Macro ea::chain

macro_rules! chain {
    ($function: ident($($params: expr),*)) => { ... };
    (|$($c_params: ident),*| $body: block($($expr: expr),*)) => { ... };
    ((|$($c_params: ident),*| $body: expr)($($expr: expr),*)) => { ... };
    (move |$($c_params: ident),*| $body: block($($expr: expr),*)) => { ... };
    ((move |$($c_params: ident),*| $body: expr)($($expr: expr),*)) => { ... };
    (&|$($c_params: ident),*| $body: block($(*$expr: expr),*)) => { ... };
    ((&|$($c_params: ident),*| $body: expr)($($expr: expr),*)) => { ... };
    (& mut |$($c_params: ident),*| $body: block($($expr: expr),*)) => { ... };
    ((& mut |$($c_params: ident),*| $body: expr)($($expr: expr),*)) => { ... };
    ($function: ident($($params: expr),*), $function2: ident) => { ... };
    ($function: ident($($params: expr),*), |$c_params: ident| $body: expr) => { ... };
    ($function: ident($($params: expr),*), |$c_params: ident: $ty: ident| $body: expr) => { ... };
    ($function: ident($($params: expr),*), |$c_params: ident: & $ty: ident| $body: expr) => { ... };
    ($function: ident($($params: expr),*), |$c_params: ident: & mut $ty: ident| $body: tt) => { ... };
    ($function: ident($($params: expr),*), move |$c_params: ident| $body: tt) => { ... };
    ($function: ident($($params: expr),*), move |$c_params: ident: $ty: ident| $body: tt) => { ... };
    ($function: ident($($params: expr),*), move |$c_params: ident: & $ty: ident| $body: tt) => { ... };
    ($function: ident($($params: expr),*), move |$c_params: ident: & mut $ty: ident| $body: tt) => { ... };
    ($function: ident($($params: expr),*), $function2: ident, $($more_func: ident),+) => { ... };
    ((|$($c_params: ident),*| $body: expr)($($expr: expr),*), $func: ident) => { ... };
    ((move |$($c_params: ident),*| $body: expr)($($expr: expr),*), $func: ident) => { ... };
    ((|$($c_params: ident),*| $body: expr)($($expr: expr),*), |$($c2_params: ident),*| $body2: expr) => { ... };
    ((move |$($c_params: ident),*| $body: expr)($($expr: expr),*), |$c2_params: ident| $body2: expr) => { ... };
    ((|$($c_params: ident: $ty: ty),*| $body: expr)($($expr: expr),*), $func: ident) => { ... };
    ((move |$($c_params: ident: $ty: ty),*| $body: expr)($expr: expr), $func: ident) => { ... };
    ((|$($c_params: ident),*| $body: expr)($($expr: expr),*), |$c2_params: ident| $body2: expr) => { ... };
    ((|$($c_params: ident),*| $body: expr)($($expr: expr),*), move |$c2_params: ident| $body2: expr) => { ... };
    ((move |$($c_params: ident),*| $body: expr)($($expr: expr),*), move |$c2_params: ident| $body2: expr) => { ... };
    ((|$($c_params: ident: $ty: ty),*| $body: expr)($($expr: expr),*), |$c2_params: ident| $body2: expr) => { ... };
    ((move |$($c_params: ident: $ty: ty),*| $body: expr)($($expr: expr),*), |$c2_params: ident| $body2: expr) => { ... };
    ((|$($c_params: ident: $ty: ty),*| $body: expr)($($expr: expr),*), move |$c2_params: ident| $body2: expr) => { ... };
    ((move |$($c_params: ident: $ty: ty),*| $body: expr)($($expr: expr),*), move |$c2_params: ident| $body2: expr) => { ... };
    ((|$($c_params: ident),*| $body: expr)($($expr: expr),*), |$c2_params: ident: $ty: ty| $body2: expr) => { ... };
    ((move |$($c_params: ident),*| $body: expr)($($expr: expr),*), |$c2_params: ident: $ty: ty| $body2: expr) => { ... };
    ((|$($c_params: ident),*| $body: expr)($($expr: expr),*), move |$c2_params: ident: $ty: ty| $body2: expr) => { ... };
    ((move |$($c_params: ident),*| $body: expr)($($expr: expr),*), move |$c2_params: ident: $ty: ty| $body2: expr) => { ... };
    ((|$($c_params: ident: $ty: ty),*| $body: expr)($($expr: expr),*), |$c2_params: ident: $ty2: ty| $body2: expr) => { ... };
    ((move |$($c_params: ident: $ty: ty),*| $body: expr)($($expr: expr),*), |$c2_params: ident: $ty2: ty| $body2: expr) => { ... };
    ((|$($c_params: ident: $ty: ty),*| $body: expr)($($expr: expr),*), move |$c2_params: ident: $ty2: ty| $body2: expr) => { ... };
    ((move |$($c_params: ident: $ty: ty),*| $body: expr)($($expr: expr),*), move |$c2_params: ident: $ty2: ty| $body2: expr) => { ... };
    ($function: ident($($params: expr),*), |$c_params: ident| $body: expr, $($other: tt)*) => { ... };
    ($function: ident($($params: expr),*), move |$c_params: ident| $body: expr, $($other: tt)*) => { ... };
