Namespace

A namespace is a declarative region that provides a scope to the identifiers and contents. Namespace is block level element. Different files can have the same namespace declared.

Namespace looks like this in schema:

model User {
    @id @autoIncrement @readonly
    id: Int
    email: String
}
 
namespace admin {
    model User {
        @id @autoIncrement @readonly
        id: Int
        email: String
    }
}

In this piece of schema, User and admin.User are two different models.

Preventing name conflicts

If two different models share the same name in any reason, namespace can be used to prevent name conflicts. In the future, when packages are supported by Teo, each package must declare a unique namespace to wrap its contents including models, enums and pipeline items.

URL path

Each namespace has different namespace prefixes in request URLs. To access APIs for User in previous code snippet, post to /User/{handlerName}, to access APIs for admin.User, post to /User/{handlerName}.

Connector inheritance

Teo supports multiple databases. Each namespace can have zero or one connector. If a namespace doesn't have a database connector defined, the one from the parent namespace is inherited. Teo can be used without any database connections. When used without namespaces, model definitions are not available.

Main namespace

The root level namespace, although without any namespace declarations, is the main namespace. If developer doesn't declare any namespaces in the schema files, every element is defined in the main namespace. In the previous code, the outer level User is defined in the main namespace.

std namespace

The standard library of Teo resides in the std namespace. This namespace has a special resolving rule that any identifier doesn't exist in the namespace tree will be finally resolved in the std namespace. That is, everything from this core library namespace doesn't need to be prefixed. In the previous code snippet, the decorators @id, @readonly and @autoIncrement are from the std namespace and defined by the core library.

Reserved namespace names

The name main and std are reserved. main is for the outer most level namespace, aka user's main namespace. std is the name of the namespace where core library is in. Any other names are allowed as long as it doesn't conflict with other constants, models, enums, interfaces and configs.

Why namespace?

Teo request handlers are accessible by HTTP requests, and Teo models represent a table or collection in the namespace. The traditional Node.js and Python way of importing can solve name conflicts for constants and variables. It cannot solve handler URL and database table name problem. That's why we decide to use this C++ or TypeScript style namespace.