Hashes

In 0.39.0 version Stylus got hash objects.

Define

You can define a hash using the curly braces and colons to divide the keys and values:

foo = {
  bar: baz,
  baz: raz
}

the keys should be either proper idents or strings:

foo = {
  bar: baz,
  'baz': raz,
  '0': raz
}

When you already have a hash, you can set its values using brackets and strings inside:

foo = {}
foo['bar'] = baz
foo['baz'] = raz

Note that while you can’t use variables or interpolations in curly braces defines, you can use variables inside brackets:

foo = {}
bar = 'baz'
foo[bar] = raz

foo.baz
// => raz

Getters

For retrieving values from hashes you can use the dot for idents:

foo = { bar: "baz" }

foo.bar
// => "baz"

Or brackets with strings for anything:

foo = { "%": 10 }
baz = "%"

foo[baz]
// => 10

You can use any combinations you want:

foo = {
  bar: {
    baz: {
      raz: 10px
    }
  }
}

qux = "raz"
foo["bar"].baz[qux]
// => 10px

Interpolation

Hashes used inside an interpolation would output the content of the hashes as CSS (without almost any Stylus features though):

foo = {
  width: 10px,
  height: 20px,
  '&:hover': {
    padding: 0

  }
}

.bar
  {foo}

// => .bar {
//      width: 10px;
//      height: 20px;
//    }
//    .bar:hover {
//      padding: 0;
//    }

Other stuff

You can use other normal Stylus stuff with hashes, like length():

foo = { bar: 'a', baz: 'b' }

length(foo)
// => 2

You can iterate through hashes with optional key param:

foo = { width: 10px, height: 20px }

for key, value in foo
  {key}: value

// => width: 10px;
//    height: 20px;

You can check existence of a key in hash using in:

foo = { bar: 10px}

bar in foo
// => true

baz in foo
// => false

You can get keys or values of the hash using corresponding bifs:

foo = { bar: 'a', baz: 'b' }

keys(foo)
// => 'bar' 'baz'

values(foo)
// => 'a' 'b'

You can remove a key from the hash using remove bif:

obj = { foo: 1, bar: 2 }
remove(obj, 'foo')
// => {"bar":"(2)"}

And you can use merge (aliased as extend) to merge hashes:

obj = {
  foo: 'foo'
  bar: 'bar'
}

obj2 = {
  baz: 'baz'
}

merge(obj, obj2)
// => {"foo":"('foo')","bar":"('bar')","baz":"('baz')"}