slang v0.2.5

Build speed and stack safety since v0.2.4:

• Development builds: slangc --dev (or SLANG_DEV=1) compiles the generated C at -O0 without LTO, for edit-and-rerun loops such as zokor watch: a 21k-line service rebuilds in about 16 s instead of 73 s. Tasks start on a 32KB stack with a 16KB safepoint margin, and dev and release builds are cached apart. Not for deployment: the program uses about 1.6x the CPU.
• Frame guards are remembered between builds (~/.cache/slang/frames/, or $SLANG_CACHE/frames/), so a rebuild compiles the C once instead of two or three times (that 21k-line service: 225 s to 73 s).
• Generated codecs are frame-guarded: json.decode/json.encode, pg.rows_as and inspect of a wide struct (200+ fields) no longer overflow the task stack.
• macOS: slangc builds with -flto=thin. Xcode 15's linker dropped the frame report under full LTO, so no function was guarded there.
• Linux: functions gcc reports under a clone's name (.constprop, .isra, .part, .lto_priv) are guarded.
• GC: result, opt and struct values with GC roots carry explicit, zeroed padding, so stale padding words are no longer scanned as possible pointers and cannot keep dead objects alive.

Install

From a tarball (relocatable: unpack anywhere and run in place). Pick
the one for your platform below; each was unpacked outside the source tree
and used to build and run a new project before this release was published.

tar -xzf slang-0.2.5-darwin-arm64.tar.gz
./slang-0.2.5-darwin-arm64/bin/slangc --version     # slangc 0.2.5

From source:

git clone https://github.com/dolphlabs/slang && cd slang
git checkout v0.2.5
sudo make install          # PREFIX=/usr/local, or ~/.local

slangc new hello && cd hello && slangc main.sl --run

Upgrading a source install: run sudo make uninstall from the old
checkout first. make install overwrites the binary but never deletes
stale runtime files.

Requirements

slangc compiles to C, so every platform needs a C compiler (cc).

you import	you need
anything	a C compiler
net with TLS, crypto, httpc over https	OpenSSL (macOS: brew install openssl; Debian/Ubuntu: apt install libssl-dev)
sql	SQLite (Debian/Ubuntu: apt install libsqlite3-dev; ships with macOS)
compress, httpc	zlib (Debian/Ubuntu: apt install zlib1g-dev; ships with macOS)

The Linux tarballs are built on Ubuntu 24.04 and need glibc 2.39 or later;
on an older distribution, build from source.

SHA-256

509d074c15141bc05c139f79d8baf1c82ac6f0836dc4000530dd51b58917b37c  slang-0.2.5-darwin-arm64.tar.gz
8f64f64e5735233af053160510903579a7c2e6350eca0d0d6ccfd40b20974990  slang-0.2.5-darwin-x86_64.tar.gz
2d3e9751ad15429c921e4ff3adf7acc203c4e105e6238e26635954c577fb9b7f  slang-0.2.5-linux-aarch64.tar.gz
d7c3b8ecf63039e1c43aa12a3bce7505446a07074261007c6c47544d3dab1e8b  slang-0.2.5-linux-x86_64.tar.gz

slang v0.2.4

Process, file watching, standard library, HTTP/2 and runtime updates since v0.2.3:

• Processes: proc.spawn starts a child without a shell (optionally in its own process group with proc.SPAWN_GROUP, or with stdin on /dev/null with proc.SPAWN_NULL_STDIN); an empty environment list inherits the parent's. proc.wait waits for it with a deadline, parking the task on a pidfd (Linux) or kqueue (macOS) instead of blocking a worker, and proc.kill signals a child or its whole group.
• File watching: os.watch, os.watch_next and os.watch_close report batches of changed paths under a directory tree, with exclusions, through inotify (Linux) or FSEvents (macOS). os.mtime_ns gives nanosecond modification times.
• Standard library:
  • sort: in-place sorting and binary search.
  • crypto: Argon2id runs on dedicated KDF threads, and rsa_verify_sha256.
• HTTP/2: a multiplexed client, and responses with trailers. The client closes its transport only after its reader stops.
• Code generation: every opt and result is held by value; the current task is resolved once per function; loops with a numeric + stay on the leaf path. Loop GC roots stay current across iterations, and a chan_recv fill after a promoting wait is barriered.
• Scheduler: idle workers spin and poll the network while spinning, and the parked-task registry is sharded off the GC lock.
• Networking: reactor waiters are woken only through their own registration, and httpc applies the request deadline to connecting.
• Build: gcc's LTO pass no longer warns on every program built.

