ral

A shell where data stays data.

Capture output without turning it back into source code.

value

A value is.

Strings, lists, records. Keep them, pass them, transform them.

command

A command does.

Work in the world. Capture its output, handle its failure, bound its authority.

say which world you mean

Traditional shells make text serve as data, command name, and source code. ral refuses that ambiguity. $ reads a value; ! runs a stored command. Once output has become a value, the shell never splits it, expands it, or executes it by surprise.

one task, two contracts

Fetch JSON from many URLs in parallel and keep every outcome. A string shell needs a text protocol between workers. In ral, each worker returns an ordinary value: ok or err, ready to write as one report.

bash

# invent a text protocol; parse it later
xargs -P8 -I{} sh -c '
  body=$(curl -fsSL "$1") &&
    printf "ok\t%s\t%s\n" "$1" "$body" ||
    printf "err\t%s\n" "$1"
' sh {} < urls.txt > manifest.tsv

ral

let urls = from-lines-list 'urls.txt'
let report = par { |u|
    try {
        let data = curl -fsSL $u | from-json
        return [url: $u, result: `ok $data]
    } { |e| return [url: $u, result: `err $e[message]] }
} $urls 8
to-json $report > 'manifest.json'

less shell to remember

ral's value language is small, typed, and purely functional. Bindings do not mutate. Lists and records are values, not encodings. Use map, filter, and fold instead of arranging a procession of text filters.

Parallel work needs no shared mutable state. Give par a block and a collection; its workers return values in input order. Decode bytes at an explicit boundary with from-json, from-lines, or another codec.

Commands remain visible as effects on the world. Their output can be captured, their failure handled, their interpretation replaced, and their authority narrowed with grant. An audit records the commands that ran and the permissions under which they ran.

get ral

curl -fsSL https://lambdabetaeta.github.io/ral/scripts/install.sh | sh

macOS arm64 ral-macos-arm64 allutils

Linux x86_64 ral-linux-x86_64 allutils

Linux arm64 ral-linux-arm64 allutils

Windows ral-windows.exe allutils

source: lambdabetaeta/ral .tar.gz .zip

one idea, followed through

The value–command split is call-by-push-value (Levy). Running an external command is an algebraic effect (Plotkin and Power): an operation whose interpretation can be handled, audited, or confined. The specification says what ral does; the rationale says why. ral runs Unix programs, but it is not POSIX shell — Bash scripts do not run unchanged.