feat: add tools module

Cargo.toml

@@ -13,5 +13,6 @@ keywords = ["orgmode","emacs","parser"]
 travis-ci = { repository = "PoiScript/orgize" }
 
 [dependencies]
+bytecount = "0.5.1"
 jetscii = "0.4.3"
 memchr = "2"

src/lib.rs

@@ -62,5 +62,6 @@ pub mod headline;
 mod lines;
 pub mod objects;
 mod parser;
+pub mod tools;
 
 pub use parser::{Event, Parser};

src/tools.rs

@@ -0,0 +1,44 @@
+use crate::elements::{fn_def, keyword, Key};
+use crate::headline::Headline;
+use memchr::memchr;
+
+type Headlines<'a> = Vec<Headline<'a>>;
+type Keywords<'a> = Vec<(Key<'a>, &'a str)>;
+type Footnotes<'a> = Vec<&'a str>;
+
+pub fn metadata(src: &str) -> (Headlines<'_>, Keywords<'_>, Footnotes<'_>) {
+    let mut headlines = Vec::new();
+    let mut keywords = Vec::new();
+    let mut footnotes = Vec::new();
+
+    for line in src.lines().filter(|l| !l.is_empty()) {
+        if line.starts_with('*') {
+            let level = memchr(b' ', line.as_bytes()).unwrap_or_else(|| line.len());
+            if line.as_bytes()[0..level].iter().all(|&c| c == b'*') {
+                headlines.push(Headline::parse(line).0)
+            }
+        } else if line.starts_with("#+") {
+            if let Some((key, value, _)) = keyword::parse(line) {
+                keywords.push((key, value))
+            }
+        } else if line.starts_with("[fn:") {
+            if let Some((label, _, _)) = fn_def::parse(line) {
+                footnotes.push(label)
+            }
+        }
+    }
+
+    (headlines, keywords, footnotes)
+}
+
+pub fn toc(src: &str) -> Headlines<'_> {
+    metadata(src).0
+}
+
+pub fn keywords(src: &str) -> Keywords<'_> {
+    metadata(src).1
+}
+
+pub fn fn_def(src: &str) -> Footnotes<'_> {
+    metadata(src).2
+}