Make column and line numbers match Gecko's CSS parser.

src/tests.rs

@@ -451,26 +451,26 @@ fn serialize_rgba_two_digit_float_if_roundtrips() {
 fn line_numbers() {
     let mut input = ParserInput::new("foo bar\nbaz\r\n\n\"a\\\r\nb\"");
     let mut input = Parser::new(&mut input);
-    assert_eq!(input.current_source_location(), SourceLocation { line: 1, column: 1 });
+    assert_eq!(input.current_source_location(), SourceLocation { line: 0, column: 0 });
     assert_eq!(input.next_including_whitespace(), Ok(Token::Ident("foo".into())));
-    assert_eq!(input.current_source_location(), SourceLocation { line: 1, column: 4 });
+    assert_eq!(input.current_source_location(), SourceLocation { line: 0, column: 3 });
     assert_eq!(input.next_including_whitespace(), Ok(Token::WhiteSpace(" ")));
-    assert_eq!(input.current_source_location(), SourceLocation { line: 1, column: 5 });
+    assert_eq!(input.current_source_location(), SourceLocation { line: 0, column: 4 });
     assert_eq!(input.next_including_whitespace(), Ok(Token::Ident("bar".into())));
-    assert_eq!(input.current_source_location(), SourceLocation { line: 1, column: 8 });
+    assert_eq!(input.current_source_location(), SourceLocation { line: 0, column: 7 });
     assert_eq!(input.next_including_whitespace(), Ok(Token::WhiteSpace("\n")));
-    assert_eq!(input.current_source_location(), SourceLocation { line: 2, column: 1 });
+    assert_eq!(input.current_source_location(), SourceLocation { line: 1, column: 0 });
     assert_eq!(input.next_including_whitespace(), Ok(Token::Ident("baz".into())));
-    assert_eq!(input.current_source_location(), SourceLocation { line: 2, column: 4 });
+    assert_eq!(input.current_source_location(), SourceLocation { line: 1, column: 3 });
     let position = input.position();
 
     assert_eq!(input.next_including_whitespace(), Ok(Token::WhiteSpace("\r\n\n")));
-    assert_eq!(input.current_source_location(), SourceLocation { line: 4, column: 1 });
+    assert_eq!(input.current_source_location(), SourceLocation { line: 3, column: 0 });
 
-    assert_eq!(input.source_location(position), SourceLocation { line: 2, column: 4 });
+    assert_eq!(input.source_location(position), SourceLocation { line: 1, column: 3 });
 
     assert_eq!(input.next_including_whitespace(), Ok(Token::QuotedString("ab".into())));
-    assert_eq!(input.current_source_location(), SourceLocation { line: 5, column: 3 });
+    assert_eq!(input.current_source_location(), SourceLocation { line: 4, column: 2 });
     assert!(input.next_including_whitespace().is_err());
 }
 

src/tokenizer.rs

@@ -226,7 +226,7 @@ impl<'a> Tokenizer<'a> {
             input: input,
             position: 0,
             last_known_source_location: Cell::new((SourcePosition(0),
-                                                   SourceLocation { line: 1, column: 1 })),
+                                                   SourceLocation { line: 0, column: 0 })),
             var_functions: SeenStatus::DontCare,
             viewport_percentages: SeenStatus::DontCare,
         }
@@ -312,7 +312,7 @@ impl<'a> Tokenizer<'a> {
             // So if the requested position is before the last known one,
             // start over from the beginning.
             position = 0;
-            location = SourceLocation { line: 1, column: 1 };
+            location = SourceLocation { line: 0, column: 0 };
         }
         let mut source = &self.input[position..target];
         while let Some(newline_position) = source.find(|c| matches!(c, '\n' | '\r' | '\x0C')) {
@@ -321,7 +321,7 @@ impl<'a> Tokenizer<'a> {
             source = &source[offset..];
             position += offset;
             location.line += 1;
-            location.column = 1;
+            location.column = 0;
         }
         debug_assert!(position <= target);
         location.column += (target - position) as u32;
@@ -397,10 +397,10 @@ pub struct SourcePosition(usize);
 /// The line and column number for a given position within the input.
 #[derive(PartialEq, Eq, Debug, Clone, Copy)]
 pub struct SourceLocation {
-    /// The line number, starting at 1 for the first line.
+    /// The line number, starting at 0 for the first line.
     pub line: u32,
 
-    /// The column number within a line, starting at 1 for first the character of the line.
+    /// The column number within a line, starting at 0 for first the character of the line.
     pub column: u32,
 }