kw else

ClusterClause = "seeds" Expr | "port" IntLit | "trace_sample" FloatLit | "auth" Block | "defaults" "{" { Ident Expr } "}"
            | "role" Ident "{" RoleClause { ( ";" | NL ) RoleClause } "}"
            | "assign" "by" Expr { "else" Expr } ;

If          = "if" ( Expr | "let" Pattern "=" Expr ) Block [ "else" ( If | Block ) ] ;

SelArm      = ( "recv" Pattern "from" Expr | "send" Expr "to" Expr | "after" Expr | "else" ) "=>" Expr ;

let (tx, rx) = chan<Job>(cap: JOB_QUEUE)

select {
  recv job from rx  => process(job)
  send r to results => sent += 1
  after IDLE_TIMEOUT => log.info("idle")
  else              => tick()          // non-blocking variant
}

let kind = if n < 0 { "neg" } else if n == 0 { "zero" } else { "pos" }
if let User{ role: .Admin, name, .. } = u { greet(name) }
if x is Receipt { save(x) }          // x is narrowed to Receipt