Make Parameters easier to populate

crates/fj-host/src/lib.rs

@@ -21,6 +21,7 @@ use std::{
     collections::{HashMap, HashSet},
     ffi::OsStr,
     io,
+    ops::{Deref, DerefMut},
     path::PathBuf,
     process::Command,
     sync::mpsc,
@@ -254,14 +255,40 @@ impl Watcher {
     }
 }
 
-/// Parameters that are passed to a model
+/// Parameters that are passed to a model.
+#[derive(Debug, Clone, PartialEq)]
 pub struct Parameters(pub HashMap<String, String>);
 
 impl Parameters {
     /// Construct an empty instance of `Parameters`
     pub fn empty() -> Self {
         Self(HashMap::new())
     }
+
+    /// Insert a value into the [`Parameters`] dictionary, implicitly converting
+    /// the arguments to strings and returning `&mut self` to enable chaining.
+    pub fn insert(
+        &mut self,
+        key: impl Into<String>,
+        value: impl Into<String>,
+    ) -> &mut Self {
+        self.0.insert(key.into(), value.into());
+        self
+    }
+}
+
+impl Deref for Parameters {
+    type Target = HashMap<String, String>;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl DerefMut for Parameters {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.0
+    }
 }
 
 /// An error that can occur when loading or reloading a model