Command line traceur will now invoke the interpreter if no out param is passed

Command line traceur will now invoke the interpreter if no out param is passed
in

BUG=https://code.google.com/p/traceur-compiler/issues/detail?id=220
TEST=None

Committed: https://code.google.com/p/traceur-compiler/source/detail?r=fa7c011

[usrbincc, 2013-03-15 14:58:04]

Mostly looks okay. The only issues are with the arg handling and needing
the 'require' to make compiler.js work standalone.

https://codereview.appspot.com/7810043/diff/4001/src/node/command.js
File src/node/command.js (right):

https://codereview.appspot.com/7810043/diff/4001/src/node/command.js#newcode38
src/node/command.js:38: flags.option('--traceur-options', 'xxxxx');
flags.option('--traceur-options <OPTIONS>', 'specify feature options');

I'm wondering about this, though. You can't pass '--traceur-options' in
the hypothetical '#!/usr/bin/env traceur' case.

It's possible for '#!/usr/bin/traceur --traceur-options=opt1,opt2=false'
but it's unlikely traceur can reliably get to a standard location on all
systems.

Hypothetical at the moment, since this code doesn't handle shebang yet.

----

On the other hand, I'm not sure this will ever see common use, since in
the normal case, you can just specify args directly.

  ./traceur --strict-semicolons --block-binding file.js

Maybe just remove '--traceur-options' and implement 'Options:' in a
follow-up?

https://codereview.appspot.com/7810043/diff/4001/src/node/command.js#newcode40
src/node/command.js:40: console.log(arguments);
Noting debug code just in case.

https://codereview.appspot.com/7810043/diff/4001/src/node/command.js#newcode75
src/node/command.js:75: flags.parse(process.argv);
A little gotcha with passing args on to the script:

  # compiles instead of interpreting
  ./traceur interp-test.js --out out.js
  # this works
  ./traceur -- interp-test.js --out out.js

'--' works, but most interpreters I know handle this without
needing help. Probably just ignore for now, since this cannot be
separated from the fact that we use Commander.js .

https://codereview.appspot.com/7810043/diff/4001/src/node/compiler.js
File src/node/compiler.js (left):

https://codereview.appspot.com/7810043/diff/4001/src/node/compiler.js#oldcode30
src/node/compiler.js:30: require('./traceur.js');
Will compiler.js ever be used separately from command.js? If so, this
still needs to be in here. According to node docs, this should only get
executed once, even if you 'require' several times, so it shouldn't hurt
to leave it in.

https://codereview.appspot.com/7810043/diff/4001/src/node/compiler.js
File src/node/compiler.js (right):

https://codereview.appspot.com/7810043/diff/4001/src/node/compiler.js#newcode91
src/node/compiler.js:91: inlineAndCompile(includes.slice(current, current + 1),
{}, reporter,
Not sure if compiler.js will ever need to pass any flags, but just
something to note.

https://codereview.appspot.com/7810043/diff/4001/src/node/interpreter.js
File src/node/interpreter.js (left):

https://codereview.appspot.com/7810043/diff/4001/src/node/interpreter.js#oldc...
src/node/interpreter.js:31: var argv = process.argv.slice(1);
Note that process.argv still contains any options passed to the
interpreter. Easiest thing would be to just use 'flags.args' from
commander.js, the only caveat being that you need to prepend 'traceur'.
Up to you on that, but I have graciously provided my opinion in the
code comment following this one.

https://codereview.appspot.com/7810043/diff/4001/src/node/interpreter.js#oldc...
src/node/interpreter.js:32: argv[0] = 'traceur';
I know this mirrors node convention:
  ['node', 'file.js', 'arg1', 'arg2']
  ['traceur', 'file.js', 'arg1', 'arg2']
but I still prefer the bash and python convention:
  ['file.js', 'arg1', 'arg2']
though ruby and perl inexplicably do:
  ['arg1', 'arg2']

Couldn't resist a mini-rant. But this is node convention, so there is
some logic to it.

[arv, 2013-03-18 14:45:28]

PTAL

https://codereview.appspot.com/7810043/diff/4001/src/node/command.js
File src/node/command.js (right):

https://codereview.appspot.com/7810043/diff/4001/src/node/command.js#newcode38
src/node/command.js:38: flags.option('--traceur-options', 'xxxxx');
On 2013/03/15 14:58:04, usrbincc wrote:
> flags.option('--traceur-options <OPTIONS>', 'specify feature options');
> 
> I'm wondering about this, though. You can't pass '--traceur-options' in
> the hypothetical '#!/usr/bin/env traceur' case.
> 
> It's possible for '#!/usr/bin/traceur --traceur-options=opt1,opt2=false'
> but it's unlikely traceur can reliably get to a standard location on all
> systems.
> 
> Hypothetical at the moment, since this code doesn't handle shebang yet.
> 
> ----
> 
> On the other hand, I'm not sure this will ever see common use, since in
> the normal case, you can just specify args directly.
> 
>   ./traceur --strict-semicolons --block-binding file.js
> 
> Maybe just remove '--traceur-options' and implement 'Options:' in a
> follow-up?

