Struct former::exposed::HashSetSubformer

pub struct HashSetSubformer<E, Formed, Context, ContainerEnd>
where
    E: Eq + Hash,
    Formed: HashSetLike<E> + Default,
    ContainerEnd: FormingEnd<Formed, Context>,
{ /* private fields */ }

Facilitates building HashSetLike containers with a fluent API.

HashSetSubformer leverages the HashSetLike trait to enable a concise and expressive way of populating HashSet-like containers. It exemplifies the crate’s builder pattern variation for sets.

Example Usage

Using HashSetSubformer to populate a HashSet within a struct:

#[ derive( Debug, PartialEq, former::Former ) ]
pub struct StructWithSet
{
  #[ subformer( former::HashSetSubformer ) ]
  set : std::collections::HashSet< &'static str >,
}

let instance = StructWithSet::former()
.set()
  .insert( "apple" )
  .insert( "banana" )
  .end()
.form();

assert_eq!(instance, StructWithSet { set : hset![ "apple", "banana" ] });

Implementations

impl<E, Formed, Context, ContainerEnd> HashSetSubformer<E, Formed, Context, ContainerEnd>

where E: Eq + Hash, Formed: HashSetLike<E> + Default, ContainerEnd: FormingEnd<Formed, Context>,

pub fn form(self) -> Formed

Form current former into target structure.

pub fn begin( formed: Option<Formed>, context: Option<Context>, on_end: ContainerEnd ) -> Self

Begins the building process with an optional context and formed.

This method is typically called internally by the builder but can be used directly to initialize the builder with specific contexts or containers.

Parameters

• context: An optional context for the building process.
• formed: An optional initial formed to populate.
• on_end: A handler to be called at the end of the building process.

pub fn end(self) -> Context

Finalizes the building process and returns the constructed formed or a context.

This method concludes the building process by applying the on_end handler to transform the formed or incorporate it into a given context. It’s typically called at the end of the builder chain to retrieve the final product of the building process.

Returns

Depending on the on_end handler’s implementation, this method can return either the constructed formed or a context that incorporates the formed.

pub fn replace(self, formed: Formed) -> Self

Replaces the current formed with a new one.

This method allows for replacing the entire set being built with a different one. It can be useful in scenarios where a pre-populated set needs to be modified or replaced entirely during the building process.

Parameters

• formed: The new formed to use for subsequent builder operations.

Returns

The builder instance with the formed replaced, enabling further chained operations.

impl<E, Formed> HashSetSubformer<E, Formed, Formed, ReturnFormed>

where E: Eq + Hash, Formed: HashSetLike<E> + Default,

pub fn new() -> Self

Initializes a new instance of the builder with default settings.

This method provides a starting point for building a HashSetLike formed using a fluent interface. It sets up an empty formed ready to be populated.

Returns

A new instance of HashSetSubformer with no elements.

impl<E, Formed, Context, ContainerEnd> HashSetSubformer<E, Formed, Context, ContainerEnd>

where E: Eq + Hash, Formed: HashSetLike<E> + Default, ContainerEnd: FormingEnd<Formed, Context>,

pub fn insert<E2>(self, element: E2) -> Self

where E2: Into<E>,

Inserts an element into the set, possibly replacing an existing element.

This method ensures that the set contains the given element, and if the element was already present, it might replace it depending on the formed’s behavior.

Parameters

• element: The element to insert into the set.

Returns

• Some(element) if the element was replaced.
• None if the element was newly inserted without replacing any existing element.

Trait Implementations

impl<E, Formed, Context: Debug, ContainerEnd> Debug for HashSetSubformer<E, Formed, Context, ContainerEnd>

where E: Eq + Hash + Debug, Formed: HashSetLike<E> + Default + Debug, ContainerEnd: FormingEnd<Formed, Context> + Debug,

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<E, Formed, Context: Default, ContainerEnd> Default for HashSetSubformer<E, Formed, Context, ContainerEnd>

where E: Eq + Hash + Default, Formed: HashSetLike<E> + Default + Default, ContainerEnd: FormingEnd<Formed, Context> + Default,

fn default() -> HashSetSubformer<E, Formed, Context, ContainerEnd>

Returns the “default value” for a type.