Skip to main content

ResultIterExt

Trait ResultIterExt 

Source
pub trait ResultIterExt<T, Err>: Iterator<Item = Result<T, Err>> + Sized {
    // Provided methods
    fn unwrap_items(self) -> impl Iterator<Item = T>
       where T: Debug,
             Err: Debug { ... }
    fn collect_vec_result(self) -> Result<Vec<T>, Err> { ... }
}

Provided Methods§

Source

fn unwrap_items(self) -> impl Iterator<Item = T>
where T: Debug, Err: Debug,

Examples found in repository?
examples/test.rs (line 16)
9pub fn main() {
10    println!("Opening midi...");
11    let file = MIDIFile::open("/run/media/d/Midis/The Quarantine Project.mid", None).unwrap();
12    let now = Instant::now();
13    let mut nc: u64 = 0;
14
15    println!("Creating parsers...");
16    let merged = file.iter_all_track_events_merged().unwrap_items();
17    println!("Parsing midi...");
18
19    for e in merged {
20        if let Event::NoteOn(_) = e.as_event() {
21            nc += 1;
22        }
23    }
24
25    println!("Finished parsing midi, found {nc} notes");
26    println!("Elapsed {:?}", now.elapsed());
27    println!(
28        "Notes/second {}",
29        (nc as f64 / now.elapsed().as_secs_f64()).round()
30    );
31}
More examples
Hide additional examples
examples/polyphony.rs (line 11)
5pub fn main() {
6    println!("Opening midi...");
7    let file = MIDIFile::open_in_ram("D:/Midis/tau2.5.9.mid", None).unwrap();
8    println!("Parsing midi...");
9    let now = Instant::now();
10    let mut poly: u64 = 0;
11    let merged = file.iter_all_tracks().merge_all().unwrap_items();
12
13    let mut max_poly: u64 = 0;
14
15    for e in merged {
16        match *e {
17            Event::NoteOn(_) => {
18                poly += 1;
19                if poly > max_poly {
20                    max_poly = poly;
21                }
22            }
23            Event::NoteOff(_) => poly -= 1,
24            _ => {}
25        }
26    }
27
28    println!("Finished parsing midi, found {max_poly} polyphony");
29    println!("Elapsed {:?}", now.elapsed());
30}
examples/nps_bench.rs (line 23)
9pub fn main() {
10    println!("Opening midi...");
11    let midi = MIDIFile::open_in_ram(
12        "/mnt/fat/Midis/Ra Ra Rasputin Ultimate Black MIDI Final.mid",
13        None,
14    )
15    .unwrap();
16
17    let ppq = midi.ppq();
18    let merged = midi
19        .iter_all_track_events_merged_batches()
20        .cast_event_delta::<f64>()
21        .cancel_tempo_events(250000)
22        .scale_event_time(1.0 / ppq as f64)
23        .unwrap_items();
24
25    println!("Tracks: {}", midi.track_count());
26
27    let start = Instant::now();
28    let mut note_count = 0;
29    for batch in merged {
30        for e in batch.iter_events() {
31            if let Event::NoteOn(_) = e.as_event() {
32                note_count += 1;
33            }
34        }
35    }
36
37    println!("Note count: {}   \tTime: {:?}", note_count, start.elapsed());
38    println!(
39        "Notes per second: {}",
40        note_count as f64 / start.elapsed().as_secs_f64()
41    );
42}
examples/write.rs (line 22)
9pub fn main() {
10    println!("Opening midi...");
11    let file = MIDIFile::open_in_ram("D:/Midis/tau2.5.9.mid", None).unwrap();
12    let writer = MIDIWriter::new("./out.mid", file.ppq()).unwrap();
13    println!("Parsing midi...");
