ArcJs 2

This is a proof of concept for an alternative design for Arc.js. This means that most of the things are implemeted as stubs, except for the general architecture and a small subset of things that serve as examples on how the rest of the library would look like.

The need for such a design was motivated by these main common problems in alchemy:

• Pointer chaing.
• Handling changes.

Moreover I feel that the current Arc.js does not provide much abstraction over the backend. While using the current library, you still need to know a lot of things about how Arc works to be able to use it correctly.

Benefits:

• Nice modular and composable API.
• Fully abstracts the "contracts as a service" design of Arc.
• Automatically verifies (also a security feature) and casts contracts addresses to their appropriate wrapper, by comparing the code at the address to deployedBytecode from known contracts.
• Extensible - allows the user to dynamically register new types of global constraints and schemes.
• Integrates well with popular frontend frameworks by treating properties of contracts as rxjs.Observables:
  • In Angular2 it's easy to bind the value of theses properties in the template by using the async pipe:

      <span>{{someProperty | async}}</span>

    This way the property is automatically updated in real-time.
  • Using redux-observable we can simple map property Observables to a stream of ON_CHANGE actions.
  • With React, we can simply use existing wrapper components from a library (like Frint) to map observable values to props for a component:

      const WrappedComponent = observe(() => someProperty.map(mapToProps))(Component);

  • We can also always simply convert an Observable to a regular Promise by observable.toPromise().
• Validates Arc-specific errors and raises an exception as early as possible (e.g. registering a SchemeRegistrar without the required permissions).
• Simulates transactions before sending to catch reverts before they reach the blockchain.
• Automatically sets the gas limit for a transaction to be exactly the gas it will spend in order to prevent loss of funds.
• Informative error messages that specify the contract address, method name, and arguments which led to a revert.
• Set of utility functions for easily writing new wrappers for custom schemes and global constraints.