Bn Php Laravel Package

Getting Started

Install via Composer: composer require simplito/bn-php. This library provides arbitrary-precision integer arithmetic (BigNumber class) and is designed to be interoperable with the popular JavaScript bn.js library—especially useful in cross-language or blockchain-related projects (e.g., Ethereum). Start by importing the namespace: use Simplito\BigNum\BigNum;. A minimal usage example:

$bn = BigNum::from(123456789);
$sum = $bn->add(BigNum::from('987654321'));
echo $sum->toString(); // "1111111110"

For base conversion (e.g., hex to BN), use BigNum::from($hexString, 16).

Implementation Patterns

• Blockchain token handling: Parse hex-encoded values from blockchain APIs (e.g., Ethereum balances in wei) using BigNum::from($hex, 16) and format output with $bn->toJSON() or $bn->toString(16).
• Interoperable crypto primitives: When integrating with JS frontends or Web3 tools, ensure BN→BN compatibility by leveraging BigNum::from('0x123', 16) on both sides.
• Efficient arithmetic: Use chained methods for gas optimizations:
  $fee = BigNum::from($gasLimit)->mul($gasPrice)->div(BigNum::from(1000000000));
• Validation & comparison: Use $bn->gt($other), $bn->lt(), or $bn->eq() for conditional logic instead of casting to strings/numbers.

Gotchas and Tips

• Hex input convention: Unlike bn.js, this library expects lowercase hex prefixes (0x) but does not require them—you can pass raw hex (e.g., '1a2b'). Omit 0x unless specified in from($str, $base) (where base=16 handles both).
• Negative numbers: Not natively supported. Workaround: store sign separately or use two’s complement manually—common for blockchain data.
• PHP integer limits: Avoid direct PHP arithmetic on BN values; always use BN methods to prevent overflow or precision loss.
• Performance: BN operations are expensive—cache results in memory when computing repeatedly (e.g., in loops or recurring calculations).
• Missing methods: Not all bn.js features are implemented (e.g., modPow, extended Euclidean algorithm). Check BigNum source methods—contribution opportunities exist.
• Testing tip: Use PHPUnit’s assertEquals() with toString() because object comparison fails even for identical values.