14    let now = Instant::now();
15
16    let mut nc: u64 = 0;
17    {
18        let mut track_writer = writer.try_open_next_track().unwrap();
19        // let merged = pipe!(file.iter_all_tracks()|>to_vec()|>merge_events_array()|>unwrap_items());
20        let converted = file.iter_all_tracks();
21        // .map(|track| pipe!(track|>events_to_notes()|>notes_to_events()));
22        let merged = converted.merge_all().unwrap_items();
23        for e in merged {
24            if let Event::NoteOn(_) = *e {
25                nc += 1
26            }
27            track_writer.write_event(e).unwrap();
28        }
29    }
30
31    println!("Finished parsing midi, found {nc} notes");
32    println!("Elapsed {:?}", now.elapsed());
33    println!(
34        "Notes/second {}",
35        (nc as f64 / now.elapsed().as_secs_f64()).round()
36    );
37}
examples/events_notes.rs (line 22)
5pub fn main() {
6    println!("Opening midi...");
7    let file = MIDIFile::open("D:/Midis/tau2.5.9.mid", None).unwrap();
8    println!("Parsing midi...");
9    let now = Instant::now();
10    let mut nc: u64 = 0;
11    // for track in file.iter_all_tracks(true) {
12    //     // let track = TimeCaster::<f64>::cast_event_delta(track);
13    //     for e in pipe!(track|>unwrap_items())
14    //     // for e in pipe!(track|>TimeCaster::<f64>::cast_event_delta()|>scale_event_time(10.0)|>unwrap_items())
15    //     {
16    //         match e {
17    //             Event::NoteOn(_) => nc += 1,
18    //             _ => {}
19    //         }
20    //     }
21    // }
22    let merged = file.iter_all_tracks().merge_all().unwrap_items();
23
24    for e in merged {
25        if let Event::NoteOn(_) = *e {
26            nc += 1
27        }
28        let delta = e.delta;
29        if delta > 184467440737 {
30            dbg!(e);
31        }
32    }
33
34    println!("Finished parsing midi, found {nc} notes");
35    println!("Elapsed {:?}", now.elapsed());
36    println!(
37        "Notes/second {}",
38        (nc as f64 / now.elapsed().as_secs_f64()).round()
39    );
40}
examples/note_chopper.rs (line 48)
29fn main() {
30    let file = MIDIFile::open("D:/Midis/tau2.5.9.mid", None).unwrap();
31
32    let chop_size = file.ppq() as u64 / 16;
33
34    let writer = MIDIWriter::new("./out.mid", file.ppq()).unwrap();
35
36    for (i, track) in file.iter_all_tracks().enumerate() {
37        println!("Chopping track {} of {}", i, file.track_count());
38
39        let cached = track.collect_vec_result().unwrap();
40
41        let non_note_events = cached.iter().cloned().into_ok().filter_non_note_events();
42
43        let notes = cached
44            .iter()
45            .cloned()
46            .into_ok()
47            .events_to_notes()
48            .unwrap_items();
49        let chopped = notes.map(|n| chop_note(n, chop_size).into_ok());
50        let flattened = chopped.merge_all().notes_to_events();
51
52        // let notes = pipe!(cached.iter().cloned()|>wrap_ok()|>events_to_notes()|>unwrap_items());
53        // let flattened = pipe!(notes|>wrap_ok()|>notes_to_events());
54
55        let merged = merge_events(flattened, non_note_events);
56
57        writer
58            .try_open_next_track()
59            .unwrap()
60            .write_events_iter(merged.unwrap_items())
61            .unwrap();
62    }
63}
Source

