fix strings bug

fix strings bug

BUG: http://code.google.com/p/dart/issues/detail?id=313

Committed: https://code.google.com/p/dart/source/detail?r=1098

[Siggi Cherem (dart-lang), 2011-11-02 16:37:11]

TBR

[ahe, 2011-11-02 18:17:58]

I'm not sure I understand how this fixes the problem, but LGTM if it does :-)

http://codereview.chromium.org/8386036/diff/1/member.dart
File member.dart (right):

http://codereview.chromium.org/8386036/diff/1/member.dart#newcode1021
member.dart:1021: value = '"' + value.replaceAll('"', '\\"') + '"';
What happens with these strings:

"\""
'\\"'

[jimhug, 2011-11-03 00:57:21]

Can you help us understand why this change fixes the bug?

http://codereview.chromium.org/8386036/diff/1/member.dart
File member.dart (right):

http://codereview.chromium.org/8386036/diff/1/member.dart#newcode1021
member.dart:1021: value = '"' + value.replaceAll('"', '\\"') + '"';
This does seem to fix this issue - but I share Peter's puzzlement that this
works...

On 2011/11/02 18:17:58, ahe wrote:
> What happens with these strings:
> 
> "\""
> '\\"'

[Siggi Cherem (dart-lang), 2011-11-03 17:31:28]

http://codereview.chromium.org/8386036/diff/1/member.dart
File member.dart (right):

http://codereview.chromium.org/8386036/diff/1/member.dart#newcode1021
member.dart:1021: value = '"' + value.replaceAll('"', '\\"') + '"';
On 2011/11/03 00:57:21, jimhug wrote:
> This does seem to fix this issue - but I share Peter's puzzlement that this
> works...
> 
> On 2011/11/02 18:17:58, ahe wrote:
> > What happens with these strings:
> > 
> > "\""
> > '\\"'
> 

The issue is basically how we are representing strings as values. We tried to
preserve the original quotes in the value that it generates. Every compile-time
concatenation of strings is removing the quotes, concatenating the contents, and
putting the quotes back. 

Before this change, we weren't putting the quotes back.

Your examples will likely break right now, so I'll work on fixing that. I might
change the compiler to not include the quotes when parsing, or be more careful
about which quotes were used in val0/val1, and only escape strings when the
quotes differ.

[Jennifer Messerly, 2011-11-03 17:49:40]

http://codereview.chromium.org/8386036/diff/1/member.dart
File member.dart (right):

http://codereview.chromium.org/8386036/diff/1/member.dart#newcode1021
member.dart:1021: value = '"' + value.replaceAll('"', '\\"') + '"';
On 2011/11/03 17:31:28, sigmund wrote:
> On 2011/11/03 00:57:21, jimhug wrote:
> > This does seem to fix this issue - but I share Peter's puzzlement that this
> > works...
> > 
> > On 2011/11/02 18:17:58, ahe wrote:
> > > What happens with these strings:
> > > 
> > > "\""
> > > '\\"'
> > 
> 
> The issue is basically how we are representing strings as values. We tried to
> preserve the original quotes in the value that it generates. Every
compile-time
> concatenation of strings is removing the quotes, concatenating the contents,
and
> putting the quotes back. 
> 
> Before this change, we weren't putting the quotes back.
> 
> Your examples will likely break right now, so I'll work on fixing that. I
might
> change the compiler to not include the quotes when parsing, or be more careful
> about which quotes were used in val0/val1, and only escape strings when the
> quotes differ.

+1 on normalizing strings in the tokenizer, rather than keeping them as quoted
values everywhere. I suspect a lot of string handling code will become simpler.