domain: add optional on_line callback

src/cli/switch.rs

@@ -51,6 +51,7 @@ pub fn execute(args: &Args) -> Result<(), Error> {
         content: &content,
         writer,
         sections: &args.sections,
+        on_line: None,
     })
     .map_err(Error::Switch)
 }

src/domain.rs

@@ -44,7 +44,7 @@ impl Section {
     }
 }
 
-struct SectionInfo {
+pub(crate) struct SectionInfo {
     enable_variable: bool,
     disable_variable: bool,
 }

src/domain/switch.rs

@@ -33,6 +33,8 @@ impl std::fmt::Display for Error {
 
 impl std::error::Error for Error {}
 
+pub type OnLineFn = Box<dyn Fn(Option<&SectionInfo>, &String)>;
+
 pub struct Request<'args, W>
 where
     W: Write,
@@ -40,6 +42,7 @@ where
     pub content: &'args str,
     pub writer: W,
     pub sections: &'args [String],
+    pub on_line: Option<OnLineFn>,
 }
 
 pub fn execute<W>(req: Request<W>) -> Result<(), Error>
@@ -54,14 +57,14 @@ where
         .map(|s| Section::parse(s.as_str()))
         .collect::<Vec<_>>();
 
-    let mut current_sections: Option<SectionInfo> = None;
+    let mut current_section: Option<SectionInfo> = None;
 
     for line in req.content.split_inclusive('\n') {
         let new_line = if is_section_end(line) {
-            current_sections = None;
+            current_section = None;
             line.to_string()
         } else if let Some(section_info) = line.strip_prefix("### ") {
-            current_sections = section_info.split_whitespace().next().map(|r| {
+            current_section = section_info.split_whitespace().next().map(|r| {
                 let current_sections = r.split(',').map(Section::parse).collect::<Vec<_>>();
                 SectionInfo {
                     enable_variable: should_enable_variable(&choose_sections, &current_sections),
@@ -69,7 +72,7 @@ where
                 }
             });
             line.to_string()
-        } else if let Some(section_info) = current_sections.as_ref() {
+        } else if let Some(section_info) = current_section.as_ref() {
             let trimmed_line = line.trim_start_matches(['#', ' ']);
             let is_var = is_variable(trimmed_line);
             if is_var && section_info.enable_variable {
@@ -86,6 +89,10 @@ where
         writer
             .write_all(new_line.as_bytes())
             .map_err(|_| Error::WriteData)?;
+
+        if let Some(on_line) = req.on_line.as_ref() {
+            on_line(current_section.as_ref(), &new_line);
+        }
     }
 
     writer.flush().map_err(|_| Error::WriteData)