Install

From a tarball (relocatable: unpack anywhere and run in place). Pick
the one for your platform below; each was unpacked outside the source tree
and used to build and run a new project before this release was published.

tar -xzf slang-0.2.4-darwin-arm64.tar.gz
./slang-0.2.4-darwin-arm64/bin/slangc --version     # slangc 0.2.4

From source:

git clone https://github.com/dolphlabs/slang && cd slang
git checkout v0.2.4
sudo make install          # PREFIX=/usr/local, or ~/.local

slangc new hello && cd hello && slangc main.sl --run

Upgrading a source install: run sudo make uninstall from the old
checkout first. make install overwrites the binary but never deletes
stale runtime files.

Requirements

slangc compiles to C, so every platform needs a C compiler (cc).

you import	you need
anything	a C compiler
net with TLS, crypto, httpc over https	OpenSSL (macOS: brew install openssl; Debian/Ubuntu: apt install libssl-dev)
sql	SQLite (Debian/Ubuntu: apt install libsqlite3-dev; ships with macOS)
compress, httpc	zlib (Debian/Ubuntu: apt install zlib1g-dev; ships with macOS)

The Linux tarballs are built on Ubuntu 24.04 and need glibc 2.39 or later;
on an older distribution, build from source.

SHA-256

e348e1d957bae6bc9d01dd7e7a7b719328f7b76c31b547fed1a6464b641337c9  slang-0.2.4-darwin-arm64.tar.gz
405cd4899f75549fc7536ba4e54089e72a78f72735bf10d7b7ec63244ed480fe  slang-0.2.4-darwin-x86_64.tar.gz
7e4189bd223c915dfc792436355cc5a50b1dc98c08fb00b2f39566d446cd300b  slang-0.2.4-linux-aarch64.tar.gz
7de17b03e16db023a5ef03319136a7b6a5e4899d0b668e1233925635655071f1  slang-0.2.4-linux-x86_64.tar.gz

slang v0.2.3

Language, runtime, networking and package updates since v0.2.2:

• Packages: exclude keeps a package's non-runtime directories (examples, docs, benchmarks) out of the projects that depend on it, and importing an excluded directory is refused.
• Networking: link.tls_accept runs a TLS handshake on a link, and link.split splits a link into a reader and a writer. An idle worker now polls the network itself on Linux, so a ready connection runs without a thread handoff; SLANG_NO_WORKER_POLL=1 turns this off. The reactor makes one epoll_ctl call per wait instead of two, and it no longer scans every waiter on every wakeup.
• Scheduler: a spawn followed straight by join_wait runs in place on the spawner, with a recovery point that turns a panic into the join's error. The worker pool is sized to a cgroup CPU quota.
• Garbage collection: minor collections skip idle queued tasks as well as parked ones. A value sent through an old channel is no longer promoted on every send.
• HTTP: Date is sent on every response, and 204 and 304 responses carry no body or length. write_head frames a HEAD answer. Methods that are not tokens are refused. CR and LF in header fields are written as spaces. Extra header lines are written without copying.
• PostgreSQL: pg.rows_as decodes typed rows directly, without intermediate JSON text, and timez.Time values bind as times.
• Standard library:
  • timez: calendar time, formats, time zones and cron.
  • JSON: timez.Time encodes as an RFC 3339 string.
  • fs.realpath and fs.fstat.
  • Bounded Argon2id in crypto.
  • crypto.rand reads the OS random source (getrandom, arc4random_buf) instead of OpenSSL under a global lock.
• Compiler fixes:
  • escape analysis for values sent from a select arm;
  • liveness through local function values and method receivers;
  • roots for spawn arguments;
  • wrapping signed division by -1;
  • extern functions under their own C names;
  • generated lines longer than 16 KB.
• Tooling: slangc test loads pins from the package under test, and crash reports print the pc as an offset into the image.

Install

From a tarball (relocatable: unpack anywhere and run in place). Pick
the one for your platform below; each was unpacked outside the source tree
and used to build and run a new project before this release was published.

tar -xzf slang-0.2.3-darwin-arm64.tar.gz
./slang-0.2.3-darwin-arm64/bin/slangc --version     # slangc 0.2.3

From source:

git clone https://github.com/dolphlabs/slang && cd slang
git checkout v0.2.3
sudo make install          # PREFIX=/usr/local, or ~/.local

slangc new hello && cd hello && slangc main.sl --run

Upgrading a source install: run sudo make uninstall from the old
checkout first. make install overwrites the binary but never deletes
stale runtime files.

Requirements

slangc compiles to C, so every platform needs a C compiler (cc).

you import	you need
anything	a C compiler
net with TLS, crypto, httpc over https	OpenSSL (macOS: brew install openssl; Debian/Ubuntu: apt install libssl-dev)
sql	SQLite (Debian/Ubuntu: apt install libsqlite3-dev; ships with macOS)
compress, httpc	zlib (Debian/Ubuntu: apt install zlib1g-dev; ships with macOS)

The Linux tarballs are built on Ubuntu 24.04 and need glibc 2.39 or later;
on an older distribution, build from source.

