weir-ports

Real-world programs ported to weir — a typed, shell-shaped scripting language. Each port is a language stress test: the working code proves weir can carry the program, and the FINDINGS.md alongside it is the honest engineering account of what read better than the original, what forced a redesign, and what weir was missing (that list has driven real language features — Str.fields, Bytes.hmacSha256, dynamic command heads, and more).

Every port is checked and tested against the weir release pinned in TARGET_WEIR_RELEASE; CI installs exactly that release and runs it, so a red build is the migration-work signal for the next release (the same currency pattern tree-sitter-weir uses).

The ports

Port	From	Surface it exercises	Headline
asdf/	asdf (bash version manager, pre-Go)	files · process · PATH · plugins-as-programs	core commands at ~half the bash line count (1265 → 657); .tool-versions parses once into a typed value
acme/	acme.sh (ACME/Let's Encrypt client)	HTTP · JSON · Bytes/base64url · crypto	HTTP layer 230 → 33 lines; JWS envelope openssl-oracle-verified; RFC-7638 thumbprints byte-match
ring/	ring (.NET process orchestrator)	supervision · concurrency · lifecycle · signals	a process supervisor on Proc.spawn/poll; the FSM as a 30-line match; state file-backed → status from a second process, no server
dbt/	dbt (arquidevio monorepo build tool, F#)	monorepo discovery · git-diff change detection · CE-DSL → records · from xml	the plan{} computation-expression DSL → plain records (~40% fewer lines, "a plan is just a value"); real-dbt oracle byte-identical; Graph.reach eats the 4th hand-rolled walk-up; the plan-keyword collision (dbt's build-Plan vs weir's dry-run plan)

Each is a Stage 1 slice — a coherent, runnable proof, not a complete port — with a Stage-2 estimate in its FINDINGS.

What the ports taught the language

The findings are the point. A sample of gaps these ports surfaced, most now closed:

• Dynamic command heads (^$path arg) — asdf's plugin callbacks are runtime paths; the literal-head rule forced sh -c, the injection vector weir exists to abolish. Now a first-class, injection-safe form.
• Str.fields/Str.rsplit, Bytes.fromHex/toHex/hmacSha256, Seq.equal, Str.padLeft/padRight — each hand-rolled in a port before it was a member.
• Non-tty SIGINT (ring) — scopes unwind on Ctrl+C at a tty but a piped process ignored the signal; a supervisor-critical fix.
• A server surface (ring) — the protocol study proved Http.serve + SSE-as-a-lazy-seq covers a real orchestrator's protocol without WebSockets.

Each port also caught bugs in the original — the typed rewrite makes latent logic errors obvious (asdf's version-starring, ring's unpassed compose env).

Running a port

curl -fsSL https://weir.sh/install.sh | sh   # installs the latest weir
cd asdf && weir check bin/asdf.weir     # typecheck (runs nothing)
weir test/run.weir                      # the port's own harness

The pinned release is the contract: weir --version should be at least TARGET_WEIR_RELEASE.