text/scanner: rename AllowNumberbars to AllowDigitSeparators

Fixes #32661.

Change-Id: I32dc4e7b276b95ac2e87a384caa6c48702368d05
Reviewed-on: https://go-review.googlesource.com/c/go/+/183077Reviewed-by: Andrew Bonventre <andybons@golang.org>

src/text/scanner/scanner.go

@@ -67,8 +67,8 @@ const (
 	ScanRawStrings       = 1 << -RawString
 	ScanComments         = 1 << -Comment
 	SkipComments         = 1 << -skipComment          // if set with ScanComments, comments become white space
-	AllowNumberbars = 1 << -allowNumberbars // if set, number literals may contain underbars as digit separators
-	GoTokens        = ScanIdents | ScanFloats | ScanChars | ScanStrings | ScanRawStrings | ScanComments | SkipComments | AllowNumberbars
+	AllowDigitSeparators = 1 << -allowDigitSeparators // if set, number literals may contain underscores as digit separators
+	GoTokens             = ScanIdents | ScanFloats | ScanChars | ScanStrings | ScanRawStrings | ScanComments | SkipComments | AllowDigitSeparators
 )
 
 // The result of Scan is one of these tokens or a Unicode character.
@@ -84,7 +84,7 @@ const (
 
 	// internal use only
 	skipComment
-	allowNumberbars
+	allowDigitSeparators
 )
 
 var tokenString = map[rune]string{
@@ -363,8 +363,8 @@ func lower(ch rune) rune     { return ('a' - 'A') | ch } // returns lower-case c
 func isDecimal(ch rune) bool { return '0' <= ch && ch <= '9' }
 func isHex(ch rune) bool     { return '0' <= ch && ch <= '9' || 'a' <= lower(ch) && lower(ch) <= 'f' }
 
-// digits accepts the sequence { digit } (if AllowNumberbars is not set)
-// or { digit | '_' } (if AllowNumberbars is set), starting with ch0.
+// digits accepts the sequence { digit } (if AllowDigitSeparators is not set)
+// or { digit | '_' } (if AllowDigitSeparators is set), starting with ch0.
 // If base <= 10, digits accepts any decimal digit but records
 // the first invalid digit >= base in *invalid if *invalid == 0.
 // digits returns the first rune that is not part of the sequence
@@ -374,7 +374,7 @@ func (s *Scanner) digits(ch0 rune, base int, invalid *rune) (ch rune, digsep int
 	ch = ch0
 	if base <= 10 {
 		max := rune('0' + base)
-		for isDecimal(ch) || ch == '_' && s.Mode&AllowNumberbars != 0 {
+		for isDecimal(ch) || ch == '_' && s.Mode&AllowDigitSeparators != 0 {
 			ds := 1
 			if ch == '_' {
 				ds = 2
@@ -385,7 +385,7 @@ func (s *Scanner) digits(ch0 rune, base int, invalid *rune) (ch rune, digsep int
 			ch = s.next()
 		}
 	} else {
-		for isHex(ch) || ch == '_' && s.Mode&AllowNumberbars != 0 {
+		for isHex(ch) || ch == '_' && s.Mode&AllowDigitSeparators != 0 {
 			ds := 1
 			if ch == '_' {
 				ds = 2

src/text/scanner/scanner_test.go

@@ -887,7 +887,7 @@ func TestIssue30320(t *testing.T) {
 		{"foo0/12/0/5.67", "0 12 0 5 67", ScanInts},
 		{"xxx1e0yyy", "1 0", ScanInts},
 		{"1_2", "1 2", ScanInts}, // don't consume _ as part of a number if not explicitly enabled
-		{"1_2", "1_2", ScanInts | AllowNumberbars},
+		{"1_2", "1_2", ScanInts | AllowDigitSeparators},
 		{"xxx1.0yyy2e3ee", "1 0 2 3", ScanInts},
 		{"xxx1.0yyy2e3ee", "1.0 2e3", ScanFloats},
 	} {