diff --git a/Cargo.toml b/Cargo.toml
index 382075918c..fb5a164439 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -18,3 +18,5 @@ spirv = { package = "spirv_headers", version = "1" }
 
 [dev-dependencies]
 env_logger = "0.6"
+ron = "0.5"
+serde = { version = "1", features = ["serde_derive"] }
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000000..d1240c235d
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,15 @@
+.PHONY: all clean
+
+all: boids.metallib
+
+clean:
+	rm *.metal *.air *.metallib
+
+%.metal: test-data/%.wgsl $(wildcard src/*.rs src/**/*.rs examples/*.rs)
+	cargo run --example convert -- $< $@
+
+%.air: %.metal
+	xcrun -sdk macosx metal -c $< -mmacosx-version-min=10.11
+
+%.metallib: %.air
+	xcrun -sdk macosx metallib $< -o $@
diff --git a/examples/convert.rs b/examples/convert.rs
index aa266e8892..f9aacd29b4 100644
--- a/examples/convert.rs
+++ b/examples/convert.rs
@@ -1,5 +1,24 @@
+use serde::{Serialize, Deserialize};
 use std::{env, fs};
 
+#[derive(Hash, PartialEq, Eq, Serialize, Deserialize)]
+struct BindSource {
+    set: u32,
+    binding: u32,
+}
+
+#[derive(Serialize, Deserialize)]
+struct BindTarget {
+    buffer: Option<u8>,
+    texture: Option<u8>,
+    sampler: Option<u8>,
+}
+
+#[derive(Default, Serialize, Deserialize)]
+struct Parameters {
+    metal_bindings: naga::FastHashMap<BindSource, BindTarget>,
+}
+
 fn main() {
     env_logger::init();
 
@@ -20,17 +39,32 @@ fn main() {
 
     if args.len() <= 2 {
         println!("{:#?}", module);
-    } else if args[2].ends_with(".metal") {
+        return;
+    }
+
+    let param_path = std::path::PathBuf::from(&args[1])
+        .with_extension("ron");
+    let params = match fs::read_to_string(param_path) {
+        Ok(string) => ron::de::from_str(&string).unwrap(),
+        Err(_) => Parameters::default(),
+    };
+
+    if args[2].ends_with(".metal") {
         use naga::back::msl;
         let mut binding_map = msl::BindingMap::default();
-        binding_map.insert(
-            msl::BindSource { set: 0, binding: 0 },
-            msl::BindTarget { buffer: None, texture: Some(1), sampler: None },
-        );
-        binding_map.insert(
-            msl::BindSource { set: 0, binding: 1 },
-            msl::BindTarget { buffer: None, texture: None, sampler: Some(1) },
-        );
+        for (key, value) in params.metal_bindings {
+            binding_map.insert(
+                msl::BindSource {
+                    set: key.set,
+                    binding: key.binding,
+                },
+                msl::BindTarget {
+                    buffer: value.buffer,
+                    texture: value.texture,
+                    sampler: value.sampler,
+                },
+            );
+        }
         let options = msl::Options {
             binding_map: &binding_map,
         };
diff --git a/src/lib.rs b/src/lib.rs
index 85f4fb7873..c1cf027b54 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -13,8 +13,8 @@ use std::{
 };
 
 
-type FastHashMap<K, T> = HashMap<K, T, BuildHasherDefault<fxhash::FxHasher>>;
-type FastHashSet<K> = HashSet<K, BuildHasherDefault<fxhash::FxHasher>>;
+pub type FastHashMap<K, T> = HashMap<K, T, BuildHasherDefault<fxhash::FxHasher>>;
+pub type FastHashSet<K> = HashSet<K, BuildHasherDefault<fxhash::FxHasher>>;
 
 #[derive(Clone, Debug)]
 pub struct Header {
diff --git a/test-data/boids.ron b/test-data/boids.ron
new file mode 100644
index 0000000000..1bf180ed2c
--- /dev/null
+++ b/test-data/boids.ron
@@ -0,0 +1,7 @@
+(
+	metal_bindings: {
+		(set: 0, binding: 0): (buffer: Some(0), texture: None, sampler: None),
+		(set: 0, binding: 1): (buffer: Some(1), texture: None, sampler: None),
+		(set: 0, binding: 2): (buffer: Some(2), texture: None, sampler: None),
+	}
+)
\ No newline at end of file
diff --git a/tests/convert.rs b/tests/convert.rs
index 9740e41549..fe86a7034f 100644
--- a/tests/convert.rs
+++ b/tests/convert.rs
@@ -30,7 +30,19 @@ fn convert_boids() {
     let module = load_wgsl("boids");
     {
         use naga::back::msl;
-        let binding_map = msl::BindingMap::default();
+        let mut binding_map = msl::BindingMap::default();
+        binding_map.insert(
+            msl::BindSource { set: 0, binding: 0 },
+            msl::BindTarget { buffer: Some(0), texture: None, sampler: None },
+        );
+        binding_map.insert(
+            msl::BindSource { set: 0, binding: 1 },
+            msl::BindTarget { buffer: Some(1), texture: None, sampler: Some(1) },
+        );
+        binding_map.insert(
+            msl::BindSource { set: 0, binding: 2 },
+            msl::BindTarget { buffer: Some(2), texture: None, sampler: Some(1) },
+        );
         let options = msl::Options {
             binding_map: &binding_map,
         };