diff --git a/compiler/rustc_lexer/src/cursor.rs b/compiler/rustc_lexer/src/cursor.rs
deleted file mode 100644
index 165262b82c75..000000000000
--- a/compiler/rustc_lexer/src/cursor.rs
+++ /dev/null
@@ -1,125 +0,0 @@
-use std::str::Chars;
-
-pub enum FrontmatterAllowed {
-    Yes,
-    No,
-}
-
-/// Peekable iterator over a char sequence.
-///
-/// Next characters can be peeked via `first` method,
-/// and position can be shifted forward via `bump` method.
-pub struct Cursor<'a> {
-    len_remaining: usize,
-    /// Iterator over chars. Slightly faster than a &str.
-    chars: Chars<'a>,
-    pub(crate) frontmatter_allowed: FrontmatterAllowed,
-    #[cfg(debug_assertions)]
-    prev: char,
-}
-
-pub(crate) const EOF_CHAR: char = '\0';
-
-impl<'a> Cursor<'a> {
-    pub fn new(input: &'a str, frontmatter_allowed: FrontmatterAllowed) -> Cursor<'a> {
-        Cursor {
-            len_remaining: input.len(),
-            chars: input.chars(),
-            frontmatter_allowed,
-            #[cfg(debug_assertions)]
-            prev: EOF_CHAR,
-        }
-    }
-
-    pub fn as_str(&self) -> &'a str {
-        self.chars.as_str()
-    }
-
-    /// Returns the last eaten symbol (or `'\0'` in release builds).
-    /// (For debug assertions only.)
-    pub(crate) fn prev(&self) -> char {
-        #[cfg(debug_assertions)]
-        {
-            self.prev
-        }
-
-        #[cfg(not(debug_assertions))]
-        {
-            EOF_CHAR
-        }
-    }
-
-    /// Peeks the next symbol from the input stream without consuming it.
-    /// If requested position doesn't exist, `EOF_CHAR` is returned.
-    /// However, getting `EOF_CHAR` doesn't always mean actual end of file,
-    /// it should be checked with `is_eof` method.
-    pub fn first(&self) -> char {
-        // `.next()` optimizes better than `.nth(0)`
-        self.chars.clone().next().unwrap_or(EOF_CHAR)
-    }
-
-    /// Peeks the second symbol from the input stream without consuming it.
-    pub(crate) fn second(&self) -> char {
-        // `.next()` optimizes better than `.nth(1)`
-        let mut iter = self.chars.clone();
-        iter.next();
-        iter.next().unwrap_or(EOF_CHAR)
-    }
-
-    /// Peeks the third symbol from the input stream without consuming it.
-    pub fn third(&self) -> char {
-        // `.next()` optimizes better than `.nth(2)`
-        let mut iter = self.chars.clone();
-        iter.next();
-        iter.next();
-        iter.next().unwrap_or(EOF_CHAR)
-    }
-
-    /// Checks if there is nothing more to consume.
-    pub(crate) fn is_eof(&self) -> bool {
-        self.chars.as_str().is_empty()
-    }
-
-    /// Returns amount of already consumed symbols.
-    pub(crate) fn pos_within_token(&self) -> u32 {
-        (self.len_remaining - self.chars.as_str().len()) as u32
-    }
-
-    /// Resets the number of bytes consumed to 0.
-    pub(crate) fn reset_pos_within_token(&mut self) {
-        self.len_remaining = self.chars.as_str().len();
-    }
-
-    /// Moves to the next character.
-    pub(crate) fn bump(&mut self) -> Option<char> {
-        let c = self.chars.next()?;
-
-        #[cfg(debug_assertions)]
-        {
-            self.prev = c;
-        }
-
-        Some(c)
-    }
-
-    /// Moves to a substring by a number of bytes.
-    pub(crate) fn bump_bytes(&mut self, n: usize) {
-        self.chars = self.as_str()[n..].chars();
-    }
-
-    /// Eats symbols while predicate returns true or until the end of file is reached.
-    pub(crate) fn eat_while(&mut self, mut predicate: impl FnMut(char) -> bool) {
-        // It was tried making optimized version of this for eg. line comments, but
-        // LLVM can inline all of this and compile it down to fast iteration over bytes.
-        while predicate(self.first()) && !self.is_eof() {
-            self.bump();
-        }
-    }
-
-    pub(crate) fn eat_until(&mut self, byte: u8) {
-        self.chars = match memchr::memchr(byte, self.as_str().as_bytes()) {
-            Some(index) => self.as_str()[index..].chars(),
-            None => "".chars(),
-        }
-    }
-}
diff --git a/compiler/rustc_lexer/src/lib.rs b/compiler/rustc_lexer/src/lib.rs
index 27ffcbc943bd..9d3da6ef4930 100644
--- a/compiler/rustc_lexer/src/lib.rs
+++ b/compiler/rustc_lexer/src/lib.rs
@@ -25,15 +25,13 @@
 #![deny(unstable_features)]
 // tidy-alphabetical-end
 
