Omit unnecessary UTF-8 decoding

sinkuu · sinkuu · commit 83c8d23cc27f · 2018-03-22T08:34:53.000+09:00
diff --git a/src/utils.rs b/src/utils.rs
@@ -251,7 +251,8 @@ pub fn stmt_expr(stmt: &ast::Stmt) -> Option<&ast::Expr> {
 
 #[inline]
 pub fn count_newlines(input: &str) -> usize {
-    input.chars().filter(|&c| c == '\n').count()
+    // Using `as_bytes` to omit UTF-8 decoding
+    input.as_bytes().iter().filter(|&&c| c == b'\n').count()
 }
 
 macro_rules! msg {

Original file line number	Diff line number	Diff line change
`@@ -251,7 +251,8 @@ pub fn stmt_expr(stmt: &ast::Stmt) -> Option<&ast::Expr> {`
`251`	`251`
`252`	`252`	`#[inline]`
`253`	`253`	`pub fn count_newlines(input: &str) -> usize {`
`254`		`- input.chars().filter(\|&c\| c == '\n').count()`
	`254`	+ // Using `as_bytes` to omit UTF-8 decoding
	`255`	`+ input.as_bytes().iter().filter(\|&&c\| c == b'\n').count()`
`255`	`256`	`}`
`256`	`257`
`257`	`258`	`macro_rules! msg {`