Macro impl_field_display 

macro_rules! impl_field_display {
    ($enum_name:ident, $( $variant:ident => $name:literal ),* ) => { ... };
}

Implements std::fmt::Display for a field enum with complex (nested) variants.

This macro handles field enums that contain both simple variants (e.g., Title) and complex variants that hold a Vec of sub-fields (e.g., User(Vec<UserField>)).

• For simple variants, it relies on strum’s AsRefStr trait to produce the camelCase string.
• For complex variants, it formats them as fieldName(subField1,subField2,...).

Arguments

• $enum_name:ident - The name of the enum to implement Display for.
• $( $variant:ident => $name:literal ),* - A comma-separated list of the complex variants. Each entry specifies the VariantName and the exact string literal to use for its name.

Example

// An enum with simple and complex variants
use wp_mini::impl_field_display;

#[derive(strum_macros::AsRefStr)]
#[strum(serialize_all = "camelCase")]
enum StoryField {
    Title,
    VoteCount,
    // A complex variant with sub-fields
    User(Vec<UserField>),
}

#[derive(strum_macros::AsRefStr)]
#[strum(serialize_all = "camelCase")]
enum UserField {
    Username,
    Avatar,
}

// Generate the Display implementation using the macro
impl_field_display!(StoryField, User => "user");

// --- Verification ---
// Simple field
let simple_field = StoryField::VoteCount;
assert_eq!(simple_field.to_string(), "voteCount");

// Complex field
let complex_field = StoryField::User(vec![UserField::Username, UserField::Avatar]);
assert_eq!(complex_field.to_string(), "user(username,avatar)");