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[ 1 to 5]
|> map ->
  * x: it
    y: it * 2
  * x: it
    y: it * it

Returns:

[{"x":1,"y":1},{"x":2,"y":4},{"x":3,"y":9}]

Expected:

[[{"x":1,"y":2},{"x":1,"y":1}],[{"x":2,"y":4},{"x":2,"y":4}],[{"x":3,"y":6},{"x":3,"y":9}]]

Ugly workaround:

[ 1 to 3]
|> map ->
    res =
      * x: it
        y: it * 2
      * x: it
        y: it * it

Am I misunderstanding something about the syntax for object list literals? Is it only supported in assignments?

Thanks.

Oct 21 '15 09:10 atifaziz

I agree that in both cases your code should compile to an (array of dicts) literal.

Minimal breaking example:

a = 
  * A: 1
    B: 2
  * C: 3
    D: 4
f = ->
  * A: 1
    B: 2
  * C: 3
    D: 4

Seems that lexer returns the same for both, but AST for latter lacks Arr. Looking into AST.

Jan 07 '16 21:01 summivox

Starting to believe it's fundamental to how current parser is structured.

Meanwhile, a marginally better fix for your code:

[ 1 to 5]
|> map -> return
  * x: it
    y: it * 2
  * x: it
    y: it * it

Jan 07 '16 22:01 summivox

Yeah, it indeed is how the lexer works... A bit subpar but hey...

Jan 07 '16 22:01 vendethiel

I realized that function body is an implicit list, so implicit return of last item of the list is actually the correct semantics... Can't really blame lexer for this :wink:

Jan 07 '16 22:01 summivox

@summivox Thanks for the return hint. Does read better than having an unused assignment as in the original workaround I had used.

Jan 18 '16 10:01 atifaziz

Another way:

f = -> []=
  * A: 1
    B: 2
  * C: 3
    D: 4

Feb 11 '16 11:02 pepkin88

That's what * compiles to

Feb 11 '16 11:02 vendethiel

For the record: []= is just a destructuring assignment without stating a variable, i.e. "anonymous assignment". So it's an equivalent to the workaround with a temporary variable from the first post.

Feb 11 '16 12:02 pepkin88

I guess this is the same issue I've just come across:

table1 =
  * id: 1
    name: 'george'
  * id: 2
    name: 'mike'
  * id: 3
    name: 'donald'
console.log do
  * id: 1
    name: 'george'
  * id: 2
    name: 'mike'
  * id: 3
    name: 'donald'

// Generated by LiveScript 1.3.1
(function(){
  var table1;
  table1 = [
    {
      id: 1,
      name: 'george'
    }, {
      id: 2,
      name: 'mike'
    }, {
      id: 3,
      name: 'donald'
    }
  ];
  console.log({
    id: 1,
    name: 'george'
  }, {
    id: 2,
    name: 'mike'
  }, {
    id: 3,
    name: 'donald'
  });
}).call(this);

Function calls using the do keyword are not correctly converting arrays.

Jun 17 '16 14:06 johngeorgewright

@johngeorgewright Nothing incorrect about that! do (in this usage) means ‘treat the following as individual arguments’; * means ‘here begins a new structure’. * does not mean ‘I am an item in an array’ (although lots of people seem to assume that is what it means, and perhaps it should change).

Jun 17 '16 14:06 rhendric

Ah. Apologies, so I need to choose 1 of the following:

table1 =
  * id: 1
    name: 'george'
  * id: 2
    name: 'mike'
  * id: 3
    name: 'donald'

console.log table

... or ...

console.log [
  {
    id: 1
    name: 'mike'
  },
  {
    id: 2
    name: 'mike'
  },
  {
    id: 3
    name: 'donald'
  }
]

Jun 17 '16 14:06 johngeorgewright

Or

console.log [
  * id: 1
    name: 'george'
  * id: 2
    name: 'mike'
  * id: 3
    name: 'donald'
]

Jun 17 '16 14:06 rhendric

Or

console.log []=
  * id: 1
    name: 'george'
  * id: 2
    name: 'mike'
  * id: 3
    name: 'donald'

Jun 17 '16 14:06 pepkin88

@rhendric I believe that this behavior (func do then (implicit-list)) should not change. It has become a "feature". We need better documentation that explains the semantics of * (hopefully without touching too much compiler internals).

Jun 17 '16 17:06 summivox