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🔢 Decimals Converter

Introduction​

The Decimals Converter library is designed to simplify the conversion of numbers that use token decimals from one precision to another.

Users are encouraged to use from18Safe() instead of from18() by default to avoid potentially small amounts of exploits.

Functions​

To use the DecimalsConverter library, you need to import it.

import "@solarity/solidity-lib/libs/utils/DecimalsConverter.sol";

And optionally bind it to the type with the using statement.

using DecimalsConverter for *;

decimals​

function decimals(address token_) internal view returns (uint8);

Description​

This function returns the decimals of ERC20 token_. You may use this function for bytecode optimization.

Time complexity​

Constant.

Example​

address token_ = address(0x...);

token_.decimals(); // 18

to18​

function to18(uint256 amount_, address token_) internal view returns (uint256);

Description​

This function brings the given amount_ to 18 decimals of precision based on the token_ decimals.

Time complexity​

Constant.

Example​

address token_18_ = address(0x...);
address token_16_ = address(0x...);
address token_20_ = address(0x...);
address token_21_ = address(0x...);

uint256 amount_ = 100;

amount_.to18(token_18_); // 100
amount_.to18(token_16_); // 10000
amount_.to18(token_20_); // 1
amount_.to18(token_21_); // 0

to18​

function to18(
    uint256 amount_, 
    uint256 baseDecimals_
) internal pure returns (uint256);

Description​

This function brings the given amount_ to 18 decimals of baseDecimals_.

Time complexity​

Constant.

Example​

uint256 amount_ = 100;

amount_.to18(18); // 100
amount_.to18(16); // 10000
amount_.to18(20); // 1
amount_.to18(21); // 0

to18Safe​

function to18Safe(
    uint256 amount_, 
    address token_
) internal view returns (uint256);

Description​

This function brings the given amount_ to 18 decimals of precision based on the token_`s decimals. It will revert if the output is zero.

Time complexity​

Constant.

Example​

address token_18_ = address(0x...);
address token_16_ = address(0x...);
address token_20_ = address(0x...);
address token_21_ = address(0x...);

uint256 amount_ = 100;

amount_.to18(token_18_); // 100
amount_.to18(token_16_); // 10000
amount_.to18(token_20_); // 1
amount_.to18(token_21_); // Reverts with: "DecimalsConverter: conversion failed"

to18Safe​

function to18Safe(
    uint256 amount_, 
    uint256 baseDecimals_
) internal pure returns (uint256);

Description​

This function brings the given amount_ to 18 decimals of baseDecimals_. It will revert if the output is zero.

Time complexity​

Constant.

Example​

uint256 amount_ = 100;

amount_.to18(18); // 100
amount_.to18(16); // 10000
amount_.to18(20); // 1
amount_.to18(21); // Reverts with: "DecimalsConverter: conversion failed"

from18​

function from18(
    uint256 amount_, 
    address token_
) internal view returns (uint256);

Description​

This function brings the given amount_ from 18 decimals to the desired decimals of precision based on the token_'s decimals.

Time complexity​

Constant.

Example​

address token_18_ = address(0x...);
address token_16_ = address(0x...);
address token_20_ = address(0x...);
address token_15_ = address(0x...);

uint256 amount_ = 100;

amount_.from18(token_18_); // 100
amount_.from18(token_16_); // 1
amount_.from18(token_20_); // 10000
amount_.from18(token_15_); // 0

from18​

function from18(
    uint256 amount_, 
    uint256 destDecimals_
) internal pure returns (uint256);

Description​

This function brings the given amount_ from 18 decimals to the desired decimals of baseDecimals_.

Time complexity​

Constant.

Example​

uint256 amount_ = 100;

amount_.from18(18); // 100
amount_.from18(16); // 1
amount_.from18(20); // 10000
amount_.from18(15); // 0

from18Safe​

function from18Safe(
    uint256 amount_, 
    address token_
) internal view returns (uint256);

Description​

This function brings the given amount_ from 18 decimals of precision based on the token_`s decimals. It will revert if the output is zero.

Time complexity​

Constant.

