Effect.ts: Absence as First-Class

Philosophy • Lesson 46 of 51

46. The Mental Model Shift

Stop thinking "async". Start thinking "absent".

Code Example
// OLD MENTAL MODEL: "Async/Await"
// "This operation takes time"
async function getUser() {
  const data = await fetchUser();
  return data;
}

// NEW MENTAL MODEL: "Absence Resolution"
// "This data doesn't exist yet, here's how to get it"
const getUser = Effect.gen(function* () {
  const data = yield* fetchUser;
  //           ^^^^^^
  //           Resolving absence
  return data;
});

// The shift:
// await = "wait for async"
// yield* = "resolve this absence"
Interactive Example
const output: string[] = [];
output.push(' Mental model shift:');
output.push('');
output.push('BEFORE:');
output.push('  "This operation is async"');
output.push('  → Focus on TIME');
output.push('');
output.push('AFTER:');
output.push('  "This data doesn't exist yet"');
output.push('  → Focus on ABSENCE');
output.push('');
output.push('Async ≠ slow');
output.push('Async = absent data');
output.push('');
output.push(' Type the absence!');
return output.join('
');
Explanation

The paradigm shift in one diagram:

TRADITIONAL THINKING:
"Async" → Time delay → Await → Value

ABSENCE-FIRST THINKING:
"Value doesn't exist" → Description of HOW → Execute → Value

Key insights:

  • Async isn't about TIME, it's about ABSENCE
  • await isn't waiting, it's RESOLVING
  • Promises aren't delayed values, they're ABSENT values
  • Effect makes the absence explicit and typed

Stop thinking:

  • "This is slow" → "This is absent"
  • "This takes time" → "This doesn't exist yet"
  • "This is async" → "This requires resolution"

Absence-first thinking: it changes everything!

Part 46 of 51 in the Effect.ts Absence Modeling series

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