Require

Require

This module provides convenience functionality to be used in combination with the Requires.jl package.

require(mod, packages; [fun_name]::String="", [explanation]::String="")

Check for one or more optional packages and print an error message if any of them is not loaded.

Input

• mod – module where the package should be loaded; use @__MODULE__
• packages – symbol or list of symbols (the package name(s))
• fun_name – (optional; default: "") name of the function that requires the package
• explanation – (optional; default: "") additional explanation in the error message
• require_all – (optional; default: true) flag to require all packages

Output

If all packages are loaded, this function has no effect. Otherwise, it prints an error message.

Notes

The argument mod should typically be @__MODULE__, but since this is a macro, it has to be inserted by the caller.

The argument require_all can be set to false to require only one of the given packages. This is useful if multiple packages provide a functionality and any of them is fine.

This function uses @assert and hence loses its ability to print an error message if assertions are deactivated (see the Assertions module).

See also the @required macro for a more concise syntax.

@required(package)

Check for an optional package and print an error message if any of them is not loaded.

Input

• package – package name

Output

If the package is loaded, this macro has no effect. Otherwise, it prints an error message.

This macro uses @assert and hence loses its ability to print an error message if assertions are deactivated (see the Assertions module).

See also the require function for a more customizable version.