The use statement
use creates a local alias for a fully qualified namespace or namespaced function. Use it when repeating a long qualified name would make a script harder to read.
Aliases are resolved when the script is compiled. use does not import, load, or register a module.
Alias a namespace
Use a namespace alias as the first segment of a qualified function name:
Here, http::get(...) resolves to io::net::http::get(...).
The syntax is:
For a namespace alias, target is the fully qualified namespace and alias is the shorter name used by the rest of the script.
Alias a function
use can also alias a specific namespaced function. The alias is then called without a namespace prefix:
Here, get(...) resolves to io::net::http::get(...).
Place use before the script body
use declarations belong in the script header. Put them before variable declarations, function declarations, function calls, standalone loops, and return statements.
A script may declare more than one alias:
Resolution rules
- Alias names remain case-sensitive. Registered namespace segments and host-function names are case-insensitive and are documented in canonical lowercase.
- Reusing an alias for a different target produces a compile-time name error.
- An alias does not make its target available. The runtime still needs to register the namespace or function named by the target.
- Runtime capabilities may differ between the CLI, browser runtime, and embedding applications, so an alias can only call functions provided by the current environment.