Macro extensions_options

macro_rules! extensions_options {
    (
     $(#[doc = $struct_d:tt])*
     $vis:vis struct $struct_name:ident {
        $(
        $(#[doc = $d:tt])*
        $field_vis:vis $field_name:ident : $field_type:ty, default = $default:expr
        )*$(,)*
    }
    ) => { ... };
}

Convenience macro to create ExtensionsOptions.

The created structure implements the following traits:

• Clone
• Debug
• Default
• ExtensionOptions

Usage

The syntax is:

extensions_options! {
     /// Struct docs (optional).
    [<vis>] struct <StructName> {
        /// Field docs (optional)
        [<vis>] <field_name>: <field_type>, default = <default_value>

        ... more fields
    }
}

The placeholders are:

• [<vis>]: Optional visibility modifier like pub or pub(crate).
• <StructName>: Struct name like MyStruct.
• <field_name>: Field name like my_field.
• <field_type>: Field type like u8.
• <default_value>: Default value matching the field type like 42.

Example

use datafusion_common::extensions_options;

extensions_options! {
    /// My own config options.
    pub struct MyConfig {
        /// Should "foo" be replaced by "bar"?
        pub foo_to_bar: bool, default = true

        /// How many "baz" should be created?
        pub baz_count: usize, default = 1337
    }
}