I think I forgot to upload a new version.

My current plan is to not include this in this patch. We can and should revisit
how to pass along params to traceur, node and v8 at some point.

https://codereview.appspot.com/7810043/diff/4001/src/node/command.js#newcode75
src/node/command.js:75: flags.parse(process.argv);
On 2013/03/15 14:58:04, usrbincc wrote:
> A little gotcha with passing args on to the script:
> 
>   # compiles instead of interpreting
>   ./traceur interp-test.js --out out.js
>   # this works
>   ./traceur -- interp-test.js --out out.js
> 
> '--' works, but most interpreters I know handle this without
> needing help. Probably just ignore for now, since this cannot be
> separated from the fact that we use Commander.js .

Lets try to track all these gotchas in new bugs. It is pretty lame that I cannot
use traceur to interpret an es6 file that takes an --out command line flag.

https://codereview.appspot.com/7810043/diff/4001/src/node/compiler.js
File src/node/compiler.js (left):

https://codereview.appspot.com/7810043/diff/4001/src/node/compiler.js#oldcode30
src/node/compiler.js:30: require('./traceur.js');
On 2013/03/15 14:58:04, usrbincc wrote:
> Will compiler.js ever be used separately from command.js? If so, this
> still needs to be in here. According to node docs, this should only get
> executed once, even if you 'require' several times, so it shouldn't hurt
> to leave it in.

Good point. Putting it back.

https://codereview.appspot.com/7810043/diff/4001/src/node/interpreter.js
File src/node/interpreter.js (left):

https://codereview.appspot.com/7810043/diff/4001/src/node/interpreter.js#oldc...
src/node/interpreter.js:32: argv[0] = 'traceur';
On 2013/03/15 14:58:04, usrbincc wrote:
> I know this mirrors node convention:
>   ['node', 'file.js', 'arg1', 'arg2']
>   ['traceur', 'file.js', 'arg1', 'arg2']
> but I still prefer the bash and python convention:
>   ['file.js', 'arg1', 'arg2']
> though ruby and perl inexplicably do:
>   ['arg1', 'arg2']
> 
> Couldn't resist a mini-rant. But this is node convention, so there is
> some logic to it.

I want us to be able to replace "node foo.js" with "traceur foo.js" so I don't
think we have much of an option here.

[usrbincc, 2013-03-18 16:52:38]

LGTM

I'll see about making bug reports for the arg-handling bugs (As far as I
can tell, there are only two, really).

Just to confirm, should these produce identical results for ES5 files?
(Barring any pathological cases)

  ./traceur file.js args

  node file.js args

  ./traceur --out file.out.js file.js
  node file.out.js args

https://codereview.appspot.com/7810043/diff/4001/src/node/command.js
File src/node/command.js (right):

https://codereview.appspot.com/7810043/diff/4001/src/node/command.js#newcode38
src/node/command.js:38: flags.option('--traceur-options', 'xxxxx');
> My current plan is to not include this in this patch. We can and should
revisit
> how to pass along params to traceur, node and v8 at some point.

First thing (for whenever it's revisited) is probably to decide what
interface you would like 'traceur' to have for passing params to each
part, in both the command-line and shebang cases. And then working from
that, figure out how to do it (or if it's practical to do at all).

https://codereview.appspot.com/7810043/diff/4001/src/node/interpreter.js
File src/node/interpreter.js (left):

https://codereview.appspot.com/7810043/diff/4001/src/node/interpreter.js#oldc...
src/node/interpreter.js:32: argv[0] = 'traceur';
On 2013/03/18 14:45:28, arv-chromium wrote:
> On 2013/03/15 14:58:04, usrbincc wrote:
> > I know this mirrors node convention:
> >   ['node', 'file.js', 'arg1', 'arg2']
> >   ['traceur', 'file.js', 'arg1', 'arg2']
> > but I still prefer the bash and python convention:
> >   ['file.js', 'arg1', 'arg2']
> > though ruby and perl inexplicably do:
> >   ['arg1', 'arg2']
> > 
> > Couldn't resist a mini-rant. But this is node convention, so there is
> > some logic to it.
> 
> I want us to be able to replace "node foo.js" with "traceur foo.js" so I don't
> think we have much of an option here.

Makes sense.

[arv, 2013-03-18 20:23:08]

Committed patchset #6 manually as rfa7c011 (presubmit successful).