peachq

An open-source implementation of the q programming language, MIT-licensed, built on rayforce - a pure C17, zero-dependency columnar engine by Anton Kundenko (credits below).

It aims for close behavioural compatibility with q, measured the only way that means anything: q-observable behaviour - parse display, type shorts, error text, and console formatting.

Website · Try online · Download · Compatibility · Roadmap

Important

PeachQ is useful but still early. It is not yet a drop-in replacement for production kdb+/q systems. Check the compatibility dashboard and known limitations before evaluating it for a workload.

A session

Real output from ./q:

q)kt:([s:`ibm`msft] px:187.5 402.1)     / keyed table literal
q)kt[`msft]
px| 402.1
q)select avg px by s from ([]s:`a`b`a`b;px:1.5 2.5 3.5 4.5)
s| px
-| ---
a| 2.5
b| 3.5
q)2024.01.15D10:30:00 + 0D01:15:00      / timestamp + timespan
2024.01.15D11:45:00.000000000
q){x*x} each til 5                       / lambdas, adverbs
0 1 4 9 16
q)count each group `ibm`msft`ibm
ibm | 2
msft| 1
q)(+/)1 2 3 4                            / derived verbs are first-class values
10
q)parse "2+3"                            / kdb-identical parse display
(+;2;3)
q)"D"$"2024.01.15"
2024.01.15
q)-8!42                                  / kdb wire serialization
0x0100000011000000f92a00000000000000
q)meta ([]a:1 2;b:`x`y)
c| t f a
-| -----
a| j
b| s

Download & run

Prebuilt q binaries are on the latest release.

Linux (static, runs on any distro):

curl -fsSL https://github.com/peachq-org/peachq/releases/latest/download/peachq-linux-x86_64.tar.gz | tar xz
./q

macOS (Apple Silicon):

curl -fsSL -o peachq.tar.gz https://github.com/peachq-org/peachq/releases/latest/download/peachq-macos-arm64.tar.gz
tar xzf peachq.tar.gz
xattr -d com.apple.quarantine ./q   # clear the macOS Gatekeeper quarantine
./q

Windows: download peachq-windows-x86_64.zip from the latest release, extract it, and run q.exe.

Build from source

make            # optimized build: ./q
make rayforce   # optional: the underlying rayfall engine REPL
make debug      # unoptimized + sanitizers
./q             # q REPL;  printf '2+3\n' | ./q  for piped mode
./q -p 5000     # kdb-wire server - point qStudio or a kdb client at it

What works today

• Datatypes: all q atom/vector types including the full temporal family (date, time, timestamp, timespan, month, minute, second, datetime), byte, guid. Type tags are kdb's numbers; type and meta report kdb's chars.
• Core language: verbs and adverbs (/ \ ' \: /:), lambdas {x+y}, projections, composition, derived verbs as first-class 104h values, dicts, tables, keyed tables (literal, !/0!, xkey, row lookup, upsert).
• qSQL: select (where / by / aggregates) and functional ?/! core; exec/update/delete partial.
• IPC: speaks the kdb wire - -8!/-9!, ./q -p PORT server, hopen/hclose client; qStudio connects and runs queries.
• Platforms: Linux, macOS, Windows; browser via WebAssembly.

How it's built

1. No q interpreter. The parser reads q and builds engine ray_t trees directly with registry function values embedded at verb heads. One lowering pass turns q-only shapes into pure array applications; the engine's evaluator/DAG does all execution.
2. One manifest for all verbs. Every q verb is a single row in the op manifest - lexer and runtime registry both derive from it.
3. q datatypes are native. Types the engine lacked (the temporal family, byte, guid) were added to its own type system, and its type tags ARE kdb's type numbers.

Credits: standing on rayforce

peachq exists because of rayforce and one person in particular: Anton Kundenko. Anton built the columnar engine at the heart of this project - the dataframe core, the vector kernels, the DAG evaluator - and it is genuinely a work of art. Fast, lean, zero-dependency C that makes q's whole model possible. peachq is a q language layer riding on top of that engine; the hard, beautiful part underneath is his.

Huge thanks to Anton, and to the rest of the rayforce crew - Serhii Savchuk, Hetoku, and everyone whose commits shaped the engine. The bulk of this codebase is theirs, and the commit history preserves every one of them verbatim (git shortlog -sne).

The q layer on top - parser, q datatypes, lowering pass, registry, formatter, and kdb-wire IPC - was written by Ryan Hamilton. Full attribution: AUTHORS.

Contributing

This repo is a read-only release mirror of a private development repo, so pull requests here can't be merged - but bug reports and ideas are very welcome via Issues. See CONTRIBUTING.md.

License

MIT. Portions Apache-2.0 and MIT - see NOTICE and AUTHORS.

Trademarks

q and kdb+ are trademarks of KX Systems, Inc. peachq is an independent, community project and is not affiliated with, endorsed by, or sponsored by KX Systems. Any references to kdb+/q describe interoperability and behavioural compatibility only.