all: single space after period.

The tree's pretty inconsistent about single space vs double space
after a period in documentation. Make it consistently a single space,
per earlier decisions. This means contributors won't be confused by
misleading precedence.

This CL doesn't use go/doc to parse. It only addresses // comments.
It was generated with:

$ perl -i -npe 's,^(\s*// .+[a-z]\.)  +([A-Z]),$1 $2,' $(git grep -l -E '^\s*//(.+\.)  +([A-Z])')
$ go test go/doc -update

Change-Id: Iccdb99c37c797ef1f804a94b22ba5ee4b500c4f7
Reviewed-on: https://go-review.googlesource.com/20022
Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Dave Day <djd@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

src/bytes/bytes.go

@@ -164,7 +164,7 @@ func IndexRune(s []byte, r rune) int {
 
 // IndexAny interprets s as a sequence of UTF-8-encoded Unicode code points.
 // It returns the byte index of the first occurrence in s of any of the Unicode
-// code points in chars.  It returns -1 if chars is empty or if there is no code
+// code points in chars. It returns -1 if chars is empty or if there is no code
 // point in common.
 func IndexAny(s []byte, chars string) int {
 	if len(chars) > 0 {
@@ -188,8 +188,8 @@ func IndexAny(s []byte, chars string) int {
 }
 
 // LastIndexAny interprets s as a sequence of UTF-8-encoded Unicode code
-// points.  It returns the byte index of the last occurrence in s of any of
-// the Unicode code points in chars.  It returns -1 if chars is empty or if
+// points. It returns the byte index of the last occurrence in s of any of
+// the Unicode code points in chars. It returns -1 if chars is empty or if
 // there is no code point in common.
 func LastIndexAny(s []byte, chars string) int {
 	if len(chars) > 0 {
@@ -276,7 +276,7 @@ func Fields(s []byte) [][]byte {
 
 // FieldsFunc interprets s as a sequence of UTF-8-encoded Unicode code points.
 // It splits the slice s at each run of code points c satisfying f(c) and
-// returns a slice of subslices of s.  If all code points in s satisfy f(c), or
+// returns a slice of subslices of s. If all code points in s satisfy f(c), or
 // len(s) == 0, an empty slice is returned.
 // FieldsFunc makes no guarantees about the order in which it calls f(c).
 // If f does not return consistent results for a given c, FieldsFunc may crash.
@@ -352,12 +352,12 @@ func HasSuffix(s, suffix []byte) bool {
 
 // Map returns a copy of the byte slice s with all its characters modified
 // according to the mapping function. If mapping returns a negative value, the character is
-// dropped from the string with no replacement.  The characters in s and the
+// dropped from the string with no replacement. The characters in s and the
 // output are interpreted as UTF-8-encoded Unicode code points.
 func Map(mapping func(r rune) rune, s []byte) []byte {
 	// In the worst case, the slice can grow when mapped, making
-	// things unpleasant.  But it's so rare we barge in assuming it's
-	// fine.  It could also shrink but that falls out naturally.
+	// things unpleasant. But it's so rare we barge in assuming it's
+	// fine. It could also shrink but that falls out naturally.
 	maxbytes := len(s) // length of b
 	nbytes := 0        // number of bytes encoded in b
 	b := make([]byte, maxbytes)
@@ -697,7 +697,7 @@ func EqualFold(s, t []byte) bool {
 			return false
 		}
 
-		// General case.  SimpleFold(x) returns the next equivalent rune > x
+		// General case. SimpleFold(x) returns the next equivalent rune > x
 		// or wraps around to smaller values.
 		r := unicode.SimpleFold(sr)
 		for r != sr && r < tr {
@@ -709,6 +709,6 @@ func EqualFold(s, t []byte) bool {
 		return false
 	}
 
-	// One string is empty.  Are both?
+	// One string is empty. Are both?
 	return len(s) == len(t)
 }