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Predicate Functions

Pure Boolean Validators for Runtime Checks​

NHB Toolbox provides predicate functions that deliver simple, efficient truth tests without type system side effects. These functions return boolean and work everywhere - from array filters to conditional logic.

Key Characteristics​

  • boolean Return Only - No type narrowing (use guards for that)
  • Zero Side Effects - Won't alter TypeScript's type inference
  • Lightweight - Optimized for performance-critical validation
  • Composable - Easily combine with &&/|| operators

Common Use Cases​

// 1. Array filtering
const validEmojis = emojiInputs.filter(isEmojiOnly);

// 2. Conditional logic
if (isEmojiOnly(value)) {
  saveToDatabase(value);
}

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