Implement Polymorphism

[LemonHX]

draft:

a:int = 10
a:string = "string"

it will not throw type fail exception, instead a will be two instance one is typed int the other will be typed string

f = (a:int) -> int a
f = (a:string) -> string a

f now also has two instance

b:int = f(a) # will use the instance int -> int
b:string = f(a) # will use the instance string -> string

b = f(a)

but what if the type of b is not specified?
for simplicity just use the first type it matches.

[LemonHX]

better design
add keyword dyn

dyn a = 1 # dyn [number]
dyn a = "string" # dyn [string]
c = (x:number) -> number x
c(a) # number

rewrite

a = {}
a["number"] = 1
a["string"] = "string"
c = (x) x
c(a["number"])

just a syntax sugar for map

dyn f = (x:number) -> number {
    if x.lt(3)
        x.add(1).f
    else
        x
}

f = {}
f["number->number"] = (f)(x) if x.lt(3) x.add(1).f else x
f["number->number"] = f["number->number"](f["number->number"])

rewrite
ignore dyn rewrite let rec