compile time code execution problem

[jzakiya]

I want to execute the code below at compile time to initialize the global 
variables shown - modpg, rescnt, residues, ep.
    
    
    proc genPGparameters(prime: int): tuple =
      echo("generating parameters for P", prime)
      let primes = [2, 3, 5, 7, 11, 13, 17, 19, 23]
      var modpg = 1
      var excluded_primes = 0
      for prm in primes:
        excluded_primes += 1; modpg *= prm; if prm == prime: break
      
      var pc = 3; var residues = @[1]
      while pc < modpg:
        if gcd(modpg, pc) == 1: residues.add(pc)
        pc += 2
      residues.add(modpg + 1)
      let rescnt = residues.len-1
      result = (modpg, rescnt, residues, excluded_primes)
    
    const (modpg, rescnt, residues, ep) = genPGparameters(11)
    
    

I get this following error message pointer about the last line.
    
    
    ssozp11x1c3parnew.nim(58, 7) Error: identifier expected, but found '(
    
    

I can't find the docs for this case, but I guess it's something simple. How do 
I get the code to work?