Hello! I found a-b-c and a-b -c give different result. Anyone knows if this is following the language specification or not? a = 20 b = 19 c=3 pp! a-b -c pp! a-b-c gives a - (b - c) # => 4 (a - b) - c # => -2

Wow. First case definitely looks like a bug. Any language where a - b - c would become a - (b - c)?

The problem is that a-b -c becomes a - (b - c) while a-b-c becomes (a - b) - c. Spaces shouldn’t change the result.

BTW a = 20 b = 19 c=3 pp! a&-b &-c pp! a&-b&-c (a &- b) &- c # => -2 (a &- b) &- c # => -2

It’s a bug, please report it in GitHub. It’s hard to fix.

Fix here: https://github.com/crystal-lang/crystal/pull/9652

Great! I hope this will be included soon!

[image] makino: Anyone knows if this is following the language specification or not? The language specification for these things is “Try it in Ruby. If you get a different result than Ruby then it’s a bug”.

I ended up closing the PR because I’m not sure it’s the best way to fix it. You’ll have to hope someone else will fix it then.

Results of "a-b -c" and "a-b-c" different

Help & Support

asterite August 1, 2020, 11:20am 7

Meh, it’s very easy to fix.

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Results of "a-b -c" and "a-b-c" different

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