Add regexes module in moz_readability that contains the regular

expressions used. For optimal performance, the regular expresions
are compiled to static values to prevent recompiling in loops

src/main.rs

@@ -1,3 +1,6 @@
+#[macro_use]
+extern crate lazy_static;
+
 use std::fs::File;
 
 use async_std::{fs::create_dir, fs::remove_dir_all, task};

src/moz_readability/mod.rs

@@ -17,6 +17,7 @@ const PHRASING_ELEMS: [&str; 39] = [
     "output", "progress", "q", "ruby", "samp", "script", "select", "small", "span", "strong",
     "sub", "sup", "textarea", "time", "var", "wbr",
 ];
+mod regexes;
 
 pub struct Readability {
     root_node: NodeRef,

src/moz_readability/regexes.rs

@@ -0,0 +1,97 @@
+/// This module contains regular expressions frequently used by moz_readability
+/// All regexes that only test if a `&str` matches the regex are preceded by the
+/// word "is_match". All other regexes are publicly accessible.
+use regex::Regex;
+pub fn is_match_byline(match_str: &str) -> bool {
+    lazy_static! {
+        static ref BYLINE_REGEX: Regex =
+            Regex::new(r"(?i)byline|author|dateline|writtenby|p-author").unwrap();
+    }
+    BYLINE_REGEX.is_match(match_str)
+}
+
+pub fn is_match_positive(match_str: &str) -> bool {
+    lazy_static! {
+        static ref POSITIVE_REGEX: Regex = Regex::new(r"(?i)article|body|content|entry|hentry|h-entry|main|page|pagination|post|text|blog|story").unwrap();
+    }
+    POSITIVE_REGEX.is_match(match_str)
+}
+
+pub fn is_match_negative(match_str: &str) -> bool {
+    lazy_static! {
+        static ref NEGATIVE_REGEX: Regex = Regex::new(r"(?i)hidden|^hid$| hid$| hid |^hid |banner|combx|comment|com-|contact|foot|footer|footnote|gdpr|masthead|media|meta|outbrain|promo|related|scroll|share|shoutbox|sidebar|skyscraper|sponsor|shopping|tags|tool|widget").unwrap();
+    }
+    NEGATIVE_REGEX.is_match(match_str)
+}
+
+pub fn is_match_videos(match_str: &str) -> bool {
+    lazy_static! {
+        static ref VIDEOS_REGEX: Regex = Regex::new(r"(?i)//(www\.)?((dailymotion|youtube|youtube-nocookie|player\.vimeo|v\.qq)\.com|(archive|upload\.wikimedia)\.org|player\.twitch\.tv)").unwrap();
+    }
+    VIDEOS_REGEX.is_match(match_str)
+}
+
+pub fn is_match_unlikely(match_str: &str) -> bool {
+    lazy_static! {
+        static ref UNLIKELY_REGEX: Regex = Regex::new(r"(?i)-ad-|ai2html|banner|breadcrumbs|combx|comment|community|cover-wrap|disqus|extra|footer|gdpr|header|legends|menu|related|remark|replies|rss|shoutbox|sidebar|skyscraper|social|sponsor|supplemental|ad-break|agegate|pagination|pager|popup|yom-remote").unwrap();
+    }
+    UNLIKELY_REGEX.is_match(match_str)
+}
+
+pub fn is_match_ok_maybe(match_str: &str) -> bool {
+    lazy_static! {
+        static ref OK_MAYBE_REGEX: Regex =
+            Regex::new(r"(?i)and|article|body|column|content|main|shadow").unwrap();
+    }
+    OK_MAYBE_REGEX.is_match(match_str)
+}
+
+pub fn is_match_node_content(match_str: &str) -> bool {
+    lazy_static! {
+        static ref NODE_CONTENT_REGEX: Regex = Regex::new(r"\.( |$)").unwrap();
+    }
+    NODE_CONTENT_REGEX.is_match(match_str)
+}
+
+pub fn is_match_share_elems(match_str: &str) -> bool {
+    lazy_static! {
+        static ref SHARE_ELEMS_REGEX: Regex =
+            Regex::new(r"(?i)(\b|_)(share|sharedaddy)(\b|_)").unwrap();
+    }
+    SHARE_ELEMS_REGEX.is_match(match_str)
+}
+
+pub fn is_match_has_content(match_str: &str) -> bool {
+    lazy_static! {
+        static ref HAS_CONTENT_REGEX: Regex = Regex::new(r"\S$").unwrap();
+    }
+    HAS_CONTENT_REGEX.is_match(match_str)
+}
+
+pub fn is_match_img_ext(match_str: &str) -> bool {
+    lazy_static! {
+        static ref IMG_EXT_REGEX: Regex = Regex::new(r"(?i)\.(jpg|jpeg|png|webp)").unwrap();
+    }
+    IMG_EXT_REGEX.is_match(match_str)
+}
+
+pub fn is_match_srcset(match_str: &str) -> bool {
+    lazy_static! {
+        static ref SRCSET_REGEX: Regex = Regex::new(r"\.(jpg|jpeg|png|webp)\s+\d").unwrap();
+    }
+    SRCSET_REGEX.is_match(match_str)
+}
+
+pub fn is_match_src_regex(match_str: &str) -> bool {
+    lazy_static! {
+        static ref SRC_REGEX: Regex = Regex::new(r"^\s*\S+\.(jpg|jpeg|png|webp)\S*\s*$").unwrap();
+    }
+    SRC_REGEX.is_match(match_str)
+}
+
+lazy_static! {
+    pub static ref NORMALIZE_REGEX: Regex = Regex::new(r"\s{2,}").unwrap();
+    pub static ref B64_DATA_URL_REGEX: Regex =
+        Regex::new(r"(?i)^data:\s*([^\s;,]+)\s*;\s*base64\s*").unwrap();
+    pub static ref BASE64_REGEX: Regex = Regex::new(r"(?i)base64\s*").unwrap();
+}