Move block comment helps to its own module

Author: tesuji

compiler/rustc_ast/src/util/comments.rs

@@ -1,6 +1,7 @@
 use rustc_span::source_map::SourceMap;
 use rustc_span::{BytePos, CharPos, FileName, Pos, Symbol};
 
+mod block_comment;
 #[cfg(test)]
 mod tests;
 
@@ -26,66 +27,7 @@ pub struct Comment {
 /// Makes a doc string more presentable to users.
 /// Used by rustdoc and perhaps other tools, but not by rustc.
 pub fn beautify_doc_string(data: Symbol) -> String {
-    /// remove whitespace-only lines from the start/end of lines
-    fn vertical_trim(lines: Vec<String>) -> Vec<String> {
-        let mut i = 0;
-        let mut j = lines.len();
-        // first line of all-stars should be omitted
-        if !lines.is_empty() && lines[0].chars().all(|c| c == '*') {
-            i += 1;
-        }
-
-        while i < j && lines[i].trim().is_empty() {
-            i += 1;
-        }
-        // like the first, a last line of all stars should be omitted
-        if j > i && lines[j - 1].chars().skip(1).all(|c| c == '*') {
-            j -= 1;
-        }
-
-        while j > i && lines[j - 1].trim().is_empty() {
-            j -= 1;
-        }
-
-        lines[i..j].to_vec()
-    }
-
-    /// remove a "[ \t]*\*" block from each line, if possible
-    fn horizontal_trim(lines: Vec<String>) -> Vec<String> {
-        let mut i = usize::MAX;
-        let mut can_trim = true;
-        let mut first = true;
-
-        for line in &lines {
-            for (j, c) in line.chars().enumerate() {
-                if j > i || !"* \t".contains(c) {
-                    can_trim = false;
-                    break;
-                }
-                if c == '*' {
-                    if first {
-                        i = j;
-                        first = false;
-                    } else if i != j {
-                        can_trim = false;
-                    }
-                    break;
-                }
-            }
-            if i >= line.len() {
-                can_trim = false;
-            }
-            if !can_trim {
-                break;
-            }
-        }
-
-        if can_trim {
-            lines.iter().map(|line| (&line[i + 1..line.len()]).to_string()).collect()
-        } else {
-            lines
-        }
-    }
+    use block_comment::{horizontal_trim, vertical_trim};
 
     let data = data.as_str();
     if data.contains('\n') {

compiler/rustc_ast/src/util/comments/block_comment.rs

@@ -0,0 +1,64 @@
+/*!
+ * Block comment helpers.
+ */
+
+/// remove whitespace-only lines from the start/end of lines
+pub fn vertical_trim(lines: Vec<String>) -> Vec<String> {
+    let mut i = 0;
+    let mut j = lines.len();
+    // first line of all-stars should be omitted
+    if !lines.is_empty() && lines[0].chars().all(|c| c == '*') {
+        i += 1;
+    }
+
+    while i < j && lines[i].trim().is_empty() {
+        i += 1;
+    }
+    // like the first, a last line of all stars should be omitted
+    if j > i && lines[j - 1].chars().skip(1).all(|c| c == '*') {
+        j -= 1;
+    }
+
+    while j > i && lines[j - 1].trim().is_empty() {
+        j -= 1;
+    }
+
+    lines[i..j].to_vec()
+}
+
+/// remove a "[ \t]*\*" block from each line, if possible
+pub fn horizontal_trim(lines: Vec<String>) -> Vec<String> {
+    let mut i = usize::MAX;
+    let mut can_trim = true;
+    let mut first = true;
+
+    for line in &lines {
+        for (j, c) in line.chars().enumerate() {
+            if j > i || !"* \t".contains(c) {
+                can_trim = false;
+                break;
+            }
+            if c == '*' {
+                if first {
+                    i = j;
+                    first = false;
+                } else if i != j {
+                    can_trim = false;
+                }
+                break;
+            }
+        }
+        if i >= line.len() {
+            can_trim = false;
+        }
+        if !can_trim {
+            break;
+        }
+    }
+
+    if can_trim {
+        lines.iter().map(|line| (&line[i + 1..line.len()]).to_string()).collect()
+    } else {
+        lines
+    }
+}