Writing Idiomatic Dart

Contents

• Variables and State Management
• Functions and Closures
• Records and Pattern Matching
• Generics and Type Safety
• Workflow: Refactoring to Idiomatic Dart
• Examples

Variables and State Management

Manage state and variable declarations using strict mutability and type inference rules.

• Prefer var: Use var for local variables when the assigned type is obvious (e.g., var name = 'Bob';). Use explicit types when the type is not immediately clear from the initializer.
• Enforce Immutability: Use final for variables that should not be reassigned after initialization. Use const for compile-time constants and to create canonicalized, immutable object instances.
• Leverage late: Use the late modifier to defer initialization of non-nullable variables until their first use, especially for expensive computations or when initialization requires access to this.
• Implement Wildcards: Use the wildcard variable _ (requires Dart 3.7+) to discard unused values in local declarations, closures, or pattern matching without triggering unused variable warnings.

Functions and Closures

Structure functions for maximum composability and minimal boilerplate.