scanner: change package comment to be clearer about its functionality.
No semantic changes.
R=gri, rsc1
CC=golang-dev
https://golang.org/cl/1998045
diff --git a/src/pkg/scanner/scanner.go b/src/pkg/scanner/scanner.go
index a1aa109..0f864f8 100644
--- a/src/pkg/scanner/scanner.go
+++ b/src/pkg/scanner/scanner.go
@@ -2,15 +2,15 @@
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
-// A general-purpose scanner for UTF-8 encoded text. Takes an io.Reader
-// providing the source which then can be tokenized through repeated
-// calls to the Scan function. For compatibility with existing tools,
-// the NUL character is not allowed (implementation restriction).
+// A scanner and tokenizer for UTF-8-encoded text. Takes an io.Reader
+// providing the source, which then can be tokenized through repeated calls
+// to the Scan function. For compatibility with existing tools, the NUL
+// character is not allowed (implementation restriction).
//
-// By default, a Scanner skips white space and comments and
-// recognizes literals as defined by the Go language spec.
-// It may be customized to recognize only a subset of those
-// literals and to recognize different white space characters.
+// By default, a Scanner skips white space and Go comments and recognizes all
+// literals as defined by the Go language specification. It may be
+// customized to recognize only a subset of those literals and to recognize
+// different white space characters.
//
// Basic usage pattern:
//
