#!/usr/bin/env python
"""
exclaim.py - Pluvo Standard Library: exclaim
Author: Joe Geldart, durham.ac.uk
Author: Sean B. Palmer, inamidst.com
Cf. http://paste.lisp.org/display/21936

Note, Joe wants to use "!" for this function; how does this interact with !
being not? Is there a context in which the use of ! can be determined? Possibly
arg length for example?

Better would likely be to merge this in with method. See for example: 
http://paste.lisp.org/display/21937#1
"""

try: 
   from basics import method
   from datatypes import Table, Symbol
except ImportError: 
   from pluvo.basics import method
   from pluvo.datatypes import Table, Symbol

def exclaim(env, *args):
   """@exclaim param1: var1 param2: var2 block"""

   if len(args) < 3: 
      raise ValueError("Action must have at least one symbol and a block")
   
   # If we only have one symbol, we're a predicate without parameter
   if len(args) == 3:
      predsym, question, block = args
      method(env, predsym, Symbol("="), Table(), block)      
   else: 
      symname = ""
      argspec = Table()
      args, block = args[:-1], args[-1]

      while args: 
         (arg, colon, var), args = args[:3], args[3:]
         # print arg, colon, var
         symname += arg.name
         argspec.append(var)

      actsym = Symbol(symname)
      method(env, actsym, Symbol("="), argspec, block)

main = exclaim

if __name__ == '__main__': 
   print __doc__