Concurrent scoring

# title: Concurrent scoring
# category: Vibescript Showcase
# difficulty: Showcase
# summary: Fan a list of records through one scoring function with Tasks.map and collect ordered results concurrently.
# description: Tasks.map runs the same named function across every input concurrently, bounds the fanout with max:, and preserves input order in the result. This is the idiomatic way to parallelize independent per-record work in Vibescript 0.40.
# tags: concurrency, tasks, structured-concurrency, fanout
# featured: true
# feature_rank: 0
# vibe: 0.4

def score_user(user)
  user[:score] * user[:weight]
end

def score_users(users)
  Tasks.map(users, max: 4, with: :score_user)
end

def run
  users = [
    { id: "u1", score: 10, weight: 3 },
    { id: "u2", score: 7, weight: 5 },
    { id: "u3", score: 9, weight: 2 },
    { id: "u4", score: 4, weight: 8 }
  ]

  scores = score_users(users)

  {
    scores: scores,
    total: scores.sum
  }
end