Implement link extractor

libimagentrymarkdown/src/link.rs

@@ -1,8 +1,80 @@
 use result::Result;
 
-pub type Link = String;
+use hoedown::renderer::Render;
+use hoedown::Buffer;
+use hoedown::Markdown;
+
+pub struct Link {
+    pub title: String,
+    pub link: String,
+}
+
+struct LinkExtractor {
+    links: Vec<Link>,
+}
+
+impl LinkExtractor {
+
+    pub fn new() -> LinkExtractor {
+        LinkExtractor { links: vec![] }
+    }
+
+    pub fn links(self) -> Vec<Link> {
+        self.links
+    }
+
+}
+
+impl Render for LinkExtractor {
+
+    fn link(&mut self,
+            _: &mut Buffer,
+            content: Option<&Buffer>,
+            link: Option<&Buffer>,
+            _: Option<&Buffer>)
+        -> bool
+    {
+        let link  = link.and_then(|l| l.to_str().ok()).map(String::from);
+        let content = content.and_then(|l| l.to_str().ok()).map(String::from);
+
+        match (link, content) {
+            (Some(link), Some(content)) => {
+                self.links.push(Link { link: link, title: content });
+                false
+            },
+
+            (_, _) => {
+                false
+            },
+        }
+
+    }
+
+}
+
+pub fn extract_links(buf: &str) -> Vec<Link> {
+    let mut le = LinkExtractor::new();
+    le.render(&Markdown::new(buf));
+    le.links()
+}
+
+#[cfg(test)]
+mod test {
+    use super::{Link, extract_links};
+
+    #[test]
+    fn test_one_link() {
+        let testtext = "Some [example text](http://example.com).";
+
+        let exp = Link {
+            title: String::from("example text"),
+            link:  String::from("http://example.com"),
+        };
+
+        let mut links = extract_links(testtext);
+        assert_eq!(1, links.len());
+        assert_eq!(exp, links.pop().unwrap())
+    }
 
-pub fn extract_links(buf: &str) -> Result<Vec<Link>> {
-    unimplemented!()
 }