cocoa_bridge: Continue outline of Objective C callable

Add some more structure to the function that will be called from
Objective C code.

* Give it a name, `parse_mappings` (not very thoroughly considered)
* Initialise some Foundation data structures to mirror our Rust ones
* Add the beginning of a struct that will be the ObjC version of our
  `MapGroup` struct, containing `NSDictionary`ies.
* Move the `extern crate` into `lib.rs`, I keep forgetting that's where
  they go.
* Add a test that just calls `parse_mappings` to check that the code
  compiles.

parser::MapGroup:
Make both its fields public to enable us to access them from
`cocoa_bridge`.

Used this helpful example as a reference for the Rust Cocoa code:
https://github.com/servo/core-foundation-rs/blob/c99c05c/cocoa/examples/hello_world.rs

3 files changed, 33 insertions, 5 deletions

diff --git a/src/cocoa_bridge.rs b/src/cocoa_bridge.rs
index 58d74d2..ea88661 100644
--- a/src/cocoa_bridge.rs
+++ b/src/cocoa_bridge.rs
@@ -1,13 +1,39 @@
-extern crate cocoa;
+use cocoa::base::nil;
+use cocoa::foundation::{NSArray, NSAutoreleasePool, NSDictionary};
 
 use MapGroup;
 
-pub extern "C" fn x() {
+#[repr(C)]
+struct renameMeMapGroup {
+}
+
+pub extern "C" fn parse_mappings() {
     let sample_maps = "map <up> k
 map <down> j";
 
-    let map_group = MapGroup::parse(sample_maps);
+    let map_group = MapGroup::parse(sample_maps).unwrap();
 
     unsafe {
+        let _pool = NSAutoreleasePool::new(nil);
+
+        let maps = NSDictionary::init(nil).autorelease();
+        let modes = NSDictionary::init(nil).autorelease();
+
+        for (trigger, action) in map_group.maps {
+            let t = NSArray::array(nil).autorelease();
+        }
+
+        for (trigger, modes) in map_group.modes {
+        }
+    }
+}
+
+
+mod tests {
+    use super::*;
+
+    #[test]
+    fn parse_mappings_makes_cocoa_mappings() {
+        parse_mappings();
     }
 }
diff --git a/src/lib.rs b/src/lib.rs
index c2d2f9f..e6260ed 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,3 +1,5 @@
+extern crate cocoa;
+
 #[macro_use]
 extern crate combine;
 
diff --git a/src/parser.rs b/src/parser.rs
index a34edff..d5cd860 100644
--- a/src/parser.rs
+++ b/src/parser.rs
@@ -51,8 +51,8 @@ struct Mode {
 
 #[derive(Debug, PartialEq)]
 pub struct MapGroup {
-    maps: MapCollection,
-    modes: HashMap<Trigger, MapCollection>,
+    pub maps: MapCollection,
+    pub modes: HashMap<Trigger, MapCollection>,
 }
 
 #[derive(Debug, PartialEq)]