From 0ff08f3a9f8e1a9ddaacca917300dd62b82852ff Mon Sep 17 00:00:00 2001
From: Alexandre Bury <alexandre.bury@gmail.com>
Date: Fri, 16 Feb 2018 16:56:25 -0800
Subject: [PATCH] Add Row::overall_indices

---
 src/utils/lines/spans/row.rs     | 15 ++++++++++++++-
 src/utils/lines/spans/segment.rs | 22 ++++++++++++++++++----
 2 files changed, 32 insertions(+), 5 deletions(-)

diff --git a/src/utils/lines/spans/row.rs b/src/utils/lines/spans/row.rs
index 33d202e..c75c205 100644
--- a/src/utils/lines/spans/row.rs
+++ b/src/utils/lines/spans/row.rs
@@ -1,5 +1,5 @@
 use super::Segment;
-use utils::span::{Span, AsSpannedStr};
+use utils::span::{AsSpannedStr, IndexedCow, Span};
 
 /// A list of segments representing a row of text
 #[derive(Debug, Clone, PartialEq, Eq)]
@@ -23,4 +23,17 @@ impl Row {
             .map(|seg| seg.resolve(source.clone()))
             .collect()
     }
+
+    /// Returns indices in the source string, if possible.
+    ///
+    /// Returns overall `(start, end)`, or `None` if the segments are owned.
+    pub fn overall_indices<S>(&self, spans: &[S]) -> Option<(usize, usize)>
+    where
+        S: AsRef<IndexedCow>,
+    {
+        let (start, _) = self.segments.get(0)?.source_indices(spans)?;
+        let (_, end) = self.segments.last()?.source_indices(spans)?;
+
+        Some((start, end))
+    }
 }
diff --git a/src/utils/lines/spans/segment.rs b/src/utils/lines/spans/segment.rs
index 104cbe4..0a9d9cf 100644
--- a/src/utils/lines/spans/segment.rs
+++ b/src/utils/lines/spans/segment.rs
@@ -1,4 +1,4 @@
-use utils::span::{SpannedStr, Span, SpannedText};
+use utils::span::{Span, SpannedStr, SpannedText, IndexedCow};
 
 /// Refers to a part of a span
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
@@ -17,9 +17,7 @@ pub struct Segment {
 
 impl Segment {
     /// Resolve this segment to a string slice and an attribute.
-    pub fn resolve<'a, T>(
-        &self, source: SpannedStr<'a, T>
-    ) -> Span<'a, T> {
+    pub fn resolve<'a, T>(&self, source: SpannedStr<'a, T>) -> Span<'a, T> {
         let span = &source.spans_raw()[self.span_id];
 
         let content = span.content.resolve(source.source());
@@ -43,4 +41,20 @@ impl Segment {
 
         content
     }
+
+    /// Returns indices in the source string, if possible.
+    ///
+    /// Returns `(start, end)`, or `None` if the target span is an owned string.
+    pub fn source_indices<S>(&self, spans: &[S]) -> Option<(usize, usize)>
+    where
+        S: AsRef<IndexedCow>,
+    {
+        let span = spans[self.span_id].as_ref();
+
+        if let &IndexedCow::Borrowed { start, .. } = span {
+            Some((self.start + start, self.end + start))
+        } else {
+            None
+        }
+    }
 }