Language Tour

This is a fast pass over the language.

type Result =
  | Ok of string
  | Error of string

let classify score =
  if score >= 10 then
    Ok "pass"
  else
    Error "fail"

let message =
  match classify 12 with
  | Ok text -> $"Result: {text}"
  | Error text -> $"Result: {text}"

print message

What this introduces:

• type for union declarations,
• if/else as an expression,
• match for exhaustive branching,
• string interpolation with $"...".

Next: continue into the language chapters for each feature in detail.