Why does nim put the Export marker on the right side?

[javinyang]

    type
      MyType* = ref object
        a*: int32
        b*: int32
        c*: int32
    
    proc myProc*() = discard
    
    
    Run

I don't understand why it is placed on the right side. Is there any reason for 
this design? Feel good on the left side. 
    
    
    type
      *MyType = ref object
        *a: int32
        *b: int32
        *c: int32
    
    proc myProc*() = discard
    
    
    Run

And why is the following not allowed? 
    
    
    dumpTree:
      mytype MyType:
        a*: int
    
    
    Run

Error: expression expected, but found ':'