A Clojure compiler implemented on top of Chez Scheme https://jolt-lang.github.io/
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Yogthos 2de0543613 More library-compat fixes from porting the examples (markdown, malli)
Reader / loader:
- #?@ splicing reader conditionals now actually splice the matched collection's
  items into the enclosing sequence; the splice flag was read but ignored, so a
  binding vector like [a #?@(:clj [b (.foo b)])] lost its alignment.
- the file loader reads by position and skips a top-level form that reads as
  nothing (a :cljs-only #?, a #_ discard, a trailing comment) instead of
  treating it as EOF — which silently dropped the rest of a large .cljc file.
- jolt's reader feature set now includes :clj (was {:jolt :default}). jolt is a
  Clojure/JVM-compatible host that emulates clojure.lang.* and java.* interop,
  so it reads the :clj branch of a .cljc library, not :cljs. This also lets four
  more reader-conditional corpus cases pass (floor 2726 -> 2730).

Backend:
- munge-name escapes ' (prime) -> _PRIME_; a Clojure symbol like f' otherwise
  emitted a bare ' into Scheme, which is the quote reader macro and unbalanced
  the output.

Host shims:
- clojure.java.io/writer (pass through a StringWriter, file-back a path) and a
  readLine on the string reader, so line-seq over (io/reader …) works (markdown).

A better "unsupported destructuring pattern: <pat>" error message.
2026-06-22 02:25:11 -04:00
.github/workflows CI runs behavior gates; self-host fixpoint is dev-only (jolt-8479) 2026-06-21 15:46:40 -04:00
bench Delete the Janet host — Chez is the sole substrate 2026-06-21 11:29:03 -04:00
bin deps.edn resolution + a file loader + a project-aware CLI 2026-06-22 02:06:05 -04:00
docs spec: set! now supports deftype mutable fields 2026-06-22 01:19:21 -04:00
host/chez More library-compat fixes from porting the examples (markdown, malli) 2026-06-22 02:25:11 -04:00
img ci: run jpm bootstrap from inside the jpm checkout 2026-06-05 18:30:27 -04:00
jolt-core More library-compat fixes from porting the examples (markdown, malli) 2026-06-22 02:25:11 -04:00
spike/chez Delete the Janet host — Chez is the sole substrate 2026-06-21 11:29:03 -04:00
src/jolt Scrub dangling Janet references; drop dead Janet-coupled files 2026-06-21 12:01:04 -04:00
test mutable deftype fields: (set! field val) in a method 2026-06-22 01:19:03 -04:00
tools core: one alias store (jolt-ark); '.' classified as the special form it is 2026-06-10 18:37:19 -04:00
vendor SCI conformance gate (pure Chez) 2026-06-21 12:06:18 -04:00
.DS_Store Compiler research (#10) 2026-06-09 07:30:25 +08:00
.gitignore remove .calva from git 2026-06-08 19:31:26 -04:00
.gitmodules SCI conformance gate (pure Chez) 2026-06-21 12:06:18 -04:00
AGENTS.md Compiler research (#10) 2026-06-09 07:30:25 +08:00
CLAUDE.md Docs + CI for the Chez-only substrate 2026-06-21 11:34:48 -04:00
clojuredocs-export.edn records as shape-recs carrying a type tag (jolt-t34 R3) 2026-06-13 20:40:50 -04:00
clojuredocs-export.json records as shape-recs carrying a type tag (jolt-t34 R3) 2026-06-13 20:40:50 -04:00
foundational-runtime-handoff.md Scrub dangling Janet references; drop dead Janet-coupled files 2026-06-21 12:01:04 -04:00
LICENSE Initial commit: Jolt — Clojure interpreter on Janet 2026-06-01 16:48:56 -04:00
Makefile CI runs behavior gates; self-host fixpoint is dev-only (jolt-8479) 2026-06-21 15:46:40 -04:00
README.md SCI conformance gate (pure Chez) 2026-06-21 12:06:18 -04:00

Jolt

tests

A Clojure implementation on Chez Scheme. Jolt reads Clojure source, analyzes it to a host-neutral IR, emits Scheme, and runs it on Chez. The compiler is self-hosted: it is written in Clojure (jolt-core/) and compiles itself. It ships a Clojure-compatible standard library.

