from . import astnodes

class Scope:
   """ A scope contains all symbols in a scope """
   def __init__(self, parent=None):
      self.symbols = {}
      self.parent = parent
   def __iter__(self):
      # Iterate in a deterministic manner:
      return iter(self.Constants + self.Variables + self.Functions)
   @property
   def Syms(self):
      syms = self.symbols.values()
      return sorted(syms, key=lambda v: v.name)
   @property
   def Constants(self):
      return [s for s in self.Syms if type(s) is astnodes.Constant]
   @property
   def Variables(self):
      return [s for s in self.Syms if type(s) is astnodes.Variable]
   @property
   def Functions(self):
      return [s for s in self.Syms if type(s) is astnodes.Function]
   def getSymbol(self, name):
      if name in self.symbols:
         return self.symbols[name]
      # Look for symbol:
      if self.parent:
         return self.parent.getSymbol(name)
      raise CompilerException("Symbol {0} not found".format(name), name.loc)
   def hasSymbol(self, name):
      if name in self.symbols:
         return True
      if self.parent:
         return self.parent.hasSymbol(name)
      return False
   def addSymbol(self, sym):
      self.symbols[sym.name] = sym

# buildin types:
intType = astnodes.BaseType('int')
doubleType = astnodes.BaseType('double')
voidType = astnodes.BaseType('void')
boolType = astnodes.BaseType('bool')
stringType = astnodes.BaseType('string')
byteType = astnodes.BaseType('byte')

def createBuiltins(scope):
   for tn in ['u64', 'u32', 'u16', 'u8']:
      scope.addSymbol(astnodes.BaseType(tn))
   for t in [intType, doubleType, voidType, boolType, stringType, byteType]:
      scope.addSymbol(t)

topScope = Scope()
createBuiltins(topScope)