struct-field-names-as-array

Provides the FieldNamesAsArray procedural macro. The macro adds the FIELD_NAMES_AS_ARRAY constant to the struct the macro is dervied on. The FIELD_NAMES_AS_ARRAY contains the field names of the given struct.

Note: The macro can only be derived from named structs.

Table of Contents

• Usage
• Attributes
  • Container Attributes
    • Rename all
    • Visibility
  • Field Attributes
    • Skip

Usage

You can derive the FieldNamesAsArray macro like this:

use struct_field_names_as_array::FieldNamesAsArray;

#[derive(FieldNamesAsArray)]
struct Foo {
    bar: String,
    baz: String,
    bat: String,
}

assert_eq!(Foo::FIELD_NAMES_AS_ARRAY, ["bar", "baz", "bat"]);

Attributes

The FieldNamesAsArray macro supports the field_names_as_array attribute. field_names_as_array can be applied to the container or to a field with different arguments listed below.

Container Attributes

Container attributes are global attributes that change the behavior of the whole field names array, rather than that of a single field.

Rename all

The rename_all attribute renames every field of the struct according to the provided naming convention. This attribute works exactly like the serde equivalent. Supported are these naming conventions:

• lowercase
• UPPERCASE
• PascalCase
• camelCase
• snake_case
• SCREAMING_SNAKE_CASE
• kebab-case
• SCREAMING-KEBAB-CASE

use struct_field_names_as_array::FieldNamesAsArray;

#[derive(FieldNamesAsArray)]
#[field_names_as_array(rename_all = "SCREAMING-KEBAB-CASE")]
struct Foo {
    field_one: String,
    field_two: String,
    field_three: String,
}

assert_eq!(
  Foo::FIELD_NAMES_AS_ARRAY, 
  ["FIELD-ONE", "FIELD-TWO", "FIELD-THREE"],
);

Note: Same as serde's implementation of rename_all, it is assumed that your field names follow the rust naming convention. Namely, all field names must be given in snake_case. If you don't follow this convention, applying rename_all may result in unexpected field names.

Visibility

Per default, FIELD_NAMES_AS_ARRAY is a private member of the struct. If you want to change the visibility of FIELD_NAMES_AS_ARRAY, you can use the visibility attribute, providing it with a valid visibility:

mod foo {
    use struct_field_names_as_array::FieldNamesAsArray;

    #[derive(FieldNamesAsArray)]
    #[field_names_as_array(visibility = "pub(super)")]
    pub(super) struct Foo {
        bar: String,
        baz: String,
        bat: String,
    }
}

assert_eq!(foo::Foo::FIELD_NAMES_AS_ARRAY, ["bar", "baz", "bat"]);

Field Attributes

Field attributes can be added to the fields of a named struct and change the behavior of a single field.

Skip

The skip attribute removes the field from FIELD_NAMES_AS_ARRAY.

use struct_field_names_as_array::FieldNamesAsArray;

#[derive(FieldNamesAsArray)]
struct Foo {
    bar: String,
    baz: String,
    #[field_names_as_array(skip)]
    bat: String,
}

assert_eq!(Foo::FIELD_NAMES_AS_ARRAY, ["bar", "baz"]);