1 files changed, 89 insertions, 0 deletions
diff --git a/third_party/rust/fluent-syntax/src/parser/comment.rs b/third_party/rust/fluent-syntax/src/parser/comment.rs
new file mode 100644
index 0000000000..a63483c1d3
--- /dev/null
+++ b/third_party/rust/fluent-syntax/src/parser/comment.rs
@@ -0,0 +1,89 @@
+use super::{core::Parser, core::Result, Slice};
+use crate::ast;
+
+#[derive(Debug, PartialEq, Clone, Copy)]
+pub(super) enum Level {
+    None = 0,
+    Regular = 1,
+    Group = 2,
+    Resource = 3,
+}
+
+impl<'s, S> Parser<S>
+where
+    S: Slice<'s>,
+{
+    pub(super) fn get_comment(&mut self) -> Result<(ast::Comment<S>, Level)> {
+        let mut level = Level::None;
+        let mut content = vec![];
+
+        while self.ptr < self.length {
+            let line_level = self.get_comment_level();
+            if line_level == Level::None {
+                self.ptr -= 1;
+                break;
+            } else if level != Level::None && line_level != level {
+                self.ptr -= line_level as usize;
+                break;
+            }
+
+            level = line_level;
+
+            if self.ptr == self.length {
+                break;
+            } else if self.is_current_byte(b'\n') {
+                content.push(self.get_comment_line());
+            } else {
+                if let Err(e) = self.expect_byte(b' ') {
+                    if content.is_empty() {
+                        return Err(e);
+                    } else {
+                        self.ptr -= line_level as usize;
+                        break;
+                    }
+                }
+                content.push(self.get_comment_line());
+            }
+            self.skip_eol();
+        }
+
+        Ok((ast::Comment { content }, level))
+    }
+
+    pub(super) fn skip_comment(&mut self) {
+        loop {
+            while self.ptr < self.length && !self.is_current_byte(b'\n') {
+                self.ptr += 1;
+            }
+            self.ptr += 1;
+            if self.is_current_byte(b'#') {
+                self.ptr += 1;
+            } else {
+                break;
+            }
+        }
+    }
+
+    fn get_comment_level(&mut self) -> Level {
+        if self.take_byte_if(b'#') {
+            if self.take_byte_if(b'#') {
+                if self.take_byte_if(b'#') {
+                    return Level::Resource;
+                }
+                return Level::Group;
+            }
+            return Level::Regular;
+        }
+        Level::None
+    }
+
+    fn get_comment_line(&mut self) -> S {
+        let start_pos = self.ptr;
+
+        while !self.is_eol() {
+            self.ptr += 1;
+        }
+
+        self.source.slice(start_pos..self.ptr)
+    }
+}