Parse single map definitions

Parse a map definition line into a `Map`.

Got so stuck on this error:

    error[E0277]: the trait bound `(): combine::Parser` is not satisfied
       --> src/lib.rs:107:16
        |
    107 | fn map<I>() -> impl Parser<Input = I, Output = Map>
        |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `combine::Parser` is not implemented for `()`
        |
        = note: the return type of a function must have a statically known size

    error: aborting due to previous error

    For more information about this error, try `rustc --explain E0277`.

Turns out the problem was that I had put a semicolon at the end of the
expression in `map()`. Geez. Took hours to finally see that.

1 files changed, 35 insertions, 0 deletions

diff --git a/src/lib.rs b/src/lib.rs
index 79941d1..5dbf477 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -35,6 +35,7 @@ pub struct MapAction {
     pub kind: MapKind,
 }
 
+#[derive(Debug, PartialEq)]
 struct Map {
     trigger: Trigger,
     action: Action,
@@ -103,6 +104,26 @@ where
     skip_many1(space().or(tab()))
 }
 
+fn map<I>() -> impl Parser<Input = I, Output = Map>
+where
+    I: Stream<Item = char>,
+    I::Error: ParseError<I::Item, I::Range, I::Position>,
+{
+    (
+        map_kind(),
+        whitespace_separator(),
+        trigger(),
+        whitespace_separator(),
+        action()
+    ).map(|(kind, _, trigger, _, action)|
+        Map {
+            trigger: trigger,
+            action: action,
+            kind: kind,
+        }
+    )
+}
+
 fn map_collection<I>() -> impl Parser<Input = I, Output = MapCollection>
 where
     I: Stream<Item = char>,
@@ -196,6 +217,20 @@ mod tests {
     }
 
     #[test]
+    fn map_parses_map_line() {
+        let text = "map <play><down> test
+";
+        let expected = Map {
+            trigger: vec![HeadphoneButton::Play, HeadphoneButton::Down],
+            action: "test".to_owned(),
+            kind: MapKind::Map,
+        };
+        let result = map().parse(text).map(|t| t.0);
+
+        assert_eq!(result, Ok(expected));
+    }
+
+    #[test]
     fn map_collection_parses_maps() {
         let text = "
 map <up><down> test