Guard the use of write in the implementation of print.

Guard the use of write in the implementation of print.


R=efortuna@google.com
BUG=
TEST=

Committed: https://code.google.com/p/dart/source/detail?r=9417

[Emily Fortuna, 2012-07-05 11:46:42]

lgtm with comments

https://chromiumcodereview.appspot.com/10694089/diff/1/lib/compiler/implement...
File lib/compiler/implementation/lib/js_helper.dart (right):

https://chromiumcodereview.appspot.com/10694089/diff/1/lib/compiler/implement...
lib/compiler/implementation/lib/js_helper.dart:373: bool hasDartPrint =
JS('bool', @'typeof dartPrint == "function"');
nit: the style guide suggests having leaving variables untyped if they're local
and it's obvious, but if you prefer it this way, I can accept that too.

https://chromiumcodereview.appspot.com/10694089/diff/1/lib/compiler/implement...
lib/compiler/implementation/lib/js_helper.dart:379: bool hasConsole = JS('bool',
@'typeof console == "object"');
nit: personally I'd write this as 
if (hasDartPrint) {
       JS('void', @'dartPrint(#)', string);
} else if(JS('bool', @'typeof console == "object"')) {
      JS('void', @'console.log(#)', string);
} else if (JS('bool', @'typeof write == "function"')) {
etc

just to make the control flow a little clearer, but this is fine, too if you
prefer.

[kasperl, 2012-07-05 11:49:03]

Thanks, Emily!

https://chromiumcodereview.appspot.com/10694089/diff/1/lib/compiler/implement...
File lib/compiler/implementation/lib/js_helper.dart (right):

https://chromiumcodereview.appspot.com/10694089/diff/1/lib/compiler/implement...
lib/compiler/implementation/lib/js_helper.dart:373: bool hasDartPrint =
JS('bool', @'typeof dartPrint == "function"');
On 2012/07/05 11:46:42, Emily Fortuna wrote:
> nit: the style guide suggests having leaving variables untyped if they're
local
> and it's obvious, but if you prefer it this way, I can accept that too.

Done.

https://chromiumcodereview.appspot.com/10694089/diff/1/lib/compiler/implement...
lib/compiler/implementation/lib/js_helper.dart:379: bool hasConsole = JS('bool',
@'typeof console == "object"');
On 2012/07/05 11:46:42, Emily Fortuna wrote:
> nit: personally I'd write this as 
> if (hasDartPrint) {
>        JS('void', @'dartPrint(#)', string);
> } else if(JS('bool', @'typeof console == "object"')) {
>       JS('void', @'console.log(#)', string);
> } else if (JS('bool', @'typeof write == "function"')) {
> etc
> 
> just to make the control flow a little clearer, but this is fine, too if you
> prefer.

In this case, I think the JS expressions are a bit obscure so I prefer to be
able to "name" them. With the extra local variables the nesting gets a bit
annoying which is why I went for the variant with explicit returns.