Requirements

Only Chez Scheme (the gate invokes it as chez). The conformance gate additionally uses Clojure on the JVM as an oracle, but running jolt does not.

Build

There is no build step. The bootstrap seed (host/chez/seed/{prelude,image}.ss) is checked in, so a fresh clone runs immediately:

git clone --recurse-submodules https://github.com/jolt-lang/jolt.git
cd jolt
bin/joltc -e '(+ 1 2)'        # => 3

After changing a compiler source — the reader (host/chez/reader.ss), the analyzer/IR/backend (jolt-core/jolt/*.clj), or the clojure.core overlay (jolt-core/clojure/core/*.clj) — re-mint the seed:

make remint                   # iterates host/chez/bootstrap.ss to a byte-fixpoint

Run

bin/joltc -e EXPR             # evaluate a Clojure expression and print the result
$ bin/joltc -e '(->> (range 10) (filter even?) (map (fn [x] (* x x))) (reduce +))'
120
$ bin/joltc -e '(/ 1 2)'
1/2

Architecture

A small Chez runtime (host/chez/*.ss: value model, persistent collections, seqs, vars/namespaces, host interop) hosts a portable Clojure overlay (jolt-core/): the reader/analyzer/IR/backend (jolt-core/jolt/) and clojure.core in dependency-ordered tiers (jolt-core/clojure/core/NN-*.clj). The stdlib namespaces (clojure.string/set/walk/edn/pprint/…) are portable Clojure under src/jolt/clojure/.

bin/joltc loads the checked-in seed and the spine, then compiles and evaluates on Chez (read → analyze → IR → emit → eval). host/chez/bootstrap.ss rebuilds that seed from source on pure Chez; the build is a self-hosting fixpoint (a rebuild reproduces the checked-in seed byte-for-byte).

Differences from Clojure

Jolt targets Clojure semantics but runs on Chez, not the JVM.

  • Host platform. No JVM and no Java interop — import, gen-class, proxy of Java classes, and java.* are unavailable. A class token resolves to a name; a small set of host classes is recognized for instance?.
  • Numbers. The full Scheme numeric tower, matching the JVM: exact integers and bignums, exact ratios ((/ 1 2)1/2), and flonum doubles. = is category-aware ((= 3 3.0)false); == is value-equality ((== 3 3.0)true). integer?/int? are exact integers, float?/double? are flonums, ratio? is an exact non-integer. No BigDecimal (decimal? is always false).
  • Concurrency. future/promise/agent/pmap run on real OS threads over a shared heap, matching JVM semantics (not isolated-heap snapshots). Atoms use a per-atom mutex with JVM-style CAS. clojure.core.async provides blocking channels and go/<!/>!/alts!/timeout.
  • Regex. Backed by irregex (vendored), PCRE/Java-style patterns.
  • Collections. Immutable persistent vectors (32-way tries), cons lists, and HAMT maps/sets. Hash-map/hash-set iteration order is unspecified — use sorted-map/sorted-set when order matters. Transients are real mutable scratch collections.

Supported and Clojure-compatible: lazy/infinite sequences, transducers, destructuring, multimethods with hierarchies, protocols/records (deftype/defrecord/reify/extend-protocol), metadata, namespaces, runtime eval/load-string/defmacro, and the reader (#(), #_, #?, tagged literals, #"…").

Test

make test                     # the full gate (no Janet)
make corpus                   # conformance corpus vs the JVM-sourced spec
make unit                     # host-specific unit cases
make selfhost                 # bootstrap fixpoint (rebuild == checked-in seed)
make smoke                    # bin/joltc CLI smoke
make sci                      # load borkdude/sci's source through joltc (compat stress)
make certify                  # JVM oracle (skips if clojure is absent)

The conformance corpus (test/chez/corpus.edn) is a host-neutral language spec whose expected values are sourced from reference JVM Clojure. See test/conformance/SPEC.md.

License

Eclipse Public License 1.0