Default procedure parameters are untyped

[liquidev]

For some reason, default parameters of procedures are not checked semantically (typed), which causes problems eg. when you want to get their type. Nim does not provide another mechanism of getting the type of a default parameter of a proc, getType and getTypeInst are the only way, but (obviously) they expect nnkSym as their parameter node's kind.

Example

import macros

var thing = 2
proc example(a = thing) =
  discard (a, thing)

macro echoImpl(x: typed) = echo x.getImpl.treeRepr

echoImpl(example)

Current Output

ProcDef
  Sym "example"
  Empty
  Empty
  FormalParams
    Empty
    IdentDefs
      Ident "a"
      Empty
      Ident "thing"
  Empty
  Empty
  DiscardStmt
    TupleConstr
      Sym "a"
      Sym "thing"

Expected Output

ProcDef
  Sym "example"
  Empty
  Empty
  FormalParams
    Empty
    IdentDefs
      Ident "a"
      Empty
      Sym "thing"  # ← basically, run a semantic check on this
  Empty
  Empty
  DiscardStmt
    TupleConstr
      Sym "a"
      Sym "thing"

Possible Solution

• Enable semantic checking on default params of procs.

Additional Information

$ nim -v
Nim Compiler Version 1.0.4 [Linux: amd64]
Compiled at 2019-11-27
Copyright (c) 2006-2019 by Andreas Rumpf

git hash: c8998c498f5e2a0874846eb31309e1d1630faca6
active boot switches: -d:release

[cooldome]

PR welcome
It is actually should be:

ProcDef
  Sym "example"
  Empty
  Empty
  FormalParams
    Empty
    IdentDefs
      Sym "a"    # this a sym too
      Empty
      Sym "thing"  # ← basically, run a semantic check on this
  Empty
  Empty
  DiscardStmt
    TupleConstr
      Sym "a"
      Sym "thing"

The sempass doesn't replace idents with syms while it should. Changes to semProcTypeNode are required.