Lyric

What changed in v1.10.0 — 2026-08-19

The compiler learns to speak below "error". Four severities, warnings that matter, notes that point at places, and a CI gate. The language, the bytecode format (3.2) and the embedding API are unchanged; every program that compiled still compiles — some now hear about themselves.

Added

• Warnings. A local binding, loop variable, catch binding or pattern binding that is never referenced (LYR-SEM0071 — naming it _ is the opt-out; parameters and the shorthand field pattern Rect { w, h } are deliberately exempt). An imported name nobody in the file uses (LYR-SEM0072). A statement control flow can never reach (LYR-SEM0073). And a static extension method called through an instance (LYR-SEM0074): that form is deprecated and becomes an error in the next major — the warning is the clock. Warnings stay silent over a program with errors, and never fail a build by themselves.

• --deny-warnings on check and build, for CI: the warnings keep their severity in the output, one closing error (LYR-CLI0016) carries the policy into the exit code, and a denied build writes no artifact. The lyric.json unknown-key warnings are real diagnostics now (LYR-CLI0017) and count toward the gate.

• Notes on diagnostics. A duplicate declaration points back at the first one, a missing interface method points at the member it fails (in whatever file it lives), an unknown name suggests the single closest candidate in scope, and an unknown member suggests from the same list completion offers. Rendered indented under the caret block in text — deliberately not in the head-line format a problem matcher reads — as a notes array in --json (only when present, so existing consumers read what they always read), and as related information in editors.

• The first hint. LYR-SEM0075: a var through which nothing is ever changed — no reassignment, no field or element write, no mut call, not handed over by reference — could be a let. A var that documents mutation keeps its var.

• An error that was silent misbehavior: two files claiming one module name is LYR-RES0007 with a note at the first claim, instead of a shadow registration nothing could explain.

• Editors draw the difference: unused and unreachable code fades, the deprecated instance form is struck through, and every note is a click away. The severity info exists on the wire for what later versions will say at it.

• Guide chapter 19 documents the contract: severities, codes as stable identifiers, the gate, and what warns today. The repository holds itself to it — the standard library, the examples and the templates check in silence, and a test keeps them there.

Changed

• The editor clients live in their own repositories (vscode-lyric, jetbrains-lyric) and release their installables there, on their own cadence. Toolchain releases v1.8.0 through v1.9.1 carried them beside the archives; from this release on they are found there. The project moved to the lyriclang organization.

• Two messages stopped promising futures: the duplicate-function hint lost its "in v1" (overloading was rejected for good in v1.5.0), and the block-lambda limit LYR-SEM0046 now states the problem in the message and its way out in a note.

The full changelog →