pattern-matching
Pattern Matching in Effect
Overview
Pattern matching replaces complex control flow in Effect code. Simple if/else (no nesting, no else if) is allowed, but else if chains, nested conditionals, and ternary operators must use pattern matching.
Effect's Match module provides:
- Exhaustive matching - Compiler ensures all cases handled
- Type narrowing - Automatic type inference in each branch
- Composable matchers - Build complex patterns from simple ones
- Predicate support - Match on conditions, not just values
What to Use Instead of Imperative Code
| Imperative Pattern | Effect Replacement |
|---|---|
Simple if/else (no nesting) |
Allowed as-is |
else if chains |
Match.value + Match.when |
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