A bit of refactoring. Moved bodies of the most of closures related to parsing numbers into regular functions.

Author: KOLANICH

src/parser.rs

@@ -126,6 +126,26 @@ impl<'a> Debug for LineReader<'a> {
     }
 }
 
+fn is_digit(c: &&u8) -> bool {
+    **c >= b'0' && **c <= b'9'
+}
+
+fn is_octal_digit(c: &&u8) -> bool {
+    **c >= b'0' && **c <= b'7'
+}
+
+fn decimal_reducer_usize(r: usize, c: &u8) -> usize {
+    r * 10 + usize::from(*c - b'0')
+}
+
+fn decimal_reducer_u32(r: u32, c: &u8) -> u32 {
+    r * 10 + u32::from(*c - b'0')
+}
+
+fn octal_reducer_u32(r: u32, c: &u8) -> u32 {
+    r * 8 + u32::from(*c - b'0')
+}
+
 impl<'a> LineReader<'a> {
     fn is_empty(&self) -> bool {
         self.buf.is_empty()
@@ -188,15 +208,15 @@ impl<'a> LineReader<'a> {
         // NUMS_PAT = re.compile(r'^@@ -([0-9]+),?([0-9]+)? \+([0-9]+),?([0-9]+)? @@')
         let iter = &mut buf.iter();
         let old_start = iter
-            .take_while(|&&c| c >= b'0' && c <= b'9')
-            .fold(0, |r, &c| r * 10 + u32::from(c - b'0'));
+            .take_while(is_digit)
+            .fold(0, decimal_reducer_u32);
 
         let c = *iter
             .next()
             .ok_or_else(|| ParsepatchError::InvalidHunkHeader(self.get_line()))?;
-        let old_lines = if c >= b'0' && c <= b'9' {
-            iter.take_while(|&&c| c >= b'0' && c <= b'9')
-                .fold(u32::from(c - b'0'), |r, &c| r * 10 + u32::from(c - b'0'))
+        let old_lines = if is_digit(&&c) {
+            iter.take_while(is_digit)
+                .fold(u32::from(c - b'0'), decimal_reducer_u32)
         } else {
             1
         };
@@ -206,15 +226,15 @@ impl<'a> LineReader<'a> {
         }
 
         let new_start = iter
-            .take_while(|&&c| c >= b'0' && c <= b'9')
-            .fold(0, |r, &c| r * 10 + u32::from(c - b'0'));
+            .take_while(is_digit)
+            .fold(0, decimal_reducer_u32);
 
         let c = *iter
             .next()
             .ok_or_else(|| ParsepatchError::InvalidHunkHeader(self.get_line()))?;
-        let new_lines = if c >= b'0' && c <= b'9' {
-            iter.take_while(|&&c| c >= b'0' && c <= b'9')
-                .fold(u32::from(c - b'0'), |r, &c| r * 10 + u32::from(c - b'0'))
+        let new_lines = if is_digit(&&c) {
+            iter.take_while(is_digit)
+                .fold(u32::from(c - b'0'), decimal_reducer_u32)
         } else {
             1
         };
@@ -290,8 +310,8 @@ impl<'a> LineReader<'a> {
         // the following number is an octal number with 6 digits (so max is 8^6 - 1)
         let buf = unsafe { self.buf.get_unchecked(start.len()..) };
         buf.iter()
-            .take_while(|&&c| c >= b'0' && c <= b'7')
-            .fold(0, |r, &c| r * 8 + u32::from(c - b'0'))
+            .take_while(is_octal_digit)
+            .fold(0, octal_reducer_u32)
     }
 }
 
@@ -659,8 +679,8 @@ impl<'a> PatchReader<'a> {
 
     fn parse_usize(buf: &[u8]) -> usize {
         buf.iter()
-            .take_while(|&&c| c >= b'0' && c <= b'9')
-            .fold(0, |r, &c| r * 10 + usize::from(c - b'0'))
+            .take_while(is_digit)
+            .fold(0, decimal_reducer_usize)
     }
 
     fn skip_binary(&mut self) -> Vec<BinaryHunk> {