New Issue: Output entire function signature when printing first class functions

19123, "ben-albrecht", "Output entire function signature when printing first class functions", "2022-01-26T16:02:18Z"

This is a follow-up issue to #13210

As of #13232, users can get the name of an fcf by casting it to a string:

proc fun(arg: int): int {
  return arg*2;

var fcf = fun;

// Name accessible through casting and/or printing:
const fcfName = fcf:string; // "fun()"
writeln(fcf); // fun()

It would be helpful to be able to print additional information about the function, for example:

  • argument names and argument types
  • return type
  • whether or not the function throws
  • where clauses

Basically, we'd want this to print the full signature of the function.

It may be valuable to introduce a field,, similar to fcf.retType and fcf.argTypes, so that users can still access the name alone without doing some string parsing. This is requested and discussed in #13285