SHA-256

cad234a651435bdd9a52d119e0283131abd613a76d9b06552acc995cf34f10c7  slang-0.2.3-darwin-arm64.tar.gz
ed36209f7611f6d6ede5dcbed3e4c3015adb2adf5281f5fec498a464997bf112  slang-0.2.3-darwin-x86_64.tar.gz
efe9833374009960fb1daefa49d823c6982f1af186b826b655d31cbfbde6d140  slang-0.2.3-linux-aarch64.tar.gz
8ce2bbb537225f0562f83b544933e591a754a983f4f88e778e887e60b966e5d4  slang-0.2.3-linux-x86_64.tar.gz

slang v0.2.2

Runtime, database, and networking updates:

• Improve generational garbage collection with page-ordered sweeping, parallel sweep and marking, and less work for pointer-free containers and long-idle tasks. Fix tracing of value structs and opt/result payloads.
• Reduce PostgreSQL overhead with reusable query buffers, binary result decoding, FIFO pool waiters, and per-connection prepared statements.
• Bound Redis replies and improve pool waiter wakeups.
• Add bounded, deadline-aware DNS SRV/TXT lookup APIs for DNS seed-list clients such as MongoDB Atlas.
• Add little-endian binary64 conversion helpers and improve compiler diagnostics and fatal-signal reporting.

Install

From a tarball (relocatable: unpack anywhere and run in place). Pick
the one for your platform below; each was unpacked outside the source tree
and used to build and run a new project before this release was published.

tar -xzf slang-0.2.2-darwin-arm64.tar.gz
./slang-0.2.2-darwin-arm64/bin/slangc --version     # slangc 0.2.2

From source:

git clone https://github.com/dolphlabs/slang && cd slang
git checkout v0.2.2
sudo make install          # PREFIX=/usr/local, or ~/.local

slangc new hello && cd hello && slangc main.sl --run

Upgrading a source install: run sudo make uninstall from the old
checkout first. make install overwrites the binary but never deletes
stale runtime files.

Requirements

slangc compiles to C, so every platform needs a C compiler (cc).

you import	you need
anything	a C compiler
net with TLS, crypto, httpc over https	OpenSSL (macOS: brew install openssl; Debian/Ubuntu: apt install libssl-dev)
sql	SQLite (Debian/Ubuntu: apt install libsqlite3-dev; ships with macOS)
compress, httpc	zlib (Debian/Ubuntu: apt install zlib1g-dev; ships with macOS)

The Linux tarballs are built on Ubuntu 24.04 and need glibc 2.39 or later;
on an older distribution, build from source.

SHA-256

fdb20eb7ab35aad071e244d61596dea204e180f290f24e94dca19feaaf7231f9  slang-0.2.2-darwin-arm64.tar.gz
62ee922f85288e72dc3dd49eede2433515342f01ab9777dd3815392d452e0e6d  slang-0.2.2-darwin-x86_64.tar.gz
df97ac0d523d133b5ba59fecbf42813dd89cfa703834cd8f8590b72ddbe56fdc  slang-0.2.2-linux-aarch64.tar.gz
b4525b08ff69cda6c817e69186359ecb6d4d353b223512d0a0a4b1d887f28d66  slang-0.2.2-linux-x86_64.tar.gz

slang v0.2.0

slang is a statically typed language built primarily for server-side and network programming, compiling to C. This release adds an HTTP client, compression and encoding, and fixes a runtime memory-safety bug.

Install

From source:

git clone https://github.com/dolphlabs/slang && cd slang
git checkout v0.2.0
sudo make install          # PREFIX=/usr/local, or ~/.local

slangc new hello && cd hello && slangc main.sl --run

Upgrading: run sudo make uninstall from your old checkout first. make install overwrites the binary, but it copies runtime files over the old ones and never deletes stale ones.

From the tarball (macOS x86_64, relocatable, runs in place):

tar -xzf slang-0.2.0-darwin-x86_64.tar.gz
./slang-0.2.0-darwin-x86_64/bin/slangc --version     # slangc 0.2.0

sha256 52994a0d4980de3d6b09ee6cb94e9e684ac955ef4cabc2c4850dbe709408dc24

Requirements

The v0.1.0 notes said building "needs nothing but a C compiler". That is true for the core language, but not for every package:

you import	you need
anything	a C compiler
net with TLS, crypto, httpc over https	OpenSSL headers and pkg-config on your PATH
sql	SQLite (-lsqlite3, ships with macOS)
compress, httpc	zlib (ships with macOS)

On macOS, OpenSSL comes from Homebrew (brew install openssl pkg-config). If an https program fails with 'openssl/err.h' file not found, pkg-config isn't on your PATH. The tarball was verified in an otherwise empty environment with only Homebrew's bin on PATH.

