A tour in five minutes

Brackets each have one job:

Bracket	Job
[ ]	sets and lists: permissions, lists, paths
{ }	blocks of code and records; {name} inside a string interpolates
( )	calls and grouping; the condition of if, for, match
< >	type parameters only, as in Secret<String>

needs [ read [./src], run ["npm test"] ]      // 1. the file starts with needs

let name = "world"                             // 2. let is fixed, mut changes
mut count = 0
let msg = "hello {name}"                       // {} interpolates
let files = [./a.ts, ./b.ts]                   // [] is a list; paths are bare
let cfg = { port: 8080, host: "x" }            // {} is a record

let t = run("npm test")?                       // 3. calls; ? passes a failure up
let n = read(./count.txt) or { "0" }           // or { } handles it here

if (t.failed) { log("failing") } else { log("ok") }
for (f in files) { log(f) }

let token: Secret<String> = env("TOKEN")       // 4. a secret can be used, never printed

Five things to remember:

1. The file starts with needs [ ... ].
2. let is fixed, mut is changeable.
3. Paths are written bare: ./src.
4. Failure is a value: ? passes it up, or { } handles it.
5. A secret can be used but never printed.

Statements end at the newline: no semicolons. Comments start with //.