openpgp: Streamline iteration over MessageStructure.

  - Implement IntoIter and Deref to &'a [MessageLayer<'a>], drop the
    custom iteration structs.

6 files changed, 24 insertions, 39 deletions

diff --git a/openpgp-ffi/examples/decrypt-with.c b/openpgp-ffi/examples/decrypt-with.c
index 8bdb2d9d..4519a2f1 100644
--- a/openpgp-ffi/examples/decrypt-with.c
+++ b/openpgp-ffi/examples/decrypt-with.c
@@ -41,7 +41,8 @@ get_certs_cb (void *cookie_raw,
 static pgp_status_t
 check_cb (void *cookie_opaque, pgp_message_structure_t structure)
 {
-  pgp_message_structure_iter_t iter = pgp_message_structure_iter (structure);
+  pgp_message_structure_iter_t iter =
+    pgp_message_structure_into_iter (structure);
 
   for (pgp_message_layer_t layer = pgp_message_structure_iter_next (iter);
        layer;
@@ -142,7 +143,6 @@ check_cb (void *cookie_opaque, pgp_message_structure_t structure)
   }
 
   pgp_message_structure_iter_free (iter);
-  pgp_message_structure_free (structure);
 
   /* Implement your verification policy here.  */
   return PGP_STATUS_SUCCESS;
diff --git a/openpgp-ffi/include/sequoia/openpgp.h b/openpgp-ffi/include/sequoia/openpgp.h
index d6a7b219..580134ee 100644
--- a/openpgp-ffi/include/sequoia/openpgp.h
+++ b/openpgp-ffi/include/sequoia/openpgp.h
@@ -1823,7 +1823,7 @@ void pgp_message_structure_free (pgp_message_structure_t);
 char *pgp_message_structure_debug (const pgp_message_structure_t);
 
 pgp_message_structure_iter_t
-pgp_message_structure_iter (pgp_message_structure_t);
+pgp_message_structure_into_iter (pgp_message_structure_t);
 
 /*/
 /// Frees this object.
diff --git a/openpgp-ffi/src/parse/stream.rs b/openpgp-ffi/src/parse/stream.rs
index 9e23cb47..da9d45c3 100644
--- a/openpgp-ffi/src/parse/stream.rs
+++ b/openpgp-ffi/src/parse/stream.rs
@@ -59,14 +59,15 @@ pub struct MessageStructure<'a>(stream::MessageStructure<'a>);
 
 /// Iterates over the message structure.
 #[::sequoia_ffi_macros::extern_fn] #[no_mangle] pub extern "C"
-fn pgp_message_structure_iter(structure: *const MessageStructure)
-                              -> *mut MessageStructureIter {
-    structure.ref_raw().iter().move_into_raw()
+fn pgp_message_structure_into_iter(structure: *mut MessageStructure)
+                                   -> *mut MessageStructureIter {
+    structure.move_from_raw().into_iter().move_into_raw()
 }
 
 /// Iterates over the message structure.
 #[crate::ffi_wrapper_type(prefix = "pgp_", derive = "Iterator(MessageLayer)")]
-pub struct MessageStructureIter<'a>(stream::MessageStructureIter<'a>);
+pub struct MessageStructureIter<'a>(
+    std::vec::IntoIter<stream::MessageLayer<'a>>);
 
