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use context::{Context};
use std::vec::Vec;
use std::cell::Cell;
pub type Middleware<T> = fn(T, chain: &MiddlewareChain<T>) -> T;
pub struct MiddlewareChain<T: Context> {
_chain_index: Cell<usize>,
pub middleware: Vec<Middleware<T>>
}
impl<T: Context> MiddlewareChain<T> {
pub fn new(middleware: Vec<Middleware<T>>) -> MiddlewareChain<T> {
MiddlewareChain {
middleware: middleware,
_chain_index: Cell::new(0)
}
}
pub fn next(&self, context: T) -> T {
let next_middleware = self.middleware.get(self._chain_index.get());
self._chain_index.set(self._chain_index.get() + 1);
match next_middleware {
Some(middleware) => middleware(context, self),
None => context
}
}
}