0005 — Clojure on the JVM only

Status: accepted

Decision

quint-connect targets Clojure on the JVM. ClojureScript is not supported, not partially supported, and not planned. Source files are .clj, not .cljc.

Why

Two reasons, and the second is the decisive one.

Scope. Supporting ClojureScript would have meant reader conditionals in the JSON and process-spawning layers, a second test pipeline, a node build, a browser-only degraded mode, and a class of bug that only appears on one platform — all before the first useful feature existed.

The wiring design requires it. The mapping from spec to implementation is declared with var metadata and read back by scanning namespaces (0002-metadata-wiring.md). ClojureScript has no ns-interns at runtime; namespaces are not reified objects you can enumerate. So the declarative style this project is built around is JVM-only by construction. Given a choice between the wiring design and cross-platform support, the wiring design won, and this ADR records that trade deliberately rather than leaving it implicit.

What it buys

• ns-interns + meta: annotations, with no registration boilerplate.
• clojure.java.process (Clojure 1.12, no dependency) instead of a subprocess layer with two implementations.
• clojure.data.json used directly, no JSON abstraction.
• long / BigInt integer semantics, decided once.
• One test command, one CI job, one set of fixtures with one expected result.

What it costs

• No model-based testing of ClojureScript front ends.
• If that is ever wanted, it cannot be a port of this design — it would need explicit registration instead of scanning. What would carry over is the pure half: itf, replay and report consume a plain driver map, know nothing about metadata, and use no JVM interop. That separation is deliberate insurance, not a promise.

Consequences

• No .cljc files, no reader conditionals.
• JVM interop is allowed wherever it is the simplest answer, but the three pure namespaces should not need it, and a JVM call appearing in one of them is a review question.