code review 6225047: go/scanner: strip carriage returns from commments

go/scanner: strip carriage returns from commments

Also:
- cleaned up and simplified TestScan
- added tests for comments containing carriage returns

Fixes issue 3647.

[gri, 2012-05-22 00:40:31]

Hello golang-dev@googlegroups.com,

I'd like you to review this change to
https://code.google.com/p/go

[rsc, 2012-05-22 03:28:17]

I think the CR change looks good, but I'd prefer not to change the scanner
semantics.  Updating the docs is the safer course.  We struggled with the same
issue with runtime.Callers (arguably a more significant change) and ended up
doing the same thing: update the docs to describe the (not entirely intended) Go
1 behavior.

http://codereview.appspot.com/6225047/diff/6003/src/pkg/go/scanner/scanner.go
File src/pkg/go/scanner/scanner.go (right):

http://codereview.appspot.com/6225047/diff/6003/src/pkg/go/scanner/scanner.go...
src/pkg/go/scanner/scanner.go:579: fallthrough
I think it is too late to change this.  The code does what it does, and it
returns (not unreasonably) the string "break" "continue" "fallthrough" or
"return" for these cases.  Taking that away now seems like a violation of the
API contract.  I think the code should stay as is and the documentation should
be updated.

[gri, 2012-05-22 16:32:53]

Hello rsc@golang.org (cc: golang-dev@googlegroups.com),

Please take another look.

[rsc, 2012-05-22 17:02:29]

LGTM

[gri, 2012-05-22 17:03:58]

*** Submitted as http://code.google.com/p/go/source/detail?r=ef8ee411b23b ***

go/scanner: strip carriage returns from commments

Also:
- cleaned up and simplified TestScan
- added tests for comments containing carriage returns

Fixes issue 3647.

R=rsc
CC=golang-dev
http://codereview.appspot.com/6225047