From 28454a4efcd69797b08fddc5f728ed77631e0c91 Mon Sep 17 00:00:00 2001
From: Dan Gohman <sunfish@mozilla.com>
Date: Thu, 16 Apr 2020 16:44:08 -0700
Subject: [PATCH] Use `ExactSizeIterator` to avoid needing separate `num_*`
 methods.

---
 crates/api/src/instance.rs |  6 +++---
 crates/api/src/module.rs   | 20 +++++---------------
 2 files changed, 8 insertions(+), 18 deletions(-)

diff --git a/crates/api/src/instance.rs b/crates/api/src/instance.rs
index 7be541658cea..d45177745f96 100644
--- a/crates/api/src/instance.rs
+++ b/crates/api/src/instance.rs
@@ -126,11 +126,11 @@ impl Instance {
             }
         }
 
-        if imports.len() != module.num_imports() {
+        if imports.len() != module.imports().len() {
             bail!(
                 "wrong number of imports provided, {} != {}",
                 imports.len(),
-                module.num_imports()
+                module.imports().len()
             );
         }
 
@@ -164,7 +164,7 @@ impl Instance {
     /// information about the export itself. The list returned here maps 1:1 with
     /// the list that [`Module::exports`] returns, and [`ExportType`](crate::ExportType)
     /// contains the name of each export.
-    pub fn exports<'me>(&'me self) -> impl Iterator<Item = Export> + 'me {
+    pub fn exports<'me>(&'me self) -> impl ExactSizeIterator<Item = Export> + 'me {
         let instance_handle = &self.instance_handle;
         let store = self.module.store();
         self.instance_handle
diff --git a/crates/api/src/module.rs b/crates/api/src/module.rs
index 0f55f0b4ee7f..b417f3cfcd16 100644
--- a/crates/api/src/module.rs
+++ b/crates/api/src/module.rs
@@ -376,7 +376,7 @@ impl Module {
     /// # fn main() -> anyhow::Result<()> {
     /// # let store = Store::default();
     /// let module = Module::new(&store, "(module)")?;
-    /// assert_eq!(module.num_imports(), 0);
+    /// assert_eq!(module.imports().len(), 0);
     /// # Ok(())
     /// # }
     /// ```
@@ -393,7 +393,7 @@ impl Module {
     ///     )
     /// "#;
     /// let module = Module::new(&store, wat)?;
-    /// assert_eq!(module.num_imports(), 1);
+    /// assert_eq!(module.imports().len(), 1);
     /// let import = module.imports().next().unwrap();
     /// assert_eq!(import.module, "host");
     /// assert_eq!(import.name, "foo");
@@ -404,7 +404,7 @@ impl Module {
     /// # Ok(())
     /// # }
     /// ```
-    pub fn imports<'me>(&'me self) -> impl Iterator<Item = ImportType> + 'me {
+    pub fn imports<'me>(&'me self) -> impl ExactSizeIterator<Item = ImportType> + 'me {
         let module = self.inner.compiled.module_ref();
         module
             .imports
@@ -419,11 +419,6 @@ impl Module {
             })
     }
 
-    /// Return the number of imports in this module.
-    pub fn num_imports(&self) -> usize {
-        self.inner.compiled.module_ref().imports.len()
-    }
-
     /// Returns the list of exports that this [`Module`] has and will be
     /// available after instantiation.
     ///
@@ -459,7 +454,7 @@ impl Module {
     ///     )
     /// "#;
     /// let module = Module::new(&store, wat)?;
-    /// assert_eq!(module.num_exports(), 2);
+    /// assert_eq!(module.exports().len(), 2);
     ///
     /// let foo = module.exports().next().unwrap();
     /// assert_eq!(foo.name, "foo");
@@ -477,7 +472,7 @@ impl Module {
     /// # Ok(())
     /// # }
     /// ```
-    pub fn exports<'me>(&'me self) -> impl Iterator<Item = ExportType> + 'me {
+    pub fn exports<'me>(&'me self) -> impl ExactSizeIterator<Item = ExportType> + 'me {
         let module = self.inner.compiled.module_ref();
         module.exports.iter().map(move |(name, entity_index)| {
             let r#type = entity_type(entity_index, module);
@@ -488,11 +483,6 @@ impl Module {
         })
     }
 
-    /// Return the number of exports in this module.
-    pub fn num_exports(&self) -> usize {
-        self.inner.compiled.module_ref().exports.len()
-    }
-
     /// Returns the [`Store`] that this [`Module`] was compiled into.
     pub fn store(&self) -> &Store {
         &self.inner.store