Language Tour¶

This tour is a living outline. It gives the website a useful structure now, while leaving room for the actual Catalyst syntax and semantics to become more precise.

Values¶

let answer = 42
let language = "Catalyst"
let ready = true

Functions¶

fn double(value: Int) -> Int {
  return value * 2
}

Branching¶

fn label(score: Int) -> String {
  if score >= 90 {
    return "excellent"
  }

  return "steady"
}

Data¶

type User {
  name: String
  reputation: Int
}

Errors¶

Catalyst should make failure visible at the point where it matters. Document the final error model here once it is stable.

Tests¶

test "double multiplies by two" {
  assert double(21) == 42
}

Packages¶

Package and module documentation belongs here once the package manager or module layout is finalized.