Lea Language

Quick Start

let numbers = [1, 2, 3, 4, 5]

let result = numbers
  /> filter((x) -> x > 2)
  /> map((x) -> x * x)
  /> reduce(0, (acc, x) -> acc + x)

result /> print

Core Principles

• Pipes:

  value /> fn

  passes value as first arg; use

  input

  placeholder to control position
• Functions:

  let double = (x) -> x * 2

  (no fn keyword)
• Multi-statement bodies: Indentation-based or brace-delimited

  { }

• Decorators: Trailing

  #log #memo #time #retry(3)

  etc. after function body
• Bindings:

  let x = 10

  immutable,

  maybe x = 0

  mutable
• Records:

  { name: "Max", age: 99 }

  with member access

  record.field

• Contexts:

  context Name = default

  +

  provide Name value

  +

  @Name

  attachments

Builtins

• Math:

  sqrt

  ,

  abs

  ,

  floor

  ,

  ceil

  ,

  round

  ,

  min

  ,

  max

• Lists:

  length

  ,

  head

  ,

  tail

  ,

  push

  ,

  concat

  ,

  map

  ,

  filter

  ,

  reduce

  ,

  range

• IO:

  print

  (returns first arg for chaining)
• Async:

  delay(ms)

  — promise that resolves after ms

Running

npm run repl            # Interactive REPL
npm run lea file.lea    # Run a file

Reference Files

• references/syntax.md - Full syntax reference
• references/architecture.md - Interpreter internals