`from` is now a reserved word in for loop declarations

[IvanVergiliev]

Apparently the addition of the for...from loop breaks code with variables called from. Obviously this can't be fixed, but it should at least be documented as a breaking change in the Changelog.

Also, I had a hard time finding a set of all reserved words in CoffeeScript - this would also be a useful addition, IMO.

[GeoffreyBooth]

from is only a keyword in the context of an import/export statement or for loop. I can use it as a variable: http://coffeescript.org/#try:from%20%3D%202

Can you post example code that worked in 1.11.1 but broke in 1.12.0?

[IvanVergiliev]

lines = [
  {from: 0, to: 10}
  {from: 3, to: 17}
]

for {from, to} in lines
  console.log from

I also noticed that I can use it as a variable name sometimes. Apparently this case breaks because it's part of a for loop.

[GeoffreyBooth]

@atg, do you feel like looking into this?

[vendethiel]

Oh, it's just a really old thing the compiler's lexer does. That's just @seenFor parsing stuff differently between a for and a from/of/in...

[distracteddev]

@GeoffreyBooth Quick question, if adding "from" support was a breaking change, why did the project decide to publish it without a major version bump? Should I expect this project to respect semver in the future?

[vendethiel]

@distracteddev where did it say it was "clearly a breaking change"? @GeoffreyBooth even offered to look at 1.12 regressions.

(Also, https://gist.github.com/jashkenas/cbd2b088e20279ae2c8e)

[distracteddev]

My bad, assumed adding "from" support was known to be a breaking change. I see now that this wasn't intended to be the case.

Thanks for the note on semver.

[GeoffreyBooth]

Fixed in #4393. We will be releasing 1.12.1 soon.