Expose more mutability

src/ir/mod.rs

@@ -23,7 +23,8 @@ pub type LocalId = Id<Local>;
 #[derive(Clone, Debug, PartialEq, Eq, Hash)]
 pub struct Local {
     id: LocalId,
-    ty: ValType,
+    /// The type of this local
+    pub ty: ValType,
     /// A human-readable name for this local, often useful when debugging
     pub name: Option<String>,
 }

src/module/locals.rs

@@ -34,4 +34,9 @@ impl ModuleLocals {
     pub fn iter(&self) -> impl Iterator<Item = &Local> {
         self.arena.iter().map(|(_, f)| f)
     }
+
+    /// Get a mutable reference to this module's globals.
+    pub fn iter_mut(&mut self) -> impl Iterator<Item = &mut Local> {
+        self.arena.iter_mut().map(|(_, f)| f)
+    }
 }

src/ty.rs

@@ -117,6 +117,18 @@ impl Type {
         &*self.results
     }
 
+    /// Get the parameters to this function type.
+    #[inline]
+    pub fn params_mut(&mut self) -> &mut [ValType] {
+        &mut *self.params
+    }
+
+    /// Get the results of this function type.
+    #[inline]
+    pub fn results_mut(&mut self) -> &mut [ValType] {
+        &mut *self.results
+    }
+
     pub(crate) fn is_for_function_entry(&self) -> bool {
         self.is_for_function_entry
     }