# Entitysets Enum
Under the `<Schema>` element in the OData service document, there is an `<EntityContainer>` element.
All entity sets available through this OData service are identified here with their own `<EntitySet Name="...">` tag.
All the `<EntitySet>` elements are listed in an `enum` called `<odata_service_name>Entities`.
For example, the entity sets belonging to the OData service `GWSAMPLE_BASIC` become the following `enum`:
```rust
#[derive(Copy, Clone, Debug)]
pub enum GwsampleBasicEntities {
BusinessPartnerSet,
ProductSet,
SalesOrderSet,
SalesOrderLineItemSet,
ContactSet,
VhSexSet,
VhCountrySet,
VhAddressTypeSet,
VhCategorySet,
VhCurrencySet,
VhUnitQuantitySet,
VhUnitWeightSet,
VhUnitLengthSet,
VhProductTypeCodeSet,
VhBpRoleSet,
VhLanguageSet,
}
```
## Convenience Functions
Three convenience functions are then implemented for `enum GwsampleBasicEntities`:
```rust
impl GwsampleBasicEntities {
pub fn iterator() -> impl Iterator<Item = GwsampleBasicEntities> { /* SNIP */ }
pub const fn variant_name(&self) -> &'static str { /* SNIP */ }
pub fn variant_names() -> Vec<&'static str> { /* SNIP */ }
}
```
## Entitysets Enum `iterator` function
An `iterator` over the `enum` variants has been implemented.
```rust
pub fn iterator() -> impl Iterator<Item = GwsampleBasicEntities> {
[
GwsampleBasicEntities::BusinessPartnerSet,
GwsampleBasicEntities::ProductSet,
GwsampleBasicEntities::SalesOrderSet,
GwsampleBasicEntities::SalesOrderLineItemSet,
GwsampleBasicEntities::ContactSet,
GwsampleBasicEntities::VhSexSet,
GwsampleBasicEntities::VhCountrySet,
GwsampleBasicEntities::VhAddressTypeSet,
GwsampleBasicEntities::VhCategorySet,
GwsampleBasicEntities::VhCurrencySet,
GwsampleBasicEntities::VhUnitQuantitySet,
GwsampleBasicEntities::VhUnitWeightSet,
GwsampleBasicEntities::VhUnitLengthSet,
GwsampleBasicEntities::VhProductTypeCodeSet,
GwsampleBasicEntities::VhBpRoleSet,
GwsampleBasicEntities::VhLanguageSet,
]
.iter()
.copied()
}
```
## Entitysets Enum `variant_name` function
This function returns the name of the entity set variant:
```rust
pub const fn variant_name(&self) -> &'static str {
match *self {
GwsampleBasicEntities::BusinessPartnerSet => "BusinessPartnerSet",
GwsampleBasicEntities::ProductSet => "ProductSet",
GwsampleBasicEntities::SalesOrderSet => "SalesOrderSet",
GwsampleBasicEntities::SalesOrderLineItemSet => "SalesOrderLineItemSet",
GwsampleBasicEntities::ContactSet => "ContactSet",
GwsampleBasicEntities::VhSexSet => "VH_SexSet",
GwsampleBasicEntities::VhCountrySet => "VH_CountrySet",
GwsampleBasicEntities::VhAddressTypeSet => "VH_AddressTypeSet",
GwsampleBasicEntities::VhCategorySet => "VH_CategorySet",
GwsampleBasicEntities::VhCurrencySet => "VH_CurrencySet",
GwsampleBasicEntities::VhUnitQuantitySet => "VH_UnitQuantitySet",
GwsampleBasicEntities::VhUnitWeightSet => "VH_UnitWeightSet",
GwsampleBasicEntities::VhUnitLengthSet => "VH_UnitLengthSet",
GwsampleBasicEntities::VhProductTypeCodeSet => "VH_ProductTypeCodeSet",
GwsampleBasicEntities::VhBpRoleSet => "VH_BPRoleSet",
GwsampleBasicEntities::VhLanguageSet => "VH_LanguageSet",
}
}
```
## Entitysets Enum `variant_names` function
By making use of the above `iterator` and `variant_name` functions, the `variant_names` function returns a vector of entity set names.
```rust
pub fn variant_names() -> Vec<&'static str> {
GwsampleBasicEntities::iterator().fold(Vec::new(), |mut acc: Vec<&'static str>, es| {
acc.push(&mut es.variant_name());
acc
})
}
```