prettier type printing

[alex-s168]

This is extremly unreadable:

Cons<Cons<Cons<SmartString+LMStruct+GlobalVariable+Sized+Tag::SmartString+Field::4<Array<U8,?>>+Field::3<Array<U8,?>>+Field::2<Array<U8,?>>+Field::1<Array<U8,?>>+CaseNumber<0>+Tag::SmartString+Tag::SmartString,Constant+Literal+U8+LMStruct+I64+I32+I16+U64+U32+U16+Sized>,Arrow<Nil,SmartString>>,Arrow<Cons<Array<Umbra,?>,t>,Umbra>+Arrow<Cons<t,Array<Umbra,?>>,Umbra>+Arrow<Cons<Array<base-type,?>,I64>,Array<base-type,?>>+Blob+Arrow<Cons<Array<base-type,?>,U64>,Array<base-type,?>>+Blob+Arrow<Cons<Vector<t>,Vector<t>>,t>+Arrow<Cons<List<x>,List<x>>,List<x>>+Arrow<Cons<S,S>,S>+Arrow<Cons<SmartString,U8>,SmartString>+Arrow<Cons<SmartString,SmartString>,SmartString>+Arrow<Cons<String,String>,String>+Arrow<Cons<F64,F64>,F64>+Blob+Arrow<Cons<I64,I64>,I64>+Blob+Arrow<Cons<U64,U64>,U64>+Blob+Arrow<Cons<I32,I32>,I32>+Blob+Arrow<Cons<U32,U32>,U32>+Blob+Arrow<Cons<I16,I16>,I16>+Blob+Arrow<Cons<U16,U16>,U16>+Blob+Arrow<Cons<I8,I8>,I8>+Blob+Arrow<Cons<U8,U8>,U8>+Blob+Arrow<Cons<L,L>,L>+Blob>

[andrew-johnson-4]

Some possible improvements

• put this into normal form before printing (can be done right now)
  • this is actually a bug that just needs to be fixed
• pretty print form for arrows, tuples, and cons (can be done right now)
• pretty print plural arrows (can be done right now)
• error message specialization (a little harder to do)

The first one is the biggest issue, because in normal form this becomes

Cons<Cons<Cons<SmartString,U8>,Arrow<Nil,SmartString>>,Arrow<Cons<Array<Umbra,?>,t>,Umbra>,Arrow<Cons<Array<base-type,?>,I64>,Array<base-type,?>>