utils: Add CodeMapSpanUtils trait for span_* methods

This commit adds a CodeMapSpanUtils extension trait on CodeMap, and
moves some functions to methods there:
  - span_after
  - span_after_last
  - span_before

This better reflects them being lookup methods on the codemap.

1 files changed, 35 insertions, 27 deletions

diff --git a/src/utils.rs b/src/utils.rs
index 3b03ede2be3..5c2bca73432 100644
--- a/src/utils.rs
+++ b/src/utils.rs
@@ -20,42 +20,50 @@ use rewrite::{Rewrite, RewriteContext};
 
 use SKIP_ANNOTATION;
 
-// Computes the length of a string's last line, minus offset.
-#[inline]
-pub fn extra_offset(text: &str, offset: Indent) -> usize {
-    match text.rfind('\n') {
-        // 1 for newline character
-        Some(idx) => text.len() - idx - 1 - offset.width(),
-        None => text.len(),
-    }
+pub trait CodeMapSpanUtils {
+    fn span_after(&self, original: Span, needle: &str) -> BytePos;
+    fn span_after_last(&self, original: Span, needle: &str) -> BytePos;
+    fn span_before(&self, original: Span, needle: &str) -> BytePos;
 }
 
-#[inline]
-pub fn span_after(original: Span, needle: &str, codemap: &CodeMap) -> BytePos {
-    let snippet = codemap.span_to_snippet(original).unwrap();
-    let offset = snippet.find_uncommented(needle).unwrap() + needle.len();
+impl CodeMapSpanUtils for CodeMap {
+    #[inline]
+    fn span_after(&self, original: Span, needle: &str) -> BytePos {
+        let snippet = self.span_to_snippet(original).unwrap();
+        let offset = snippet.find_uncommented(needle).unwrap() + needle.len();
 
-    original.lo + BytePos(offset as u32)
-}
+        original.lo + BytePos(offset as u32)
+    }
 
-#[inline]
-pub fn span_before(original: Span, needle: &str, codemap: &CodeMap) -> BytePos {
-    let snippet = codemap.span_to_snippet(original).unwrap();
-    let offset = snippet.find_uncommented(needle).unwrap();
+    #[inline]
+    fn span_after_last(&self, original: Span, needle: &str) -> BytePos {
+        let snippet = self.span_to_snippet(original).unwrap();
+        let mut offset = 0;
 
-    original.lo + BytePos(offset as u32)
-}
+        while let Some(additional_offset) = snippet[offset..].find_uncommented(needle) {
+            offset += additional_offset + needle.len();
+        }
 
-#[inline]
-pub fn span_after_last(original: Span, needle: &str, codemap: &CodeMap) -> BytePos {
-    let snippet = codemap.span_to_snippet(original).unwrap();
-    let mut offset = 0;
+        original.lo + BytePos(offset as u32)
+    }
+
+    #[inline]
+    fn span_before(&self, original: Span, needle: &str) -> BytePos {
+        let snippet = self.span_to_snippet(original).unwrap();
+        let offset = snippet.find_uncommented(needle).unwrap();
 
-    while let Some(additional_offset) = snippet[offset..].find_uncommented(needle) {
-        offset += additional_offset + needle.len();
+        original.lo + BytePos(offset as u32)
     }
+}
 
-    original.lo + BytePos(offset as u32)
+// Computes the length of a string's last line, minus offset.
+#[inline]
+pub fn extra_offset(text: &str, offset: Indent) -> usize {
+    match text.rfind('\n') {
+        // 1 for newline character
+        Some(idx) => text.len() - idx - 1 - offset.width(),
+        None => text.len(),
+    }
 }
 
 #[inline]