-mod cursor;
-
 #[cfg(test)]
 mod tests;
 
+use std::str::Chars;
+
 use LiteralKind::*;
 use TokenKind::*;
-use cursor::EOF_CHAR;
-pub use cursor::{Cursor, FrontmatterAllowed};
 pub use unicode_ident::UNICODE_VERSION;
 use unicode_properties::UnicodeEmoji;
 
@@ -407,7 +405,129 @@ pub fn is_ident(string: &str) -> bool {
     }
 }
 
-impl Cursor<'_> {
+pub enum FrontmatterAllowed {
+    Yes,
+    No,
+}
+
+/// Peekable iterator over a char sequence.
+///
+/// Next characters can be peeked via `first` method,
+/// and position can be shifted forward via `bump` method.
+pub struct Cursor<'a> {
+    len_remaining: usize,
+    /// Iterator over chars. Slightly faster than a &str.
+    chars: Chars<'a>,
+    pub(crate) frontmatter_allowed: FrontmatterAllowed,
+    #[cfg(debug_assertions)]
+    prev: char,
+}
+
+const EOF_CHAR: char = '\0';
+
+impl<'a> Cursor<'a> {
+    pub fn new(input: &'a str, frontmatter_allowed: FrontmatterAllowed) -> Cursor<'a> {
+        Cursor {
+            len_remaining: input.len(),
+            chars: input.chars(),
+            frontmatter_allowed,
+            #[cfg(debug_assertions)]
+            prev: EOF_CHAR,
+        }
+    }
+
+    pub fn as_str(&self) -> &'a str {
+        self.chars.as_str()
+    }
+
+    /// Returns the last eaten symbol (or `'\0'` in release builds).
+    /// (For debug assertions only.)
+    pub(crate) fn prev(&self) -> char {
+        #[cfg(debug_assertions)]
+        {
+            self.prev
+        }
+
+        #[cfg(not(debug_assertions))]
+        {
+            EOF_CHAR
+        }
+    }
+
+    /// Peeks the next symbol from the input stream without consuming it.
+    /// If requested position doesn't exist, `EOF_CHAR` is returned.
+    /// However, getting `EOF_CHAR` doesn't always mean actual end of file,
+    /// it should be checked with `is_eof` method.
+    pub fn first(&self) -> char {
+        // `.next()` optimizes better than `.nth(0)`
+        self.chars.clone().next().unwrap_or(EOF_CHAR)
+    }
+
+    /// Peeks the second symbol from the input stream without consuming it.
+    pub(crate) fn second(&self) -> char {
+        // `.next()` optimizes better than `.nth(1)`
+        let mut iter = self.chars.clone();
+        iter.next();
+        iter.next().unwrap_or(EOF_CHAR)
+    }
+
+    /// Peeks the third symbol from the input stream without consuming it.
+    pub fn third(&self) -> char {
+        // `.next()` optimizes better than `.nth(2)`
+        let mut iter = self.chars.clone();
+        iter.next();
+        iter.next();
+        iter.next().unwrap_or(EOF_CHAR)
+    }
+
+    /// Checks if there is nothing more to consume.
+    pub(crate) fn is_eof(&self) -> bool {
+        self.chars.as_str().is_empty()
+    }
+
+    /// Returns amount of already consumed symbols.
+    pub(crate) fn pos_within_token(&self) -> u32 {
+        (self.len_remaining - self.chars.as_str().len()) as u32
+    }
+
+    /// Resets the number of bytes consumed to 0.
+    pub(crate) fn reset_pos_within_token(&mut self) {
+        self.len_remaining = self.chars.as_str().len();
+    }
+
+    /// Moves to the next character.
+    pub(crate) fn bump(&mut self) -> Option<char> {
+        let c = self.chars.next()?;
+
+        #[cfg(debug_assertions)]
+        {
+            self.prev = c;
+        }
+
+        Some(c)
+    }
+
+    /// Moves to a substring by a number of bytes.
+    pub(crate) fn bump_bytes(&mut self, n: usize) {
+        self.chars = self.as_str()[n..].chars();
+    }
+
+    /// Eats symbols while predicate returns true or until the end of file is reached.
+    pub(crate) fn eat_while(&mut self, mut predicate: impl FnMut(char) -> bool) {
+        // It was tried making optimized version of this for eg. line comments, but
+        // LLVM can inline all of this and compile it down to fast iteration over bytes.
+        while predicate(self.first()) && !self.is_eof() {
+            self.bump();
+        }
+    }
+
+    pub(crate) fn eat_until(&mut self, byte: u8) {
+        self.chars = match memchr::memchr(byte, self.as_str().as_bytes()) {
+            Some(index) => self.as_str()[index..].chars(),
+            None => "".chars(),
+        }
+    }
+
     /// Parses a token from the input string.
     pub fn advance_token(&mut self) -> Token {
         let Some(first_char) = self.bump() else {