join_impl 0.3.0

Implementation of the `join!` macro.
Documentation 
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//!
//! `Chain` implemented for `ExprGroup<ActionExpr>` .
//!
pub mod builder;

use crate::chain::expr::ActionExpr;
use crate::chain::group::ExprGroup;
use crate::chain::Chain;
pub use builder::ActionExprChainBuilder;
use syn::PatIdent;

///
/// Chain with members of type `ExprGroup<ActionExpr>` and optional `PatIdent` identifier.
///
pub struct ActionExprChain {
    ident: Option<PatIdent>,
    members: Vec<ExprGroup<ActionExpr>>,
}

///
/// Implementation of `Chain` with `ExprGroup<ActionExpr>` members.
///
impl Chain for ActionExprChain
where
    Self: Sized,
{
    type Member = ExprGroup<ActionExpr>;
    type Identifier = PatIdent;

    fn new(ident: impl Into<Option<PatIdent>>, members: &[ExprGroup<ActionExpr>]) -> Self {
        Self {
            ident: ident.into(),
            members: members.to_vec(),
        }
    }

    fn append_member(&mut self, val: ExprGroup<ActionExpr>) -> usize {
        self.members.push(val);
        self.members.len()
    }

    fn set_id(&mut self, val: impl Into<Option<PatIdent>>) -> &mut Self {
        self.ident = val.into();
        self
    }

    fn members(&self) -> &[Self::Member] {
        &self.members
    }

    fn id(&self) -> Option<&Self::Identifier> {
        self.ident.as_ref()
    }

    fn remove_member(&mut self, idx: usize) -> Option<Self::Member> {
        if idx < self.len() {
            Some(self.members.remove(idx))
        } else {
            None
        }
    }

    fn len(&self) -> usize {
        self.members.len()
    }
}