Short-hand to append fields to a record

[julianhyde]

Add a short-hand to the language append fields to a record. For example, given

val emps = [
   {comm=0.0,deptno=20,empno=7369,ename="SMITH",hiredate="1980-12-16",
    job="CLERK",mgr=7902,sal=800.0},
   ... ]
: {comm:real, deptno:int, empno:int, ename:string, hiredate:string, job:string, mgr:int, sal:real} list;

suppose we wish to add a new column remuneration = comm + sal. Currently we would define a 'view' function

fun emps2 () =
  from e in emps
    yield {e.comm, e.deptno, e.empno, e.ename, e.hiredate, e.job,
      e.mgr, e.sal, remuneration = e.sal + e.comm};

but syntactic sugar such as the following would be helpful:

fun emps2 () =
  from e in emps
    yield {e.*, remuneration = e.sal + e.comm};

[julianhyde]

In order to derive a type for {e.*, remuneration = e.sal + e.com} we will need to add row polymorphism to our type system.