Fixed escaping of const values

Fixed escaping of const values
http://code.google.com/p/dart/issues/detail?id=323

Committed: https://code.google.com/p/dart/source/detail?r=2001

[Jennifer Messerly, 2011-12-01 22:54:34]

tbr

[Siggi Cherem (dart-lang), 2011-12-01 23:05:08]

lgtm

[jimhug, 2011-12-02 00:16:00]

I hate to be nit picking, but I think there are some minor holes in this
rewrite.  I'd like to get this escape done right now so that we don't ever have
to worry about it again.

http://codereview.chromium.org/8773021/diff/2002/frog/value.dart
File frog/value.dart (right):

http://codereview.chromium.org/8773021/diff/2002/frog/value.dart#newcode743
frog/value.dart:743: return text.replaceAll('/*', '/ *').replaceAll('*/', '*
/');
I think you need two more spaces to make this bullet proof.  I'd strongly
suggest just using ' * ' as the replacement.  With your current version, I think
these would break in the right/wrong positions:
/*/   */*

http://codereview.chromium.org/8773021/diff/2002/tests/language/src/ConstEsca...
File tests/language/src/ConstEscapeFrogTest.dart (right):

http://codereview.chromium.org/8773021/diff/2002/tests/language/src/ConstEsca...
tests/language/src/ConstEscapeFrogTest.dart:2: final Bar<Foo> bar = const Bar/*
comment here use to trigger bug 323 */();
Minor TODO: Add some simple cases to this that would have failed if you'd used a
simple scheme, i.e. /** comment **/ or similar.

[Jennifer Messerly, 2011-12-02 00:24:22]

http://codereview.chromium.org/8773021/diff/2002/frog/value.dart
File frog/value.dart (right):

http://codereview.chromium.org/8773021/diff/2002/frog/value.dart#newcode743
frog/value.dart:743: return text.replaceAll('/*', '/ *').replaceAll('*/', '*
/');
On 2011/12/02 00:16:00, jimhug wrote:
> I think you need two more spaces to make this bullet proof.  I'd strongly
> suggest just using ' * ' as the replacement.  With your current version, I
think
> these would break in the right/wrong positions:
> /*/   */*
> 

with the double replace,
> "/*/".replace('/*', '/ *').replace('*/', '* /')
"/ * /"
> "*/*".replace('/*', '/ *').replace('*/', '* /')
"* / *"

I don't feel 100% confident though with any of these, short of killing all / and
* from the string. (Maybe we should just get rid of the const-comments. I'm not
sure they're really worth it. Some complexity in GlobalValue/EvaluatedValue
would go away too)