Constraints.cxx

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#include <assert.h>
#include <stdint.h>
#include <stdlib.h>
#include <dirent.h>
#include <fstream>
#include <iostream>
#include <string>
#include <sstream>

#include <libsherpa/UExcept.hxx>

#include "UocInfo.hxx"
#include "AST.hxx"
#include "Type.hxx"
#include "TypeInfer.hxx"
#include "TypeScheme.hxx"
#include "Typeclass.hxx"
#include "inter-pass.hxx"

using namespace std;
using namespace boost;
using namespace sherpa;

bool
TCConstraints::contains(shared_ptr<Typeclass> tc)
{
  for (iterator itr = begin(); itr != end(); ++itr)
    if ((*itr)->strictlyEquals(tc, false, true))
      return true;

  return false;
}


void
TCConstraints::addPred(shared_ptr<Typeclass> tc)
{
  for (iterator itr = begin(); itr != end(); ++itr) {
    if ((*itr)->strictlyEquals(tc, false, true)) {
      // Compare the two constraints for strict-equality. That is,
      // alpha-renaming is not allowed here. Addition of predcates is
      // not a unifying operation.
      if (tc->flags & TY_CT_SUBSUMED)
        (*itr)->flags |= TY_CT_SUBSUMED;
      return;
    }
  }

  pred.insert(tc);
}

void
TCConstraints::clearPred(shared_ptr<Constraint> ct)
{
  ct =  ct->getType();
  for (iterator itr = begin(); itr != end(); ++itr) {
    shared_ptr<Constraint> pr = (*itr)->getType();
    if (pr == ct) {
      pred.erase(itr);
      return;
    }
  }
}

void
TCConstraints::normalize()
{
  TypeSet allPreds = pred;
  pred.clear();

  for (iterator itr = allPreds.begin(); itr != allPreds.end(); ++itr)
    addPred((*itr));
}

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