added info about corpus concept

src/corpus/mod.rs

@@ -302,6 +302,55 @@ where
     }
 }
 
+/* TODO: Iterator corpus, like:
+
+enum MutationAction {
+    ReplaceInput(old_ref, new_val),
+    AppendNewInput(new_val),
+}
+
+struct NewCorpus {
+    testcases: Vec<NewTestCase>,
+    offset: usize;
+}
+
+impl NewCorpus {
+
+    pub fn handle_mutation(&mut self, action: MutationAction) {
+        match action {
+            MutationAction::ReplaceInput() => {},
+            MutationAction::AppendNewInput() => {},
+        }
+    }
+}
+
+impl Iterator for NewCorpus {
+    type Item = NewTestCase;
+
+    fn next(&mut self) -> Option<&Self::Item> {
+        // FIXME: implement next here
+        self.offset = 3;
+
+        // When no more stuff, return None
+        None
+    }
+}
+
+And then:
+
+    corpus.iter()
+        .mutate_foo()
+        .mutate_bar()
+        .set_observer(obs)
+        .execute_binary(|input| {
+            ...
+        })
+        .map(|observers, input, mutators| match result {
+            /// do things  depending on coverage, etc...
+            e.g. corpus.handle_mutation(MutationAction::AppendNewInput)
+        })
+*/
+
 #[cfg(test)]
 mod tests {
     use crate::corpus::Corpus;