type Slider = {
disabled: &bool,
value: &f64,
min: &f64,
max: &f64,
step: &[f64, null],
on_change: &fn(v: f64) -> Any,
on_release: &fn(e: null) -> Any,
width: &Length,
height: &[f64, null]
};
val slider: fn(
?#min: &f64,
?#max: &f64,
?#step: &[f64, null],
?#on_change: fn(v: f64) -> Any,
?#on_release: fn(e: null) -> Any,
?#width: &Length,
?#height: &[f64, null],
?#disabled: &bool,
value: &f64
) -> Widget