Major syntax rework

[wongjiahau]

[

| 123 

// tagged union
| Shape = (
    choice 
        Circle(# radius(Float))
        Square(# side(Float))
        Rectangle(# width(Float).height(Float))
)

// object alias
| Person = (# name(String).age(Float))

// object constsruction
| p = (Person name("Wong").age(123.0))

| p name

| Shape Rectangle(# width(12.0).height(14.0)) area

// case matching
| (Shape s) area = (
    s
        if(_ Circle(c)) then
            (c radius square *(3.14))

        if(_ Square(s)) then 
            (s side square)

        if(_ Rectangle(r)) then 
            (r width *(r height))
)

// Mono func
| (Int n) square -> (Int) = (n ^(2))

// 2-arg-func 
| (Int x) plus(Int y) = (x +(y))

// 3-arg-func 
| (Knight k) attack(Monster m).with(Weapon w) = (undefined) 

// 4-arg func
| [|A Type] => (List of(A) xs) replace(Int startIndex).to(Int endIndex).with(A value) ->(List of(A)) = (undefined)

]