Standard Library

The Ursus Standard Library provides essential types, functions, and operators for smart contract development. It includes primitives, data structures, and platform-specific functionality.

Overview

The standard library is organized into several modules:

1. Primitives - Basic types (integers, booleans, addresses, strings)
2. Functions - Standard functions (math, crypto, conversions)
3. Operators - Arithmetic, logical, bitwise, comparison operators
4. TVM Functions - TON Virtual Machine specific functions

Library Structure

ursus-standard-library/
├── src/
│   ├── Solidity/        # Solidity-compatible library
│   ├── Rust/            # Rust-compatible library
│   └── _Cpp/            # C++ (TON) compatible library

Each target language has its own standard library variant with platform-specific implementations.

Importing the Standard Library

Basic Import

Require Import UrsusEnvironment.Solidity.current.Environment.
Require Import UrsusEnvironment.Solidity.current.LocalGenerator.

Specific Modules

Require Import Ursus.Stdlib.Primitives.
Require Import Ursus.Stdlib.Functions.
Require Import Ursus.Stdlib.Operators.

TVM-Specific

Require Import UrsusEnvironment.Cpp.current.Environment.
Require Import Ursus.TVM.Functions.

Primitive Types

Integer Types

Unsigned integers:

• uint8, uint16, uint32, uint64, uint128, uint256

Signed integers:

• int8, int16, int32, int64, int128, int256

Example:

::// var 'balance : uint256 := {1000} .
::// var 'delta : int256 := {-50} .

Boolean Type

boolean  (* true or false *)

Example:

::// var 'isActive : boolean := @true .
::// var 'hasPermission : boolean := @false .

Address Type

address  (* Blockchain address *)

Example:

::// var 'owner : address := msg->sender .
::// var 'recipient : address := {0x742d35Cc6634C0532925a3b844Bc9e7595f0bEb} .

String Type

string  (* UTF-8 string *)

Example:

::// var 'name : string := "MyToken" .
::// var 'symbol : string := "MTK" .

Complex Types

Mapping

Syntax:

mapping KeyType ValueType

Examples:

balances : mapping address uint256
allowances : mapping address (mapping address uint256)

Usage:

::// var 'balance : uint256 := balances[[addr]] .
::// balances[[addr]] := {1000} .

Optional

Syntax:

optional T

Example:

::// var 'maybeValue : optional uint256 := Some {42} .
::// var 'nothing : optional uint256 := None .

Arrays

Syntax:

array T

Example:

::// var 'items : array uint256 := [] .
::// items := items ++ [{1}, {2}, {3}] .

Common Functions

Mathematical Functions

min(a, b)      (* Minimum of two values *)
max(a, b)      (* Maximum of two values *)
abs(x)         (* Absolute value *)

Example:

::// var 'smaller : uint256 := min(x, y) .
::// var 'larger : uint256 := max(x, y) .

Cryptographic Functions

keccak256(data)    (* Keccak-256 hash *)
sha256(data)       (* SHA-256 hash *)
ripemd160(data)    (* RIPEMD-160 hash *)

Example:

::// var 'hash : uint256 := keccak256(data) .

Conversion Functions

uint256(x)     (* Convert to uint256 *)
int256(x)      (* Convert to int256 *)
address(x)     (* Convert to address *)

Example:

::// var 'addr : address := address(uint256Value) .

Operators

Arithmetic

a + b          (* Addition *)
a - b          (* Subtraction *)
a * b          (* Multiplication *)
a / b          (* Division *)
a % b          (* Modulo *)

Comparison

a == b         (* Equal *)
a != b         (* Not equal *)
a < b          (* Less than *)
a > b          (* Greater than *)
a <= b         (* Less or equal *)
a >= b         (* Greater or equal *)

Logical

a && b         (* Logical AND *)
a || b         (* Logical OR *)
!a             (* Logical NOT *)

Bitwise

a & b          (* Bitwise AND *)
a | b          (* Bitwise OR *)
a ^ b          (* Bitwise XOR *)
~a             (* Bitwise NOT *)
a << n         (* Left shift *)
a >> n         (* Right shift *)

Message Context

Access transaction information:

msg->sender    (* Sender address *)
msg->value     (* Sent value *)
msg->data      (* Message data *)

Example:

::// var 'caller : address := msg->sender .
::// var 'payment : uint256 := msg->value .

Contract Context

Access contract information:

this->address  (* Contract address *)
this->balance  (* Contract balance *)

Example:

::// var 'contractAddr : address := this->address .
::// var 'funds : uint256 := this->balance .

Platform-Specific Libraries

Solidity Standard Library

Located in ursus-standard-library/src/Solidity/:

• EVM-compatible types
• Solidity-style functions
• Gas-optimized operations

C++ (TON) Standard Library

Located in ursus-standard-library/src/_Cpp/:

• TVM-compatible types
• TON-specific functions
• Cell operations

Rust Standard Library

Located in ursus-standard-library/src/Rust/:

• Rust-compatible types
• Safe operations
• Modern syntax

Next Steps

• Primitives - Detailed primitive types
• Functions - All standard functions
• Operators - Complete operator reference
• TVM Functions - TON-specific functionality

See Also

• Ursus Language - Language reference
• Writing Functions - Function development
• ursus-patterns repository - Usage examples