├── .gitignore
├── Cargo.toml
├── README.md
├── examples
    └── simple.rs
└── src
    └── lib.rs


/.gitignore:
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1 | /target
2 | /Cargo.lock
3 | 


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/Cargo.toml:
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1 | [package]
2 | 
3 | name = "fallthrough"
4 | version = "0.0.1"
5 | authors = ["Joshua Yanovski <pythonesque@gmail.com>"]
6 | 


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/README.md:
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 1 | # Fallthrough
 2 | 
 3 | A macro providing fallthrough `match`.
 4 | 
 5 | ## Requirements
 6 | 
 7 | Include the following in your `Cargo.toml`:
 8 | 
 9 | ```toml
10 | [dependencies.fallthrough]
11 | git = "https://github.com/pythonesque/fallthrough"
12 | version = "0.0.1"
13 | ```
14 | 
15 | In your `lib.rs`:
16 | 
17 | ```rust
18 | #[macro_use] extern crate fallthrough;
19 | ```
20 | 
21 | ## Usage
22 | 
23 | ```rust
24 | #[allow(unreachable_code)]
25 | fn main() {
26 |     let mut x = 0;
27 | 
28 |     match_fallthrough!(x, {
29 |         0 => { assert_eq!(x,0); x = 1; },
30 |         1 => { assert_eq!(x,1); x = 2; break; },
31 |         _ => { panic!("Should not reach the default case"); },
32 |     });
33 |     assert_eq!(x, 2);
34 | }
35 | ```
36 | 


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/examples/simple.rs:
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 1 | #[macro_use] extern crate fallthrough;
 2 | 
 3 | #[allow(unreachable_code)]
 4 | fn main() {
 5 |     let mut x = 0;
 6 | 
 7 |     match_fallthrough!(x, {
 8 |         0 => { assert_eq!(x,0); x = 1; },
 9 |         1 => { assert_eq!(x,1); x = 2; break; },
10 |         _ => { panic!("Should not reach the default case"); },
11 |     });
12 |     assert_eq!(x, 2);
13 | }
14 | 


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/src/lib.rs:
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 1 | #[macro_export]
 2 | macro_rules! match_fallthrough_make_match {
 3 |     ($elem:expr, ($($pat:pat => $branch:expr)*)) => {{
 4 |         match $elem {$(
 5 |             $pat => $branch,
 6 |         )*}
 7 |     }}
 8 | }
 9 | 
10 | #[macro_export]
11 | macro_rules! match_fallthrough_make_loops {
12 |     ($test:expr, $exit:expr, ($pat:pat => $branch:expr); ($($p:pat => $r:expr)*)) => {{
13 |         'fallthrough: loop {
14 |             loop {
15 |                 match_fallthrough_make_match!($test, ($pat => break 'fallthrough $($p => $r)*));
16 |             }
17 |             $exit
18 |         }
19 |         $branch
20 |     }};
21 |     ($test:expr, $exit:expr, ($pat:pat => $branch:expr, $($pu:pat => $bu:expr),+) ; ($($p:pat => $r:expr)*)) => {{
22 |         'fallthrough: loop {
23 |             loop {
24 |                 match_fallthrough_make_loops!($test, $exit, ($($pu => $bu),+) ; ($pat => break 'fallthrough $($p => $r)*));
25 |                 break 'fallthrough
26 |             }
27 |             $exit
28 |         }
29 |         $branch
30 |     }};
31 | }
32 | 
33 | #[macro_export]
34 | macro_rules! match_fallthrough_reverse_branches {
35 |     ($test:expr, ($pat:pat => $branch:expr); ($($p:pat => $r:expr)*)) => {{
36 |         'exit: loop {
37 |             match_fallthrough_make_loops!($test, break 'exit, ($pat => $branch, $($p => $r),*); ());
38 |             break;
39 |         }
40 |     }};
41 |     ($test:expr, ($pat:pat => $branch:expr, $($pu:pat => $bu:expr),+); ($($p:pat => $r:expr)*)) => ((
42 |         match_fallthrough_reverse_branches!($test, ( $($pu => $bu),+ ) ; ($pat => $branch $($p => $r)*))
43 |     ))
44 | }
45 | 
46 | #[macro_export]
47 | macro_rules! match_fallthrough {
48 |     ($test:expr, { $( $pat:pat => $branch:expr ),+ } ) => {{
49 |         match_fallthrough_reverse_branches!($test, ($($pat => $branch),+); ())
50 |     }};
51 |     ($test:expr, { $( $pat:pat => $branch:expr, )+ } ) => {{
52 |         match_fallthrough_reverse_branches!($test, ($($pat => $branch),+); ())
53 |     }}
54 | }
55 | 
56 | #[test]
57 | #[allow(unreachable_code)]
58 | fn it_works() {
59 |     let mut x = 0;
60 | 
61 |     match_fallthrough!(x, {
62 |         0 => { assert_eq!(x,0); x = 1; },
63 |         1 => { assert_eq!(x,1); x = 2; break; },
64 |         _ => { panic!("Should not reach the default case"); },
65 |     });
66 |     assert_eq!(x, 2);
67 | }
68 | 


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