Example​

address token_18_ = address(0x...);
address token_16_ = address(0x...);
address token_20_ = address(0x...);
address token_15_ = address(0x...);

uint256 amount_ = 100;

amount_.from18Safe(token_18_); // 100
amount_.from18Safe(token_16_); // 1
amount_.from18Safe(token_20_); // 10000

// Reverts with: "DecimalsConverter: conversion failed"
amount_.from18Safe(token_15_);

to18Safe​

function from18Safe(
    uint256 amount_, 
    uint256 destDecimals_
) internal pure returns (uint256);

Description​

This function brings the given amount_ from 18 decimals of baseDecimals_. It will revert if the output is zero.

Time complexity​

Constant.

Example​

uint256 amount_ = 100;

amount_.from18Safe(18); // 100
amount_.from18Safe(16); // 10000
amount_.from18Safe(20); // 1
amount_.from18Safe(21); // Reverts with: "DecimalsConverter: conversion failed"

round18​

function round18(
    uint256 amount_, 
    address token_
) internal view returns (uint256);

Description​

This function substitutes the trailing digits of an amount_ with zeros, ensuring 18 precision decimals based on the token_'s decimals.

Time complexity​

Constant.

Example​

address token_18_ = address(0x...);
address token_17_ = address(0x...);
address token_16_ = address(0x...);
address token_15_ = address(0x...);
address token_20_ = address(0x...);

uint256 amount_ = 123;

amount_.round18(token_18_); // 123
amount_.round18(token_17_); // 120
amount_.round18(token_16_); // 100
amount_.round18(token_15_); // 0
amount_.round18(token_20_); // 123

round18​

function round18(
    uint256 amount_, 
    uint256 decimals_
) internal pure returns (uint256);

Description​

This function substitutes the trailing digits of an amount_ with zeros, ensuring 18 precision decimals based on the decimals_.

Time complexity​

Constant.

Example​

uint256 amount_ = 123;

amount_.round18(18); // 123
amount_.round18(17); // 120
amount_.round18(16); // 100
amount_.round18(15); // 0
amount_.round18(20); // 123

round18Safe​

function round18Safe(
    uint256 amount_, 
    address token_
) internal view returns (uint256);

Description​

This function substitutes the trailing digits of an amount_ with zeros, ensuring 18 precision decimals based on the token_'s decimals. It will revert if the output is zero.

Time complexity​

Constant.

Example​

address token_18_ = address(0x...);
address token_17_ = address(0x...);
address token_16_ = address(0x...);
address token_15_ = address(0x...);
address token_20_ = address(0x...);

uint256 amount_ = 123;

amount_.round18Safe(token_18_); // 123
amount_.round18Safe(token_17_); // 120
amount_.round18Safe(token_16_); // 100
amount_.round18Safe(token_20_); // 123

// Reverts with: "DecimalsConverter: conversion failed"
amount_.round18Safe(token_15_);

round18Safe​

function round18Safe(
    uint256 amount_, 
    uint256 decimals_
) internal pure returns (uint256);

Description​

This function substitutes the trailing digits of an amount_ with zeros, ensuring 18 precision decimals based on the decimals_. It will revert if the output is zero.

Time complexity​

Constant.

Example​

uint256 amount_ = 123;

amount_.round18Safe(18); // 123
amount_.round18Safe(17); // 120
amount_.round18Safe(16); // 100
amount_.round18Safe(20); // 123
amount_.round18Safe(15); // Reverts with: "DecimalsConverter: conversion failed"

convert​

function convert(
    uint256 amount_,
    address baseToken_,
    address destToken_
) internal view returns (uint256);

Description​

This function converts the amount_ from the precision of the baseToken_ to the precision of the destToken_.

Time complexity​

Constant.

Example​

address token_18_ = address(0x...);
address token_16_ = address(0x...);
address token_20_ = address(0x...);

uint256 amount_ = 100;

amount_.convert(token_18_, token_18_); // 100
amount_.convert(token_18_, token_16_); // 1
amount_.convert(token_16_, token_18_); // 10000
amount_.convert(token_20_, token_16_); // 0
amount_.convert(token_16_, token_20_); // 1000000

convert​

function convert(
    uint256 amount_,
    uint256 baseDecimals_,
    uint256 destDecimals_
) internal pure returns (uint256);

Description​

This function converts the amount_ from the baseDecimals_ to the destDecimals_.

Time complexity​

Constant.

Example​

uint256 amount_ = 100;

amount_.convert(18, 18); // 100
amount_.convert(18, 16); // 1
amount_.convert(16, 18); // 10000
amount_.convert(20, 16); // 0
amount_.convert(16, 20); // 1000000