Add iterative search/replace example to examples and README.md

README.md

@@ -162,45 +162,38 @@ Or you can parse the input into an AST yourself, manipulate it, and then use you
 
 ``` rust
 extern crate comrak;
-use comrak::{parse_document, format_html, Arena, Options};
-use comrak::nodes::{AstNode, NodeValue};
-
-// The returned nodes are created in the supplied Arena, and are bound by its lifetime.
-let arena = Arena::new();
-
-let root = parse_document(
-    &arena,
-    "This is my input.\n\n1. Also my input.\n2. Certainly my input.\n",
-    &Options::default());
-
-fn iter_nodes<'a, F>(node: &'a AstNode<'a>, f: &F)
-    where F : Fn(&'a AstNode<'a>) {
-    f(node);
-    for c in node.children() {
-        iter_nodes(c, f);
-    }
-}
+use comrak::nodes::NodeValue;
+use comrak::{format_html, parse_document, Arena, Options};
+
+fn replace_text(document: &str, orig_string: &str, replacement: &str) -> String {
+    // The returned nodes are created in the supplied Arena, and are bound by its lifetime.
+    let arena = Arena::new();
 
-iter_nodes(root, &|node| {
-    match &mut node.data.borrow_mut().value {
-        &mut NodeValue::Text(ref mut text) => {
-            let orig = std::mem::replace(text, vec![]);
-            *text = String::from_utf8(orig).unwrap().replace("my", "your").as_bytes().to_vec();
+    // Parse the document into a root `AstNode`
+    let root = parse_document(&arena, document, &Options::default());
+
+    // Iterate over all the descendants of root.
+    for node in root.descendants() {
+        if let NodeValue::Text(ref mut text) = node.data.borrow_mut().value {
+            // If the node is a text node, perform the string replacement.
+            *text = text.replace(orig_string, replacement)
         }
-        _ => (),
     }
-});
-
-let mut html = vec![];
-format_html(root, &Options::default(), &mut html).unwrap();
-
-assert_eq!(
-    String::from_utf8(html).unwrap(),
-    "<p>This is your input.</p>\n\
-     <ol>\n\
-     <li>Also your input.</li>\n\
-     <li>Certainly your input.</li>\n\
-     </ol>\n");
+
+    let mut html = vec![];
+    format_html(root, &Options::default(), &mut html).unwrap();
+
+    String::from_utf8(html).unwrap()
+}
+
+fn main() {
+    let doc = "This is my input.\n\n1. Also [my](#) input.\n2. Certainly *my* input.\n";
+    let orig = "my";
+    let repl = "your";
+    let html = replace_text(&doc, &orig, &repl);
+
+    println!("{}", html);
+}
 ```
 
 ## Benchmarking

examples/iterator_replace.rs

@@ -0,0 +1,52 @@
+extern crate comrak;
+use comrak::nodes::NodeValue;
+use comrak::{format_html, parse_document, Arena, Options};
+use ntest::{assert_false, assert_true};
+
+fn replace_text(document: &str, orig_string: &str, replacement: &str) -> String {
+    // The returned nodes are created in the supplied Arena, and are bound by its lifetime.
+    let arena = Arena::new();
+
+    // Parse the document into a root `AstNode`
+    let root = parse_document(&arena, document, &Options::default());
+
+    // Iterate over all the descendants of root.
+    for node in root.descendants() {
+        if let NodeValue::Text(ref mut text) = node.data.borrow_mut().value {
+            // If the node is a text node, replace `orig_string` with `replacement`.
+            *text = text.replace(orig_string, replacement)
+        }
+    }
+
+    let mut html = vec![];
+    format_html(root, &Options::default(), &mut html).unwrap();
+
+    String::from_utf8(html).unwrap()
+}
+
+fn main() {
+    let doc = "This is my input.\n\n1. Also [my](#) input.\n2. Certainly *my* input.\n";
+    let orig = "my";
+    let repl = "your";
+    let html = replace_text(&doc, &orig, &repl);
+
+    println!("{}", html);
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn sample_replace() {
+        let doc = "Replace deeply nested *[foo](https://example.com)* with bar.\n\nReplace shallow foo with bar.";
+        let orig = "foo";
+        let repl = "bar";
+        let html = replace_text(&doc, &orig, &repl);
+        println!("{:?}", html);
+        assert_false!(html.contains("foo"));
+        assert_true!(html.contains("bar"));
+        assert_true!(html.contains("<a"));
+        assert_true!(html.contains("<p"));
+    }
+}