wasm/

README

Smart Contracts

Note that most example smart contracts only show the concepts involved in creating them but should not be taken as fully functional code yet.

Sample smart contracts:

• dividend

  Allows for setting up automatic dividend dispersal to a number of recipients according to distribution factors per recipient. Any tokens sent to this contract will automatically be divided accordingly over these recipients.

• donatewithfeedback

  Allows for donations and registers feedback associated with the donation. The contract owner can at any point decide to withdraw donated funds from the contract.

• erc20

  Experimental implementation of an ERC20 smart contract as first introduced by Ethereum.

• fairauction

  Allows an auctioneer to auction a number of tokens. The contract owner takes a small fee. The contract guarantees that the tokens will be sent to the highest bidder, and that the losing bidders will be completely refunded. Everyone involved stakes their tokens, so there is no possibility for anyone to cheat.

• fairroulette

  A simple betting contract. Betters can bet on a random color and after a predefined time period the contract will automatically pay the total bet amount proportionally to the bet size of the winners.

• helloworld

  ISC version of the ubiquitous "Hello, world!" program.

• inccounter

  A simple test contract. All it does is increment a counter value. It is also used to test basic ISC capabilities, like persisting state, batching requests, and sending (time-locked) requests from a contract.

• testcore

  Helper smart contract to test the ISC core functionality.

• testwasmlib

  Helper smart contract to test the WasmLib functionality.

• tokenregistry

  Mints and registers colored tokens in a token registry.

How to create your own Rust smart contracts

Prerequisites:

• install the latest Rust tools, you can find them here.
• When installing under Windows the Rust installation program may tell you that you need the Visual Studio C++ Build Tools, which you can download here. Note that you only need to install the C++ build tools, which is the top-left selection.
• install Wasm-pack, which can be downloaded here.

Building a Rust smart contract is very simple when using the Rust plugin in any IntelliJ based development environment. Open the contracts/wasm sub folder in your IntelliJ, which then provides you with the Rust workspace.

The easiest way to create a new contract is to copy the helloworld folder to a properly named new folder within the rust sub folder. Next, change the fields in the first section of the new folder's cargo.toml file to match your preferences. Make sure the package name equals the folder name. Finally, add the new folder to the workspace in the cargo.toml in the contracts/wasm folder.

To build the new smart contract select Run->Edit Configurations. Add a new configuration based on the wasmpack template, type the name of the new configuration, type the command build, and select the new folder as the working directory. You can now run this configuration to compile the smart contract directly to Wasm. Once compilation is successful you will find the resulting Wasm file in the pkg sub folder of the new folder.