 /// Represents a layer of the message structure.
 #[crate::ffi_wrapper_type(prefix = "pgp_", derive = "Debug")]
@@ -570,7 +571,7 @@ impl VerificationHelper for VHelper {
 /// check_cb (void *cookie_opaque, pgp_message_structure_t structure)
 /// {
 ///   pgp_message_structure_iter_t iter =
-///     pgp_message_structure_iter (structure);
+///     pgp_message_structure_into_iter (structure);
 ///   pgp_message_layer_t layer = pgp_message_structure_iter_next (iter);
 ///   assert (layer);
 ///   assert (pgp_message_layer_compression (layer, NULL));
@@ -591,7 +592,6 @@ impl VerificationHelper for VHelper {
 ///   pgp_verification_result_iter_free (results);
 ///   pgp_message_layer_free (layer);
 ///   pgp_message_structure_iter_free (iter);
-///   pgp_message_structure_free (structure);
 ///   return PGP_STATUS_SUCCESS;
 /// }
 ///
@@ -697,7 +697,7 @@ pub struct DetachedVerifier(openpgp::parse::stream::DetachedVerifier<'static, VH
 /// check_cb (void *cookie_opaque, pgp_message_structure_t structure)
 /// {
 ///   pgp_message_structure_iter_t iter =
-///     pgp_message_structure_iter (structure);
+///     pgp_message_structure_into_iter (structure);
 ///   pgp_message_layer_t layer = pgp_message_structure_iter_next (iter);
 ///   assert (layer);
 ///   pgp_verification_result_iter_t results;
@@ -714,7 +714,6 @@ pub struct DetachedVerifier(openpgp::parse::stream::DetachedVerifier<'static, VH
 ///   pgp_verification_result_iter_free (results);
 ///   pgp_message_layer_free (layer);
 ///   pgp_message_structure_iter_free (iter);
-///   pgp_message_structure_free (structure);
 ///   return PGP_STATUS_SUCCESS;
 /// }
 ///
@@ -932,13 +931,12 @@ impl DecryptionHelper for DHelper {
 /// check_cb (void *cookie_opaque, pgp_message_structure_t structure)
 /// {
 ///   pgp_message_structure_iter_t iter =
-///     pgp_message_structure_iter (structure);
+///     pgp_message_structure_into_iter (structure);
 ///   pgp_message_layer_t layer = pgp_message_structure_iter_next (iter);
 ///   assert (layer);
 ///   assert (pgp_message_layer_encryption (layer, NULL, NULL));
 ///   pgp_message_layer_free (layer);
 ///   pgp_message_structure_iter_free (iter);
-///   pgp_message_structure_free (structure);
 ///   return PGP_STATUS_SUCCESS;
 /// }
 ///
diff --git a/openpgp/src/parse/stream.rs b/openpgp/src/parse/stream.rs
index 383b883e..fb7d0cf2 100644
--- a/openpgp/src/parse/stream.rs
+++ b/openpgp/src/parse/stream.rs
@@ -282,35 +282,22 @@ impl<'a> MessageStructure<'a> {
             panic!("cannot push to encryption or compression layer");
         }
     }
-
-    /// Iterates over the message structure.
-    pub fn iter(&self) -> MessageStructureIter {
-        MessageStructureIter(self.0.iter())
-    }
-
-    /// Iterates over the message structure.
-    pub fn into_iter(self) -> impl Iterator<Item = MessageLayer<'a>> {
-        MessageStructureIntoIter(self.0.into_iter())
-    }
 }
 
-/// Iterates over the message structure.
-pub struct MessageStructureIter<'a>(::std::slice::Iter<'a, MessageLayer<'a>>);
+impl<'a> std::ops::Deref for MessageStructure<'a> {
+    type Target = [MessageLayer<'a>];
 
-impl<'a> Iterator for MessageStructureIter<'a> {
-    type Item = &'a MessageLayer<'a>;
-    fn next(&mut self) -> Option<Self::Item> {
-        self.0.next()
+    fn deref(&self) -> &Self::Target {
+        &self.0[..]
     }
 }
 
-/// Iterates over the message structure.
-struct MessageStructureIntoIter<'a>(::std::vec::IntoIter<MessageLayer<'a>>);
-
-impl<'a> Iterator for MessageStructureIntoIter<'a> {
+impl<'a> IntoIterator for MessageStructure<'a> {
     type Item = MessageLayer<'a>;
-    fn next(&mut self) -> Option<Self::Item> {
-        self.0.next()
+    type IntoIter = std::vec::IntoIter<MessageLayer<'a>>;
+
+    fn into_iter(self) -> Self::IntoIter {
+        self.0.into_iter()
     }
 }
 
@@ -1816,7 +1803,7 @@ mod test {
             }
 
             fn check(&mut self, structure: MessageStructure) -> Result<()> {
-                assert_eq!(structure.iter().count(), 2);
+                assert_eq!(structure.len(), 2);
                 for (i, layer) in structure.into_iter().enumerate() {
                     match layer {
                         MessageLayer::SignatureGroup { results } => {
diff --git a/openpgp/src/policy.rs b/openpgp/src/policy.rs
index af676a69..22eb32ed 100644
--- a/openpgp/src/policy.rs
+++ b/openpgp/src/policy.rs
@@ -1178,7 +1178,7 @@ mod test {
 
             fn check(&mut self, structure: MessageStructure) -> Result<()>
             {
-                for layer in structure.iter() {
+                for layer in structure {
                     match layer {
                         MessageLayer::SignatureGroup { ref results } =>
                             for result in results {
@@ -1643,7 +1643,7 @@ mod test {
 
             fn check(&mut self, structure: MessageStructure) -> Result<()>
             {
-                for layer in structure.iter() {
+                for layer in structure {
                     match layer {
                         MessageLayer::SignatureGroup { ref results } =>
                             for result in results {
diff --git a/tool/src/commands/mod.rs b/tool/src/commands/mod.rs
index b1de8fa8..08219286 100644
--- a/tool/src/commands/mod.rs
+++ b/tool/src/commands/mod.rs
@@ -357,7 +357,7 @@ impl<'a> VerificationHelper for VHelper<'a> {
     }
 
     fn check(&mut self, structure: MessageStructure) -> Result<()> {
-        for layer in structure.iter() {
+        for layer in structure {
             match layer {
                 MessageLayer::Compression { algo } =>
                     eprintln!("Compressed using {}", algo),