///|
fn main {
  let before =
    #|contract Payment 1.0.0
    #|type Receipt closed
    #|field id string required
    #|field amount int required min=0
    #|field state enum:created|settled|refunded required
    #|end
  let after =
    #|contract Payment 1.1.0
    #|type Receipt closed
    #|field id string required minlen=8
    #|field amount int required min=1
    #|field state enum:created|settled required
    #|field memo string optional maxlen=120
    #|end
  match @evo.analyze_text(before, after, mode=@evo.Backward) {
    Ok(report) => println(report.to_markdown())
    Err(error) => println("Could not parse example: " + error.render())
  }
}