1 files changed, 30 insertions, 1 deletions
diff --git a/src/strings/strings.go b/src/strings/strings.go
index a98f5d8ff1..e14fffb2b8 100644
--- a/src/strings/strings.go
+++ b/src/strings/strings.go
@@ -818,7 +818,36 @@ func TrimRight(s string, cutset string) string {
 // TrimSpace returns a slice of the string s, with all leading
 // and trailing white space removed, as defined by Unicode.
 func TrimSpace(s string) string {
-	return TrimFunc(s, unicode.IsSpace)
+	// Fast path for ASCII: look for the first ASCII non-space byte
+	start := 0
+	for ; start < len(s); start++ {
+		c := s[start]
+		if c >= utf8.RuneSelf {
+			// If we run into a non-ASCII byte, fall back to the
+			// slower unicode-aware method on the remaining bytes
+			return TrimFunc(s[start:], unicode.IsSpace)
+		}
+		if asciiSpace[c] == 0 {
+			break
+		}
+	}
+
+	// Now look for the first ASCII non-space byte from the end
+	stop := len(s)
+	for ; stop > start; stop-- {
+		c := s[stop-1]
+		if c >= utf8.RuneSelf {
+			return TrimFunc(s[start:stop], unicode.IsSpace)
+		}
+		if asciiSpace[c] == 0 {
+			break
+		}
+	}
+
+	// At this point s[start:stop] starts and ends with an ASCII
+	// non-space bytes, so we're done. Non-ASCII cases have already
+	// been handled above.
+	return s[start:stop]
 }
 
 // TrimPrefix returns s without the provided leading prefix string.