docs: Add Rustdoc comments for info and mcp modules and grep plugin

Co-authored-by: aider (openai/andrew/openrouter/sonoma-sky-alpha) <aider@aider.chat>

src/filter_plugin/grep.rs

@@ -4,22 +4,39 @@ use regex::Regex;
 
 /// A filter that matches lines against a regular expression pattern.
 ///
-/// Outputs only lines that match the given regex.
+/// Outputs only lines that match the given regex. Uses BufRead for line-by-line processing
+/// and preserves original line endings.
+///
+/// # Fields
+///
+/// * `regex` - Compiled regex for matching.
 #[derive(Debug, Clone)]
 pub struct GrepFilter {
     regex: Regex,
 }
 
+/// Creates a new `GrepFilter` with the specified regex pattern.
+///
+/// Compiles the pattern using regex crate.
+///
+/// # Arguments
+///
+/// * `pattern` - The regular expression pattern (string) used to match lines.
+///
+/// # Returns
+///
+/// `Ok(Self)` on success.
+///
+/// # Errors
+///
+/// Returns `Err(io::Error::InvalidInput)` if pattern compilation fails (invalid regex).
+///
+/// # Examples
+///
+/// ```
+/// let filter = GrepFilter::new("error|warn".to_string())?;
+/// ```
 impl GrepFilter {
-    /// Creates a new `GrepFilter` with the specified regex pattern.
-    ///
-    /// # Arguments
-    ///
-    /// * `pattern` - The regular expression pattern used to match lines.
-    ///
-    /// # Errors
-    ///
-    /// Returns an `io::Error` with `InvalidInput` if the regex pattern is invalid.
     pub fn new(pattern: String) -> Result<Self> {
         let regex = Regex::new(&pattern)
             .map_err(|e| std::io::Error::new(std::io::ErrorKind::InvalidInput, e))?;
@@ -29,23 +46,30 @@ impl GrepFilter {
     }
 }
 
+/// Filters the input by writing only lines that match the regex pattern.
+///
+/// Reads lines from the input and writes matching lines to the output, preserving newlines.
+/// Uses BufReader for efficient line iteration.
+///
+/// # Arguments
+///
+/// * `reader` - A boxed mutable reference to the input reader providing the data stream.
+/// * `writer` - A boxed mutable reference to the output writer where matching lines are sent.
+///
+/// # Returns
+///
+/// `Ok(())` on success.
+///
+/// # Errors
+///
+/// Propagates `io::Error` from BufRead lines() or writeln! (e.g., read/write failures, UTF-8 issues).
+///
+/// # Examples
+///
+/// ```
+/// filter.filter(Box::new(&mut input), Box::new(&mut output))?;
+/// ```
 impl FilterPlugin for GrepFilter {
-    /// Filters the input by writing only lines that match the regex pattern.
-    ///
-    /// Reads lines from the input and writes matching lines to the output, preserving newlines.
-    ///
-    /// # Arguments
-    ///
-    /// * `reader` - A boxed mutable reference to the input reader providing the data stream.
-    /// * `writer` - A boxed mutable reference to the output writer where matching lines are sent.
-    ///
-    /// # Returns
-    ///
-    /// Returns `Ok(())` on success, or an `io::Error` if reading or writing fails.
-    ///
-    /// # Errors
-    ///
-    /// Propagates `io::Error` from reading lines or writing output.
     fn filter(&mut self, mut reader: Box<&mut dyn Read>, mut writer: Box<&mut dyn Write>) -> Result<()> {
         let mut buf_reader = std::io::BufReader::new(&mut *reader);
         for line in buf_reader.by_ref().lines() {
@@ -58,12 +82,18 @@ impl FilterPlugin for GrepFilter {
     }
 
     /// Clones this filter into a new boxed instance.
-    ///
-    /// Creates a new GrepFilter with the same regex pattern.
-    ///
-    /// # Returns
-    ///
-    /// A new `Box<dyn FilterPlugin>` representing a clone of this filter.
+///
+/// Creates a new GrepFilter with the same regex pattern.
+///
+/// # Returns
+///
+/// A new `Box<dyn FilterPlugin>` representing a clone of this filter.
+///
+/// # Examples
+///
+/// ```
+/// let cloned = filter.clone_box();
+/// ```
     fn clone_box(&self) -> Box<dyn FilterPlugin> {
         Box::new(Self {
             regex: self.regex.clone(),
@@ -71,12 +101,20 @@ impl FilterPlugin for GrepFilter {
     }
     
     /// Returns the configuration options for this filter.
-    ///
-    /// The only option is the required "pattern" for the regex.
-    ///
-    /// # Returns
-    ///
-    /// A vector of `FilterOption` describing the filter's configurable parameters.
+///
+/// The only option is the required "pattern" for the regex.
+///
+/// # Returns
+///
+/// A vector containing one `FilterOption` for "pattern" (required, no default).
+///
+/// # Examples
+///
+/// ```
+/// let opts = filter.options();
+/// assert_eq!(opts.len(), 1);
+/// assert!(opts[0].required);
+/// ```
     fn options(&self) -> Vec<FilterOption> {
         vec![
             FilterOption {