from . import astnodes
from .scope import Scope, topScope
from ppci import CompilerError

class Semantics:
   """ This class constructs the AST from parser input """
   def __init__(self, diag):
      self.diag = diag
   def addSymbol(self, s):
      if self.curScope.hasSymbol(s.name):
         msg = 'Redefinition of {0}'.format(s.name)
         raise CompilerError(msg, s.loc)
      else:
         self.curScope.addSymbol(s)
   def actOnFuncDef2(self, parameters, returntype, body):
      self.curFunc.body = body
      paramtypes = [p.typ for p in parameters]
      self.curFunc.typ = astnodes.FunctionType(paramtypes, returntype)
      self.curFunc = None
      self.curScope = self.curScope.parent