Out of order var declaration doesn't work with complex expressions

[andreypopp]

The following snippet:

a = b * 2
b = 1px
body
  margin a

results in

Error: test.styl:1
 > 1| a = b * 2
   2| b = 1px
   3| body
   4|   margin a

cannot perform b * 2

while

a = b
b = 1px
body
  margin a

compiles well (note the plain a = b instead of a = b * 2 in the first snippet).

[vendethiel]

it should not work at all, imho.

[Panya]

I'm suppose that you should declare variables before using them (like in other popular languages).

[vendethiel]

This doesn't make any sense. Why would that be allowed?

[kizu]

I guess, it's somewhat late to fix the current behavior (while someone could find it useful and it could break things for those), but it could be fixed (== the second example shouldn't work too) in 1.0 to make things more consistent and more logical.

[vendethiel]

Thank you.

[andreypopp]

@Nami-Doc see referenced issue, I'm trying to convert bootstrap from less to stylus and it seems that bootstrap declares vars out of order which I also find weird. Then I found an inconsistence.

@kizu agreed, it's better to get rid of inconsistent behaviour

[vendethiel]

Bootstrap not making sense certainly is sad, but not worth creating bad behaviors in a language

[kindaro]

Stylus is a declarative language. Not imperative. So, order of declarations within the same flat scope should not matter. Because we exile the notion of order of execution. It appears natural and obvious to me.

My 50 cent of example to this discussion:

  9 footer-height = 10vh
...
 24 footer
 25     position absolute
 26     height footer-height
 27     top 100vh - @height

-- Works.

  9 footer-height = 10vh
...
 24 footer
 25     position absolute
 26     top 100vh - @height
 27     height footer-height

-- cannot coerce null to unit

Kindly do consider considering this syntax correct.