fn collect_vec_result(self) -> Result<Vec<T>, Err>

Examples found in repository?
examples/note_chopper.rs (line 39)
29fn main() {
30    let file = MIDIFile::open("D:/Midis/tau2.5.9.mid", None).unwrap();
31
32    let chop_size = file.ppq() as u64 / 16;
33
34    let writer = MIDIWriter::new("./out.mid", file.ppq()).unwrap();
35
36    for (i, track) in file.iter_all_tracks().enumerate() {
37        println!("Chopping track {} of {}", i, file.track_count());
38
39        let cached = track.collect_vec_result().unwrap();
40
41        let non_note_events = cached.iter().cloned().into_ok().filter_non_note_events();
42
43        let notes = cached
44            .iter()
45            .cloned()
46            .into_ok()
47            .events_to_notes()
48            .unwrap_items();
49        let chopped = notes.map(|n| chop_note(n, chop_size).into_ok());
50        let flattened = chopped.merge_all().notes_to_events();
51
52        // let notes = pipe!(cached.iter().cloned()|>wrap_ok()|>events_to_notes()|>unwrap_items());
53        // let flattened = pipe!(notes|>wrap_ok()|>notes_to_events());
54
55        let merged = merge_events(flattened, non_note_events);
56
57        writer
58            .try_open_next_track()
59            .unwrap()
60            .write_events_iter(merged.unwrap_items())
61            .unwrap();
62    }
63}
More examples
Hide additional examples
examples/benchmark.rs (line 43)
32fn main() {
33    let filename = "D:/Midis/Ra Ra Rasputin Ultimate Black MIDI Final.mid";
34    let repeats = 4;
35
36    println!("Opening midi...");
37    let file = MIDIFile::open(filename, None).unwrap();
38
39    println!("Tracks: {}", file.track_count());
40
41    let loaded_tracks = file
42        .iter_all_tracks()
43        .map(|t| t.collect_vec_result().unwrap())
44        .collect::<Vec<_>>();
45
46    let mut nc: u64 = 0;
47    for track in loaded_tracks.iter() {
48        for e in track {
49            if let Event::NoteOn(_) = **e {
50                nc += 1
51            }
52        }
53    }
54    println!("Note count: {nc}");
55
56    do_run("Parse all tracks individually", repeats, || {
57        for track in file.iter_all_tracks() {
58            for _ in track {}
59        }
60    });
61    do_run("Merge all tracks together while parsing", repeats, || {
62        let merged = file.iter_all_tracks().merge_all();
63        for _ in merged {}
64    });
65    do_run("Clone all events", repeats, || {
66        let iters = loaded_tracks.iter().map(|t| t.iter().cloned());
67        for track in iters {
68            for _ in track {}
69        }
70    });
71    do_run(
72        "Clone all events, then wrap and unwrap them in Result",
73        repeats,
74        || {
75            let iters = loaded_tracks
76                .iter()
77                .map(|t| t.iter().cloned().into_ok().unwrap_items());
78            for track in iters {
79                for _ in track {}
80            }
81        },
82    );
83    do_run("Merge all tracks together while cloning", repeats, || {
84        let iters = loaded_tracks
85            .iter()
86            .map(|t| t.iter().cloned().into_ok())
87            .collect::<Vec<_>>();
88        let merged = iters.into_iter().merge_all();
89        for _ in merged {}
90    });
91    do_run("Write each track while cloning", repeats, || {
92        let output = Cursor::new(Vec::<u8>::new());
93        let writer = MIDIWriter::new_from_stream(Box::new(output), file.ppq()).unwrap();
94
95        let iters = loaded_tracks.iter().map(|t| t.iter().cloned());
96        for track in iters {
97            let mut track_writer = writer.try_open_next_track().unwrap();
98            for e in track {
99                track_writer.write_event(e).unwrap();
100            }
101        }
102    });
103    do_run("Merge each track while cloning then write", repeats, || {
104        let output = Cursor::new(Vec::<u8>::new());
105        let writer = MIDIWriter::new_from_stream(Box::new(output), file.ppq()).unwrap();
106
107        let iters = loaded_tracks
108            .iter()
109            .map(|t| t.iter().cloned().into_ok())
110            .collect::<Vec<_>>();
111        let merged = iters.into_iter().merge_all().unwrap_items();
112        let mut track_writer = writer.try_open_next_track().unwrap();
113        for e in merged {
114            track_writer.write_event(e).unwrap();
115        }
116    });
117}

Dyn Compatibility§

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors§

Source§

impl<T, Err, I> ResultIterExt<T, Err> for I
where I: Iterator<Item = Result<T, Err>> + Sized,