For 1-byte strings we don't need the full power of UTF-8 conversion with
support for 3 and 4-byte sequences and reassembly of UTF-16 surrogate pairs.
This optimization was originally intended to improve the reverse-complement
benchmark. It also seems to have a positive effect (ca. 1% on average) on
dart2js.
After implementing this it doesn't seem worth having a special case in
ToCString for ASCII strings. That special case would allocate the string twice
for all Latin1 strings, which feels unfortunate.
R=vegorov@google.com
Bug:
Change-Id: If852f3ecb4e06118da8357cfa2c843ad0df0edb9
Reviewed-on: https://dart-review.googlesource.com/8920
Commit-Queue: Erik Corry <erikcorry@google.com>
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
compatible with webkit and will allow for easy externalization of
strings. One byte strings are retained for pure ASCII strings.
(The language specification was changed recently to reflect this as
follows "A string is a sequence of UTF-16 code units").
- Remove four byte string class and all references to it.
- Rename some of the string functions in Dart API to make them
consistent and better describe the underlying functionality
Dart_NewString => Dart_NewStringFromCString
Dart_NewString8 => Dart_NewStringFromUTF8
Dart_NewString16 => Dart_NewStringFromUTF16
Dart_NewString32 => Dart_NewStringFromUTF32
Dart_NewExternalString8 => Dart_NewExternalUTF8String
Dart_NewExternalString16 => Dart_NewExternalUTF16String
Dart_NewExternalString32 => Dart_NewExternalUTF32String
Dart_StringGet8 => Dart_StringToUTF8
Dart_StringGet16 => Dart_StringToUTF16
Dart_StringToCString => Dart_StringToCString
Dart_IsString8 => Removed
Dart_IsString16 -> Removed
Dart_StringToBytes -> Removed
Dart_StringGet32 -> Removed
Review URL: https://codereview.chromium.org//11318018
git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@14357 260f80e4-7a28-3924-810f-c04153c831b5
In the past, characters in C strings were assumed to encode themselves
and when converting Dart strings to C strings characters were narrowed
to 8-bit values.
With this change, C strings are assumed to be UTF-8 encoded.
Converting a C string to a Dart string applies UTF-8 decoding and
converting a Dart string to a C string applies UTF-8 encoding.
Also part of this change are new methods to construct uninitialized
string objects and to copy string data.
BUG=5343358
Review URL: https://chromereviews.googleplex.com/3557012
git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@169 260f80e4-7a28-3924-810f-c04153c831b5
Erik Corry