017a1bc8c4
Re-port the SCI compatibility stress test to joltc: host/chez/run-sci.ss loads borkdude/sci's own source (vendor/sci, re-vendored) through the spine and requires its forms to compile+eval. Floor-gated at 160/218 forms (the tail is genuine host gaps — set! on vars, some macro/def shapes); raise as they close. Wired into 'make test' (skips if the submodule isn't checked out). jolt-cf1q.6
109 lines
4.6 KiB
Markdown
109 lines
4.6 KiB
Markdown
# Jolt
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[](https://github.com/jolt-lang/jolt/actions/workflows/tests.yml)
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A Clojure implementation on [Chez Scheme](https://cisco.github.io/ChezScheme/).
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Jolt reads Clojure source, analyzes it to a host-neutral IR, emits Scheme, and
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runs it on Chez. The compiler is self-hosted: it is written in Clojure
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(`jolt-core/`) and compiles itself. It ships a Clojure-compatible standard library.
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## Requirements
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Only [Chez Scheme](https://cisco.github.io/ChezScheme/) (the gate invokes it as
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`chez`). The conformance gate additionally uses Clojure on the JVM as an oracle,
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but running jolt does not.
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## Build
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There is no build step. The bootstrap seed (`host/chez/seed/{prelude,image}.ss`)
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is checked in, so a fresh clone runs immediately:
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```bash
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git clone --recurse-submodules https://github.com/jolt-lang/jolt.git
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cd jolt
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bin/joltc -e '(+ 1 2)' # => 3
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```
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After changing a compiler source — the reader (`host/chez/reader.ss`), the
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analyzer/IR/backend (`jolt-core/jolt/*.clj`), or the `clojure.core` overlay
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(`jolt-core/clojure/core/*.clj`) — re-mint the seed:
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```bash
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make remint # iterates host/chez/bootstrap.ss to a byte-fixpoint
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```
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## Run
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```bash
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bin/joltc -e EXPR # evaluate a Clojure expression and print the result
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```
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```bash
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$ bin/joltc -e '(->> (range 10) (filter even?) (map (fn [x] (* x x))) (reduce +))'
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120
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$ bin/joltc -e '(/ 1 2)'
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1/2
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```
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## Architecture
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A small Chez runtime (`host/chez/*.ss`: value model, persistent collections, seqs,
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vars/namespaces, host interop) hosts a portable Clojure overlay (`jolt-core/`): the
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reader/analyzer/IR/backend (`jolt-core/jolt/`) and `clojure.core` in
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dependency-ordered tiers (`jolt-core/clojure/core/NN-*.clj`). The stdlib namespaces
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(`clojure.string`/`set`/`walk`/`edn`/`pprint`/…) are portable Clojure under
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`src/jolt/clojure/`.
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`bin/joltc` loads the checked-in seed and the spine, then compiles and evaluates on
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Chez (read → analyze → IR → emit → eval). `host/chez/bootstrap.ss` rebuilds that
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seed from source on pure Chez; the build is a self-hosting fixpoint (a rebuild
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reproduces the checked-in seed byte-for-byte).
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## Differences from Clojure
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Jolt targets Clojure semantics but runs on Chez, not the JVM.
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- **Host platform.** No JVM and no Java interop — `import`, `gen-class`, `proxy` of
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Java classes, and `java.*` are unavailable. A class token resolves to a name; a
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small set of host classes is recognized for `instance?`.
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- **Numbers.** The full Scheme numeric tower, matching the JVM: exact integers and
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bignums, exact ratios (`(/ 1 2)` ⇒ `1/2`), and flonum doubles. `=` is
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category-aware (`(= 3 3.0)` ⇒ `false`); `==` is value-equality (`(== 3 3.0)` ⇒
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`true`). `integer?`/`int?` are exact integers, `float?`/`double?` are flonums,
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`ratio?` is an exact non-integer. No `BigDecimal` (`decimal?` is always false).
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- **Concurrency.** `future`/`promise`/`agent`/`pmap` run on real OS threads over a
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**shared heap**, matching JVM semantics (not isolated-heap snapshots). Atoms use a
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per-atom mutex with JVM-style CAS. `clojure.core.async` provides blocking channels
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and `go`/`<!`/`>!`/`alts!`/`timeout`.
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- **Regex.** Backed by [irregex](https://github.com/ashinn/irregex) (vendored),
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PCRE/Java-style patterns.
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- **Collections.** Immutable persistent vectors (32-way tries), cons lists, and HAMT
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maps/sets. Hash-map/hash-set iteration order is unspecified — use
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`sorted-map`/`sorted-set` when order matters. Transients are real mutable scratch
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collections.
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Supported and Clojure-compatible: lazy/infinite sequences, transducers,
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destructuring, multimethods with hierarchies, protocols/records
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(`deftype`/`defrecord`/`reify`/`extend-protocol`), metadata, namespaces, runtime
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`eval`/`load-string`/`defmacro`, and the reader (`#()`, `#_`, `#?`, tagged literals,
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`#"…"`).
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## Test
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```bash
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make test # the full gate (no Janet)
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make corpus # conformance corpus vs the JVM-sourced spec
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make unit # host-specific unit cases
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make selfhost # bootstrap fixpoint (rebuild == checked-in seed)
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make smoke # bin/joltc CLI smoke
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make sci # load borkdude/sci's source through joltc (compat stress)
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make certify # JVM oracle (skips if clojure is absent)
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```
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The conformance corpus (`test/chez/corpus.edn`) is a host-neutral language spec
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whose expected values are sourced from reference JVM Clojure. See
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[test/conformance/SPEC.md](test/conformance/SPEC.md).
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## License
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[Eclipse Public License 1.0](https://opensource.org/licenses/EPL-1.0)
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