    ((|$($c_params: ident),*| $body: expr)($($expr: expr),*), $function: ident, $($other: tt)*) => { ... };
    ((move |$($c_params: ident),*| $body: expr)($($expr: expr),*), $function: ident, $($other: tt)*) => { ... };
    ((|$($c_params: ident),*| $body: expr)($($expr: expr),*), |$($c2_params: ident),*| $body2: expr, $($other: tt)*) => { ... };
    ((move |$($c_params: ident),*| $body: expr)($($expr: expr),*), |$($c2_params: ident),*| $body2: expr, $($other: tt)*) => { ... };
    ((|$($c_params: ident),*| $body: expr)($($expr: expr),*), move |$c2_params: ident| $body2: expr, $($other: tt)*) => { ... };
    ((move |$($c_params: ident),*| $body: expr)($($expr: expr),*), move |$($c2_params: ident),*| $body2: expr, $($other: tt)*) => { ... };
    ($function: ident($($params: expr),*), |$c_params: ident: $ty: ty| $body: expr, $($other: tt)*) => { ... };
    ($function: ident($($params: expr),*), move |$c_params: ident: $ty: ty| $body: expr, $($other: tt)*) => { ... };
    ((|$($c_params: ident: $ty: ty),*| $body: expr)($($expr: expr),*), $function: ident, $($other: tt)*) => { ... };
    ((move |$($c_params: ident: $ty: ty),*| $body: expr)($($expr: expr),*), $function: ident, $($other: tt)*) => { ... };
    ((|$($c_params: ident),*| $body: expr)($($expr: expr),*), |$c2_params: ident| $body2: expr, $($other: tt)*) => { ... };
    ((move |$($c_params: ident),*| $body: expr)($($expr: expr),*), |$c2_params: ident| $body2: expr, $($other: tt)*) => { ... };
    ((|$($c_params: ident: $ty: ty),*| $body: expr)($($expr: expr),*), |$c2_params: ident| $body2: expr, $($other: tt)*) => { ... };
    ((move |$($c_params: ident: $ty: ty),*| $body: expr)($($expr: expr),*), |$c2_params: ident| $body2: expr, $($other: tt)*) => { ... };
    ((|$($c_params: ident: $ty: ty),*| $body: expr)($($expr: expr),*), move |$c2_params: ident| $body2: expr, $($other: tt)*) => { ... };
    ((move |$($c_params: ident: $ty: ty),*| $body: expr)($($expr: expr),*), move |$c2_params: ident| $body2: expr, $($other: tt)*) => { ... };
    ((|$($c_params: ident),*| $body: expr)($($expr: expr),*), |$c2_param: ident: $ty2: ty| $body2: expr, $($other: tt)*) => { ... };
    ((move |$($c_params: ident),*| $body: expr)($($expr: expr),*), |$c2_param: ident: $ty2: ty| $body2: expr, $($other: tt)*) => { ... };
    ((|$($c_params: ident),*| $body: expr)($($expr: expr),*), move |$c2_param: ident: $ty2: ty| $body2: expr, $($other: tt)*) => { ... };
    ((move |$($c_params: ident),*| $body: expr)($($expr: expr),*), move |$c2_param: ident: $ty2: ty| $body2: expr, $($other: tt)*) => { ... };
    ((|$($c_params: ident: $ty: ty),*| $body: expr)($($expr: expr),*), |$c2_param: ident: $ty2: ty| $body2: expr, $($other: tt)*) => { ... };
    ((move |$($c_params: ident: $ty: ty),*| $body: expr)($($expr: expr),*), |$c2_param: ident: $ty2: ty| $body2: expr, $($other: tt)*) => { ... };
    ((|$($c_params: ident: $ty: ty),*| $body: expr)($($expr: expr),*), move |$c2_param: ident: $ty2: ty| $body2: expr, $($other: tt)*) => { ... };
    ((move |$($c_params: ident: $ty: ty),*| $body: expr)($($expr: expr),*), move |$c2_param: ident: $ty2: ty| $body2: expr, $($other: tt)*) => { ... };
}

A macro counterpart of function chain which reduce verbosity and defer the execution until entire chain is formed.

This macro will expanded to a nested function call, not a (Chainable)[struct.Chainable.html] struct.

For example:

use ea::chain;
let result = chain!((|a, b, c| a + b + c)(1i32, 2, 3), |d| d * 2);
assert_eq!(12, result);
// The macro will expand into something like this
assert_eq!(
    12,
    (|d| d * 2)((|a, b, c| a + b + c)(1i32, 2, 3))
);

Another example using function:

use ea::chain;
fn function(a : i32, b : i32, c : i32) -> i32{
    a + b + c
}
fn subsequence_function(d: i32) -> i32 {
    d * 2
}
let outer = 2;
let result = chain!(
                function(1, 2, 3), 
                |e| e + 1, 
                move |f| f * outer, 
                subsequence_function, 
                subsequence_function);
assert_eq!(56, result);
// This macro will be expanded to:
assert_eq!(56, 
    subsequence_function(
        subsequence_function(
            (move |f| f * outer)(
                (|e| e + 1)(
                    function(1, 2, 3)
                )
            )
        )
    )
)