Introduce InnerSpan abstraction

This should be used when trying to get at subsets of a larger span,
especially when the larger span is not available in the code attempting
to work with those subsets (especially common in the fmt_macros crate).

This is usually a good replacement for (BytePos, BytePos) and (usize,
usize) tuples.

This commit also removes from_inner_byte_pos, since it took usize
arguments, which is error prone.

2 files changed, 20 insertions, 20 deletions

diff --git a/src/libsyntax_ext/format.rs b/src/libsyntax_ext/format.rs
index 1fdc2e6274a..85b524786b2 100644
--- a/src/libsyntax_ext/format.rs
+++ b/src/libsyntax_ext/format.rs
@@ -900,15 +900,15 @@ pub fn expand_preparsed_format_args(ecx: &mut ExtCtxt<'_>,
 
     if !parser.errors.is_empty() {
         let err = parser.errors.remove(0);
-        let sp = fmt.span.from_inner_byte_pos(err.start.unwrap(), err.end.unwrap());
+        let sp = fmt.span.from_inner(err.span);
         let mut e = ecx.struct_span_err(sp, &format!("invalid format string: {}",
                                                      err.description));
         e.span_label(sp, err.label + " in format string");
         if let Some(note) = err.note {
             e.note(&note);
         }
-        if let Some((label, start, end)) = err.secondary_label {
-            let sp = fmt.span.from_inner_byte_pos(start.unwrap(), end.unwrap());
+        if let Some((label, span)) = err.secondary_label {
+            let sp = fmt.span.from_inner(span);
             e.span_label(sp, label);
         }
         e.emit();
@@ -916,9 +916,7 @@ pub fn expand_preparsed_format_args(ecx: &mut ExtCtxt<'_>,
     }
 
     let arg_spans = parser.arg_places.iter()
-        .map(|&(parse::SpanIndex(start), parse::SpanIndex(end))| {
-            fmt.span.from_inner_byte_pos(start, end)
-        })
+        .map(|span| fmt.span.from_inner(*span))
         .collect();
 
     let mut cx = Context {
@@ -1065,8 +1063,8 @@ pub fn expand_preparsed_format_args(ecx: &mut ExtCtxt<'_>,
                             show_doc_note = true;
                         }
 
-                        if let Some((start, end)) = pos {
-                            let sp = fmt_sp.from_inner_byte_pos(start, end);
+                        if let Some(inner_sp) = pos {
+                            let sp = fmt_sp.from_inner(inner_sp);
                             suggestions.push((sp, trn));
                         } else {
                             diag.help(&format!("`{}` should be written as `{}`", sub, trn));
diff --git a/src/libsyntax_ext/format_foreign.rs b/src/libsyntax_ext/format_foreign.rs
index b279dbced84..7ad5997bf2c 100644
--- a/src/libsyntax_ext/format_foreign.rs
+++ b/src/libsyntax_ext/format_foreign.rs
@@ -1,5 +1,6 @@
 pub mod printf {
     use super::strcursor::StrCursor as Cur;
+    use syntax_pos::InnerSpan;
 
     /// Represents a single `printf`-style substitution.
     #[derive(Clone, PartialEq, Debug)]
@@ -18,7 +19,7 @@ pub mod printf {
             }
         }
 
-        pub fn position(&self) -> Option<(usize, usize)> {
+        pub fn position(&self) -> Option<InnerSpan> {
             match *self {
                 Substitution::Format(ref fmt) => Some(fmt.position),
                 _ => None,
@@ -28,7 +29,7 @@ pub mod printf {
         pub fn set_position(&mut self, start: usize, end: usize) {
             match self {
                 Substitution::Format(ref mut fmt) => {
-                    fmt.position = (start, end);
+                    fmt.position = InnerSpan::new(start, end);
                 }
                 _ => {}
             }
@@ -65,7 +66,7 @@ pub mod printf {
         /// Type of parameter being converted.
         pub type_: &'a str,
         /// Byte offset for the start and end of this formatting directive.
-        pub position: (usize, usize),
+        pub position: InnerSpan,
     }
 
     impl Format<'_> {
@@ -282,9 +283,9 @@ pub mod printf {
             let (mut sub, tail) = parse_next_substitution(self.s)?;
             self.s = tail;
             match sub {
-                Substitution::Format(_) => if let Some((start, end)) = sub.position() {
-                    sub.set_position(start + self.pos, end + self.pos);
-                    self.pos += end;
+                Substitution::Format(_) => if let Some(inner_span) = sub.position() {
+                    sub.set_position(inner_span.start + self.pos, inner_span.end + self.pos);
+                    self.pos += inner_span.end;
                 }
                 Substitution::Escape => self.pos += 2,
             }
@@ -373,7 +374,7 @@ pub mod printf {
                     precision: None,
                     length: None,
                     type_: at.slice_between(next).unwrap(),
-                    position: (start.at, next.at),
+                    position: InnerSpan::new(start.at, next.at),
                 }),
                 next.slice_after()
             ));
@@ -560,7 +561,7 @@ pub mod printf {
         drop(next);
 
         end = at;
-        let position = (start.at, end.at);
+        let position = InnerSpan::new(start.at, end.at);
 
         let f = Format {
             span: start.slice_between(end).unwrap(),
@@ -650,7 +651,7 @@ pub mod printf {
                                 precision: $prec,
                                 length: $len,
                                 type_: $type_,
-                                position: $pos,
+                                position: syntax_pos::InnerSpan::new($pos.0, $pos.1),
                             }),
                             "!"
                         ))
@@ -761,6 +762,7 @@ pub mod printf {
 
 pub mod shell {
     use super::strcursor::StrCursor as Cur;
+    use syntax_pos::InnerSpan;
 
     #[derive(Clone, PartialEq, Debug)]
     pub enum Substitution<'a> {
@@ -778,11 +780,11 @@ pub mod shell {
             }
         }
 
-        pub fn position(&self) -> Option<(usize, usize)> {
+        pub fn position(&self) -> Option<InnerSpan> {
             match self {
                 Substitution::Ordinal(_, pos) |
                 Substitution::Name(_, pos) |
-                Substitution::Escape(pos) => Some(*pos),
+                Substitution::Escape(pos) => Some(InnerSpan::new(pos.0, pos.1)),
             }
         }
 
@@ -823,7 +825,7 @@ pub mod shell {
             match parse_next_substitution(self.s) {
                 Some((mut sub, tail)) => {
                     self.s = tail;
-                    if let Some((start, end)) = sub.position() {
+                    if let Some(InnerSpan { start, end }) = sub.position() {
                         sub.set_position(start + self.pos, end + self.pos);
                         self.pos += end;
                     }