TypeMut.hxx

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#ifndef TYPEMUT_HXX
#define TYPEMUT_HXX

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#include <stdlib.h>
#include <dirent.h>
#include <fstream>
#include <iostream>
#include <string>
#include "AST.hxx"
#include "Type.hxx"
 
/* Different options for creating type records. These helper
   functions are in place so that all maybe-records are created at one
   place. Some functions exist so that we can flip copy behaviors in
   some cases easily */

 
/* All type-variables are maybe-types by default, 
   We use bare tvars in some cases (ex: when the sole purpose of
   creating the type variable is unification of the types across all
   legs of a datastructure or expression.*/

static inline boost::shared_ptr<Type> 
newTvar()
{
  return Type::make(ty_tvar);
}

// MBF introduces variability of mutation at the top (outermost) shell
// of a record and also at all fields (recursively) within that record
// up to the ref boundary. This is almost always the one you want.
static inline boost::shared_ptr<Type> 
MBF(boost::shared_ptr<Type> t)
{
  return Type::make(ty_mbFull, newTvar(), t->minMutConstless());
}

// MBT introduces variability of mutation at the top (outermost) shell
// of a record. It says nothing about the mutability of the elements.
static inline boost::shared_ptr<Type> 
MBT(boost::shared_ptr<Type> t)
{
  return Type::make(ty_mbTop, newTvar(), t->getBareType());
}

static inline boost::shared_ptr<Type> 
Mutable(boost::shared_ptr<Type> t)
{
  return Type::make(ty_mutable, t->getBareType());
}

#endif /* TYPEMUT_HXX */

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