Gates - Conditional Execution

examples/06-gates.halo policies

Skip pipeline stages with |? (condition) Condition uses variables or context from previous stages as name stores a stage's result at context.data.name

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// ============================================================
// STEP 6: Gates - Conditional Execution
// Learn: Skip pipeline stages with `|? (condition)`
// Condition uses variables or context from previous stages
// `as name` stores a stage's result at context.data.name
// ============================================================

policy NoProfanity : Block(Profanity)
policy ShortOnly : MaxWords(50)

agent Greeter [gemini-3-1-pro, temp: 0.7]
  requires NoProfanity, ShortOnly

pipeline ConditionalHello(name: String, lang: String) -> Result:
  name
    |> Greeter.prompt("Write a warm, 1-sentence greeting for {{name}}.") as greeting
    // Gate: Only translate if target language is not English
    |? (lang != "en")
    |> Greeter.prompt("Translate this greeting into the language with code {{lang}}:", context.data.greeting)
    |> System.Print()