3 files changed, 112 insertions(+), 0 deletions(-)

A .gitignore
A Cargo.toml
A src/lib.rs

@@ 1,2 @@
+/target
+Cargo.lock

@@ 1,11 @@
+[package]
+name = "pdcm-linkify"
+version = "0.1.0"
+authors = ["Marcus Klaas <mail@marcusklaas.nl>", "Colin Reeder <vpzomtrrfrt@gmail.com>"]
+edition = "2015"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+pulldown-cmark = "0.8.0"
+regex = "1.4.2"

@@ 1,99 @@
+extern crate pulldown_cmark;
+extern crate regex;
+
+use pulldown_cmark::{CowStr, Event, LinkType, Tag};
+use regex::Regex;
+
+static URL_REGEX: &str = r#"((https?|ftp)://|www.)[^\s/$.?#].[^\s]*[^.^\s]"#;
+
+enum LinkState {
+    Open,
+    Label,
+    Close,
+}
+
+enum AutoLinkerState<'a> {
+    Clear,
+    Link(LinkState, CowStr<'a>, CowStr<'a>),
+    TrailingText(CowStr<'a>),
+}
+
+pub struct AutoLinker<'a, I> {
+    iter: I,
+    state: AutoLinkerState<'a>,
+    regex: Regex,
+}
+
+impl<'a, I> AutoLinker<'a, I> {
+    pub fn new(iter: I) -> Self {
+        Self {
+            iter,
+            state: AutoLinkerState::Clear,
+            regex: Regex::new(URL_REGEX).unwrap(),
+        }
+    }
+}
+
+impl<'a, I> Iterator for AutoLinker<'a, I>
+where
+    I: Iterator<Item = Event<'a>>,
+{
+    type Item = Event<'a>;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        let text = match std::mem::replace(&mut self.state, AutoLinkerState::Clear) {
+            AutoLinkerState::Clear => match self.iter.next() {
+                Some(Event::Text(text)) => text,
+                x => return x,
+            },
+            AutoLinkerState::TrailingText(text) => text,
+            AutoLinkerState::Link(link_state, link_text, trailing_text) => match link_state {
+                LinkState::Open => {
+                    self.state = AutoLinkerState::Link(
+                        LinkState::Label,
+                        link_text.clone(),
+                        trailing_text.clone(),
+                    );
+                    return Some(Event::Start(Tag::Link(
+                        LinkType::Inline,
+                        link_text,
+                        "".into(),
+                    )));
+                }
+                LinkState::Label => {
+                    self.state = AutoLinkerState::Link(
+                        LinkState::Close,
+                        link_text.clone(),
+                        trailing_text.clone(),
+                    );
+                    return Some(Event::Text(link_text));
+                }
+                LinkState::Close => {
+                    self.state = AutoLinkerState::TrailingText(trailing_text);
+                    return Some(Event::End(Tag::Link(
+                        LinkType::Inline,
+                        link_text,
+                        "".into(),
+                    )));
+                }
+            },
+        };
+
+        match self.regex.find(&text) {
+            Some(reg_match) => {
+                let link_text = reg_match.as_str();
+                let leading_text = &text.as_ref()[..reg_match.start()];
+                let trailing_text = &text.as_ref()[reg_match.end()..];
+
+                self.state = AutoLinkerState::Link(
+                    LinkState::Open,
+                    link_text.to_owned().into(),
+                    trailing_text.to_owned().into(),
+                );
+
+                Some(Event::Text(leading_text.to_owned().into()))
+            }
+            None => Some(Event::Text(text)),
+        }
+    }
+}