Change PageIter to ItemsIter

src/entities/itemsiter.rs

@@ -0,0 +1,80 @@
+use page::Page;
+use serde::Deserialize;
+
+/// Abstracts away the `next_page` logic into a single stream of items
+///
+/// ```ignore
+/// # extern crate mammut
+/// # use mammut::Mastodon;
+/// let client = Mastodon::from_data(data);
+/// let statuses = client.statuses("user-id", None);
+/// for status in statuses.into_iter() {
+///   // do something with `status`
+/// }
+/// ```
+pub struct ItemsIter<'a, T: Clone + for<'de> Deserialize<'de>> {
+    page: Page<'a, T>,
+    buffer: Vec<T>,
+    cur_idx: usize,
+    use_initial: bool,
+}
+
+impl<'a, T: Clone + for<'de> Deserialize<'de>> ItemsIter<'a, T> {
+    pub(crate) fn new(page: Page<'a, T>) -> ItemsIter<'a, T> {
+        ItemsIter {
+            page: page,
+            buffer: vec![],
+            cur_idx: 0,
+            use_initial: true,
+        }
+    }
+
+    fn need_next_page(&self) -> bool {
+        self.buffer.is_empty() ||
+            self.cur_idx == self.buffer.len()
+    }
+
+    fn fill_next_page(&mut self) -> Option<()> {
+        let items = if let Ok(items) = self.page.next_page() {
+            items
+        } else {
+            return None;
+        };
+        if let Some(items) = items {
+            self.buffer = items;
+            self.cur_idx = 0;
+            Some(())
+        } else {
+            None
+        }
+    }
+}
+
+impl<'a, T: Clone+ for<'de> Deserialize<'de>> Iterator for ItemsIter<'a, T> {
+    type Item = T;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        if self.use_initial {
+            if self.page.initial_items.is_empty() {
+                return None;
+            }
+            let idx = self.cur_idx;
+            if self.cur_idx == self.page.initial_items.len() - 1 {
+                self.cur_idx = 0;
+                self.use_initial = false;
+            } else {
+                self.cur_idx += 1;
+            }
+            Some(self.page.initial_items[idx].clone())
+        } else {
+            if self.need_next_page() {
+                if self.fill_next_page().is_none() {
+                    return None;
+                }
+            }
+            let idx = self.cur_idx;
+            self.cur_idx += 1;
+            Some(self.buffer[idx].clone())
+        }
+    }
+}