base for the iterator API

src/directive_reader.rs

@@ -0,0 +1,81 @@
+//! Directive Reader
+//! Reads directives from the given source.
+
+use std::io::{Read, Cursor, BufReader};
+
+use crate::directives::DirectiveType;
+
+pub fn read<T: Read>(source: T) -> DirectiveIter<T> {
+    let iter = DirectiveIter::new(source);
+    iter
+}
+
+pub fn read_str<T: Read>(source: &str) -> DirectiveIter<Cursor<&str>> {
+    let cursor = Cursor::new(source);
+    let iter: DirectiveIter<Cursor<&str>> = DirectiveIter::new(cursor);
+    // read(cursor)
+    iter
+}
+
+pub struct DirectiveIter<T: Read> {
+    // source: T,
+    reader: BufReader<T>
+}
+
+impl<T: Read> DirectiveIter<T> {
+    pub fn new(source: T) -> Self {
+        let reader = BufReader::new(source);
+
+        Self {
+            // source,
+            reader
+        }
+    }
+}
+
+impl<T: Read> Iterator for DirectiveIter<T> {
+    type Item = DirectiveType;
+
+    fn next(self: &mut DirectiveIter<T>) -> Option<Self::Item> {
+        // Read lines and recognise the directive.
+        // TODO: Read line.
+        // TODO: Recognise directive, if any.
+        // TODO: Read additional lines, if needed (like for Xact).
+        // TODO: Parse and return the directive.
+
+        // return Some(DirectiveType::Xact(Xact::default()))
+
+        // TODO: "Return None when complete";
+        return None
+    }
+}
+
+
+#[cfg(test)]
+mod tests {
+    use std::io::Cursor;
+
+    use crate::directive_reader::read_str;
+
+    use super::DirectiveIter;
+
+    fn basic_test() {
+        let content = "blah blah";
+        // let reader = DirectiveIter::new();
+
+        let output = read_str::<Cursor<&str>>(content);
+
+        todo!("incomplete");
+    }
+
+    // #[test]
+    fn iterator_test() {
+        let content = "blah blah";
+        //let iter = DirectiveIter::new();
+        let iter = read_str::<Cursor<&str>>(content);
+
+        for x in iter {
+            println!("Directive: {:?}", x);
+        }
+    }
+}

src/iterator.rs

@@ -1,5 +1,7 @@
 /*!
- * Implemetation of the parser that returns an iterator over the results
+ * Implemetation of the parser that returns an iterator over the results.
+ * 
+ * An example on how to use Iterators.
  */
 
 use crate::{directives::DirectiveType, xact::Xact};

src/lib.rs

@@ -44,6 +44,7 @@ pub mod amount;
 mod balance;
 pub mod commodity;
 mod directives;
+mod directive_reader;
 pub mod history;
 mod iterator;
 pub mod journal;