CALLS through an interface no longer fails to load. A library — an interface, a class calling through it, and the implementing left to whoever imports it — produced a .lyrbc its own loader refused:
```
function 'kit.props.Field.take' at 70: stack depth 5 exceeds the declared maximum of 4
```
The bytecode was correct. The loader reads a callvirt's argument count off an Impls row, because every implementation of a slot shares its signature and the Types section carries slot names alone; with nothing implementing the interface there is no row, and the missing count was answered with "no arguments, no result". A two-argument call then looked as though it left its arguments on the stack, which is why the message named a function far from the call and moved when unrelated statements were deleted.

Such a call cannot execute — mkiface is already refused without a row for exactly that pair, so no value of the interface can exist — and the loader now says so by stopping rather than guessing: everything up to the call is checked, and the rest of that block is not claimed to be. Where a row exists nothing changes.
Iterating an array of optionals is a message, not a crash (LYR-SEM0091). for (h in houses) over a (?House)[] — an ordinary table shape — crashed the compiler in debug (optnone of ?i64 — optionals do not nest, with a stack trace and no position) and, in release, made check answer "ok" for a program build could not finish.

The cause is the protocol, not the container: next() answers ?T and uses null to mean "the end", so an optional element would need ??T to be told apart from it, and ? does not nest. The message says that and points at the loop that does work — over the indices. It fires the same way for an iterator of optionals handed in directly, because the reason is the same.
An operator whose operand already reported stays silent. <error>[] appeared in sentences about operators: IsError was consulted where the error sat INSIDE an array or a tuple, so the type was not itself the error and the check went on to complain about it.
A range outside a loop head is a message, not a crash (LYR-SEM0090). let r = 1..5; and [1..3] threw an internal exception out of the lowering, with a stack trace and no source position. A range is a loop head and not a value — the grammar has no range expression among its primaries and there is no range type — but nothing said so where the type was INFERRED; where it was written down, the assignment had refused it all along. The grammar now names the form and its one legal position.
The compiler reads back every module it writes. The emit step was taken for mechanical, so nothing checked it: a .lyrbc its own loader refuses was found by a golden-image test that opened a window, two layers from the change. The bytes now go through the loader before a build writes them, in release as in debug — the one time it mattered, compiler and runtime were the same released build. A module that fails is a compiler bug and is reported as one, with the loader's own words.
An aliased import used only as a TYPE is no longer reported as unused. import kit.eye as look; mentioned once, as eye: look.Eye, warned LYR-SEM0072 — a build error under --deny-warnings. The qualifier of a type path has no node of its own, so neither reference table carried it; the resolver records the step-through now. A plain import used as a type and an alias used in an expression were already counted, which is what made the gap read as arbitrary.
LYR-IR0001 says one sentence instead of two grown together. The category was appended as a clause, and where a message ended in a subordinate one the result was "initializer omits field 'wood', which has no default is not supported by this compiler version yet". The message names the construct; the category is a note beneath it.
A keyword written where a name belongs says so. keep.resume(); reported expected member name after '.', got Resume — the way a parser talks about a typo, which costs a reader a look at the spelling before they suspect the word. The identifier expectations now carry a note:
```
note: 'resume' is a keyword and cannot be used as a name
```
Only those: got Return where a ; was expected is not a naming problem.

Added

lyric check <file> --emit answers the question plain check cannot: not "does this program compile" but "does the module it produces LOAD". It emits, reads back, and writes nothing. For a project that compiles every one of its files as an entry — to read each file's attributes — that was the missing invariant.

The full changelog →