The magic part moved into nom_locate.

Cargo.toml

@@ -29,7 +29,7 @@ spectest = ["yaml-rust", "deunicode", "hrx-get", "regex"]
 [dependencies]
 lazy_static = "1.0"
 nom = "5.0.0"
-nom_locate = "2.0.0"
+nom_locate = { git = "https://github.com/fflorent/nom_locate" }
 num-bigint = { version = "0.3.0", default-features = false, features = ["std"] }
 num-integer = "0.1.42"
 num-rational = { version = "0.3.0", default-features = false }

src/error.rs

@@ -112,7 +112,7 @@ impl<'a> From<ParseError<'a>> for Error {
     fn from(err: ParseError) -> Self {
         Error::ParseError {
             msg: format!("Parse error: {:?}", err.err),
-            pos: SourcePos::magic_pos(err.span),
+            pos: err.span.into(),
         }
     }
 }

src/lib.rs

@@ -36,7 +36,7 @@
 //! That said, this implementation has reached a version where I find it
 //! usable for my personal projects, and the number of working tests are
 //! improving.
-//#![forbid(unsafe_code)]
+#![forbid(unsafe_code)]
 use std::path::Path;
 
 pub mod css;

src/parser/mod.rs

@@ -259,11 +259,7 @@ fn import2(input: Span) -> IResult<Span, Item> {
             ),
         ),
         |(position, import, args)| {
-            Item::Import(
-                import,
-                args.unwrap_or(Value::Null),
-                SourcePos::magic_pos(position),
-            )
+            Item::Import(import, args.unwrap_or(Value::Null), position.into())
         },
     )(input)
 }

src/parser/pos.rs

@@ -10,32 +10,12 @@ pub struct SourcePos {
     pub file: SourceName,
 }
 
-impl SourcePos {
-    pub fn magic_pos(span: Span) -> Self {
-        use std::slice;
-
-        let self_bytes = span.fragment();
-        let self_ptr = self_bytes.as_ptr();
-        let offset = span.get_column() - 1;
-        let the_line = unsafe {
-            assert!(
-                offset <= isize::max_value() as usize,
-                "offset is too big"
-            );
-            let orig_input_ptr = self_ptr.offset(-(offset as isize));
-            slice::from_raw_parts(
-                orig_input_ptr,
-                offset + span.fragment().len(),
-            )
-        };
-        let the_line = the_line
-            .split(|c| *c == b'\n')
-            .next()
-            .and_then(|s| from_utf8(s).ok())
-            .unwrap_or("<<failed to display line>>");
-
+impl From<Span<'_>> for SourcePos {
+    fn from(span: Span) -> Self {
         SourcePos {
-            line: the_line.to_string(),
+            line: from_utf8(span.get_line_beginning())
+                .unwrap_or("<<failed to display line>>")
+                .to_string(),
             line_no: span.location_line(),
             line_pos: span.get_utf8_column(),
             file: span.extra.clone(),