minore: improve readability

Tuples are hard to understand

crates/sourcegen/src/lib.rs

@@ -43,6 +43,7 @@ pub fn list_files(dir: &Path) -> Vec<PathBuf> {
     res
 }
 
+#[derive(Clone)]
 pub struct CommentBlock {
     pub id: String,
     pub line: usize,
@@ -55,11 +56,10 @@ impl CommentBlock {
 
         let tag = format!("{}:", tag);
         let mut res = Vec::new();
-        for (line, mut block) in do_extract_comment_blocks(text, true) {
-            let first = block.remove(0);
+        for mut block in CommentBlock::do_extract(text, true) {
+            let first = block.contents.remove(0);
             if let Some(id) = first.strip_prefix(&tag) {
-                let id = id.trim().to_string();
-                let block = CommentBlock { id, line, contents: block };
+                block.id = id.trim().to_string();
                 res.push(block);
             }
         }
@@ -67,48 +67,40 @@ impl CommentBlock {
     }
 
     pub fn extract_untagged(text: &str) -> Vec<CommentBlock> {
+        CommentBlock::do_extract(text, false)
+    }
+
+    fn do_extract(text: &str, allow_blocks_with_empty_lines: bool) -> Vec<CommentBlock> {
         let mut res = Vec::new();
-        for (line, block) in do_extract_comment_blocks(text, false) {
-            let id = String::new();
-            let block = CommentBlock { id, line, contents: block };
-            res.push(block);
+
+        let prefix = "// ";
+        let lines = text.lines().map(str::trim_start);
+
+        let dummy_block = CommentBlock { id: String::new(), line: 0, contents: Vec::new() };
+        let mut block = dummy_block.clone();
+        for (line_num, line) in lines.enumerate() {
+            if line == "//" && allow_blocks_with_empty_lines {
+                block.contents.push(String::new());
+                continue;
+            }
+
+            let is_comment = line.starts_with(prefix);
+            if is_comment {
+                block.contents.push(line[prefix.len()..].to_string());
+            } else {
+                if !block.contents.is_empty() {
+                    res.push(mem::replace(&mut block, dummy_block.clone()));
+                }
+                block.line = line_num + 2;
+            }
+        }
+        if !block.contents.is_empty() {
+            res.push(block)
         }
         res
     }
 }
 
-fn do_extract_comment_blocks(
-    text: &str,
-    allow_blocks_with_empty_lines: bool,
-) -> Vec<(usize, Vec<String>)> {
-    let mut res = Vec::new();
-
-    let prefix = "// ";
-    let lines = text.lines().map(str::trim_start);
-
-    let mut block = (0, vec![]);
-    for (line_num, line) in lines.enumerate() {
-        if line == "//" && allow_blocks_with_empty_lines {
-            block.1.push(String::new());
-            continue;
-        }
-
-        let is_comment = line.starts_with(prefix);
-        if is_comment {
-            block.1.push(line[prefix.len()..].to_string());
-        } else {
-            if !block.1.is_empty() {
-                res.push(mem::take(&mut block));
-            }
-            block.0 = line_num + 2;
-        }
-    }
-    if !block.1.is_empty() {
-        res.push(block)
-    }
-    res
-}
-
 #[derive(Debug)]
 pub struct Location {
     pub file: PathBuf,