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Re:Python with Braces by bluehex on Sunday February 09, 2014 @06:03PM (#7207827)
I don't see the ambiguity. Braces in expression position -> dict constructor. JavaScript is a fine example of how this is not a problem.
Re:Python with Braces by chewxy on Sunday February 09, 2014 @06:31PM (#7207978)
Actually, it is. It is very easy to confuse an object literal and a block in Javascript. In fact, in the book I am writing[0], I dedicate an entire chapter to using this ambiguity to write arsehole code. Here's another example[1]

[0] https://leanpub.com/underhandedjavascript or its alternate title: https://leanpub.com/jsinterviewquestions [1] Slide 21 (1-index): https://speakerdeck.com/chewxy/underhanded-javascript-how-to...

EDIT:

For those of you who do not want to click through my self promotional links, try this in your browser:

  {}[0] == true // false
  
  {}[1] == true // true
  
  !{}[0] == true // true
  
  !{}[1] == true // true
Re:Python with Braces by lowboy on Sunday February 09, 2014 @06:51PM (#7208073)
Do you have any non-contrived examples of confusing an object literal and a block?

Because as soon as you see this

    { identifier:
You know it's an object literal and not a block.
Re:Python with Braces by bcj on Sunday February 09, 2014 @07:02PM (#7208132)

    if foo == bar {
        baz(), lorem(), ipsum()
    }
could be:

    if foo == bar:
        baz(), lorem(), ipsum()
or:

    if foo == bar:
        {baz(), lorem(), ipsum()}
Admittedly, this code doesn't have a functional difference. With a bit more thought, I may be able to come up with code where that matters.