support regex attrs

Cargo.toml

@@ -13,6 +13,7 @@ repository = "https://github.com/utkarshkukreti/select.rs"
 bit-set = "0.5"
 html5ever = "0.25"
 markup5ever_rcdom = "0.1"
+regex = "1.3.9"
 
 [dev-dependencies]
 speculate = "0.1.2"

src/lib.rs

@@ -1,3 +1,5 @@
+extern crate regex;
+
 pub mod document;
 pub mod node;
 pub mod predicate;

src/predicate.rs

@@ -1,4 +1,5 @@
 use crate::node::{self, Node};
+use regex::Regex;
 
 /// A trait implemented by all `Node` matchers.
 pub trait Predicate {
@@ -94,6 +95,16 @@ impl<'a> Predicate for Attr<&'a str, ()> {
     }
 }
 
+impl<'a> Predicate for Attr<&'a str, Regex> {
+    fn matches(&self, node: &Node) -> bool {
+        if let Some(attr) = node.attr(self.0) {
+            return self.1.is_match(attr)
+        }
+        false
+    }
+}
+
+
 /// Matches if the function returns true.
 impl<F: Fn(&Node) -> bool> Predicate for F {
     fn matches(&self, node: &Node) -> bool {

tests/predicate_tests.rs

@@ -70,6 +70,9 @@ speculate! {
             assert_eq!(Attr("id", "post-0").matches(&article), true);
             assert_eq!(Attr("id", ()).matches(&html), false);
             assert_eq!(Attr("id", ()).matches(&article), true);
+            assert_eq!(Attr("id", regex::Regex::new("post").unwrap()).matches(&article), true);
+            assert_eq!(Attr("class", regex::Regex::new("^category$").unwrap()).matches(&article), false);
+            assert_eq!(Attr("class", regex::Regex::new("category").unwrap()).matches(&article), true);
         }
 
         test "Fn(&Node) -> bool" {