Merge pull request #1 from pwoolcoc/page-iterator

Item Iter

src/entities/itemsiter.rs

@@ -0,0 +1,91 @@
+use page::Page;
+use serde::Deserialize;
+
+/// Abstracts away the `next_page` logic into a single stream of items
+///
+/// ```no_run
+/// # extern crate mammut;
+/// # use mammut::{Data, Mastodon};
+/// # use std::error::Error;
+/// # fn main() -> Result<(), Box<Error>> {
+/// # let data = Data {
+/// #   base: "".into(),
+/// #   client_id: "".into(),
+/// #   client_secret: "".into(),
+/// #   redirect: "".into(),
+/// #   token: "".into(),
+/// # };
+/// let client = Mastodon::from_data(data);
+/// let statuses = client.statuses("user-id", None)?;
+/// for status in statuses.items_iter() {
+///   // do something with `status`
+/// }
+/// # Ok(())
+/// # }
+/// ```
+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())
+        }
+    }
+}

src/entities/mod.rs

@@ -6,6 +6,7 @@ pub mod instance;
 pub mod list;
 pub mod mention;
 pub mod notification;
+pub(crate) mod itemsiter;
 pub mod relationship;
 pub mod report;
 pub mod search_result;

src/lib.rs

@@ -587,16 +587,42 @@ impl Mastodon {
     ///
     /// # Example
     ///
-    /// ```ignore
+    /// ```no_run
+    /// # extern crate mammut;
+    /// # use mammut::{Data, Mastodon};
+    /// # use std::error::Error;
+    /// # fn main() -> Result<(), Box<Error>> {
+    /// # let data = Data {
+    /// #   base: "".into(),
+    /// #   client_id: "".into(),
+    /// #   client_secret: "".into(),
+    /// #   redirect: "".into(),
+    /// #   token: "".into(),
+    /// # };
     /// let client = Mastodon::from_data(data);
     /// let statuses = client.statuses("user-id", None)?;
+    /// # Ok(())
+    /// # }
     /// ```
     ///
-    /// ```ignore
+    /// ```no_run
+    /// # extern crate mammut;
+    /// # use mammut::{Data, Mastodon, StatusesRequest};
+    /// # use std::error::Error;
+    /// # fn main() -> Result<(), Box<Error>> {
+    /// # let data = Data {
+    /// #   base: "".into(),
+    /// #   client_id: "".into(),
+    /// #   client_secret: "".into(),
+    /// #   redirect: "".into(),
+    /// #   token: "".into(),
+    /// # };
     /// let client = Mastodon::from_data(data);
     /// let request = StatusesRequest::default()
     ///                               .only_media();
     /// let statuses = client.statuses("user-id", request)?;
+    /// # Ok(())
+    /// # }
     /// ```
     pub fn statuses<'a, S>(&self, id: &str, request: S) -> Result<Page<Status>>
             where S: Into<Option<StatusesRequest<'a>>>

src/page.rs

@@ -3,6 +3,7 @@ use reqwest::Response;
 use reqwest::header::{Link, RelationType};
 use serde::Deserialize;
 use url::Url;
+use entities::itemsiter::ItemsIter;
 
 pub struct Page<'a, T: for<'de> Deserialize<'de>> {
     mastodon: &'a Mastodon,
@@ -53,6 +54,13 @@ impl<'a, T: for<'de> Deserialize<'de>> Page<'a, T> {
     }
 }
 
+impl<'a, T: Clone + for<'de> Deserialize<'de>> Page<'a, T> {
+    pub fn items_iter(self) -> impl Iterator<Item = T> + 'a
+            where T: 'a
+    {
+        ItemsIter::new(self)
+    }
+}
 
 fn get_links(response: &Response) -> Result<(Option<Url>, Option<Url>)> {
     let mut prev = None;