Lexer: Backslash not supported in import or export statements

[eugenet8k]

This works:

import my_module from 'my/path/nodule'

This doesn't work:

import my_module
  from 'my/path/nodule'

[stdin]:2:1: error: unexpected indentation
  from 'my/path/nodule'

This doesn't work as well:

import my_module \
  from 'my/path/nodule'

[stdin]:1:8: error: unexpected implicit function call
import my_module \
       ^^^^^^^^^

As a result, there is no way to wrap long imports into few lines.

[eugenet8k]

The only workaround I could found is to use backticks. This works:

`import my_module
  from 'my/path/nodule'`

[GeoffreyBooth]

The first “doesn’t work” example isn’t really a bug; CoffeeScript is a significant-whitespace language, so in the absence of something that implies that a statement should continue onto the next line, a line return is treated as the end of a statement. The second example, however, should work; the backslash there should allow a line continuation.

@zdenko, this looks to be a sibling to #4861? Could we generalize that fix to all of the seen* flags in the lexer?

[zdenko]

@GeoffreyBooth, yes it looks very much like #4861.
I'll take a look into this later this weekend and try to come up with a robust solution which would also cover other similar cases.