What's new

Packages

encoding	hex, base64, base64url, percent-encoding, query strings
compress	gzip, zlib and raw DEFLATE. Decompression requires an output limit: a 64 MB gzip bomb is refused at 3.9 MB RSS
httpc	HTTP/1.1 client over http and https. Certificates always verified, credentials dropped on cross-origin redirects, every server-controlled buffer bounded

httpc.Client

• Connection pooling. Idle connections are probed before reuse (new net.idle_alive). A dropped request is retried only if it's idempotent, never a POST. The pool key includes the CA bundle.
• Transparent gzip/deflate decoding. Skipped if you set Accept-Encoding yourself.
• Cookie jar, off by default. A server's shared client would otherwise mix users' sessions. RFC 6265 with 6265bis Secure rules.

Language

• pub fn inside impl now parses. Before this, no method could be called from outside its own package, and the compiler's error told you to add the pub it then rejected.
• == and != work between two bools.

The fix worth calling out

Stack relocation left compiler-hoisted stack addresses dangling. When a task's stack grows, it is copied and the old one unmapped. At -O2, clang can keep an address from the old stack in a register across that call. A spawned task doing TLS I/O inside a helper, which is the normal shape of a TLS server, crashed 3/3. Before guard-paged stacks (v0.1.0), the same writes went silently into freed heap memory. After the fix: 5/5 clean, and 3/3 crashes return with it disabled.

Known open

• ~5% SIGBUS under amplified preemption. Still open, and not related to the fix above: that workload never grows a stack.
• No public-suffix list for cookies. Domain=co.uk from a.example.co.uk is accepted.
• A method can't share a name with a function in its package. This is why httpc uses client_get(c, …) rather than c.get(…).
• The stack-relocation regression test is compiler-sensitive, and says so. A clang upgrade could make it pass against a regression.

Only a macOS x86_64 binary is attached, because that is the only platform this release was built and verified on.

Full changes: #115 – #128. Suite: 176 passing.

slang v0.1.0

First tagged release. A statically typed language built primarily for server-side and network programming, compiling to C.

Install

From source (any platform with a C compiler):

git clone https://github.com/dolphlabs/slang && cd slang
sudo make install          # PREFIX=/usr/local, or ~/.local

slangc new hello
cd hello
slangc main.sl --run       # hello from hello

From the tarball (macOS x86_64) — relocatable, run it in place:

tar -xzf slang-0.1.0-darwin-x86_64.tar.gz
./slang-0.1.0-darwin-x86_64/bin/slangc --version

sha256 53027950307dc59b7eaf0450328218f5725481f737f7901b080e297eb7032969

Only a macOS x86_64 binary is attached, because that is the only platform this release was built and verified on. Building from source is the supported path everywhere else and needs nothing but a C compiler.

What's in it

Concurrency	M:N green tasks, chan[T], select, mutex, join
Functions	function values — deliberately no closures, nothing is captured
Errors	opt / result / fault, with err_of binding the error so it can be logged
Packages	time net json proc fs os log crypto sql regex strings, plus http, http2, byteutil in source
Tooling	make install, slangc new, slangc get, --version
Docs	a site generated from the repository itself — www/

Two fixes worth calling out

Both were live bugs, each with measured before/after evidence rather than a claim:

Vector registers across preemption. The async trampoline saved only the low 128 bits of each vector register, so an interrupted AVX2 memcpy lost 16 bytes whenever something executed vzeroupper while the task was switched out. 10/30 runs corrupted before, 0/30 after.

Guard-paged task stacks. Stacks were plain malloc blocks, so overflow silently overwrote the next heap block — routinely another task's stack. With a PROT_NONE page under each, the first thing that faulted was OpenSSL reaching dlopen → dyld, which had been overflowing on every crypto and TLS program since those packages landed. RSS went down (49MB vs 54–58MB at 2000 tasks) because mapped pages fault in lazily.

Known open

Recorded rather than hidden — todo.md carries the detail:

• A ~5% SIGBUS under amplified preemption, not observed at stock settings. Three explanations have been tested and eliminated; the entry names them so nobody re-runs them, and suggests a next step.
• HTTP throughput declines from 16.3k rps at c=10 to 10.9k at c=500. Not characterised — the load generator may be the limit, and that is stated instead of guessed.

Verification

Full suite 165 passing, generated C warning-free. make install verified from a clean prefix under env -i with only the install prefix on PATH; the tarball verified unpacked at an unrelated path.

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Built and maintained by Dolphlabs (Dolph Tech Limited).