Idea: add static type analysis

[kantord]

This feature would consist in 3 different parts:

• Add a syntax for type casting (it should actually be a special way to use functions that take a value and either return a casted value or throw an exception). It should handle type arguments, for example, array of string vs array of integer
• Add casting functions for basic types (integer, array, etc.)
• A static type checker as a separate package that can be used to find errors and generate flow/typescript types for the entire application (or modules)

[kantord]

A simplified version of this might be just adding optional type notations to nested object projection, for example:

${
 author {
    (string) name
    (number) age
  }
}

These could be handled by a special function (passed to the compiler) that could produce TypeScript/flow annotations, while ignored by the interpreter