PrimitiveTest.java

package com.igormaznitsa.prol.test;

import com.igormaznitsa.prol.data.Term;
import com.igormaznitsa.prol.io.DefaultProlStreamManagerImpl;
import com.igormaznitsa.prol.logic.Goal;
import com.igormaznitsa.prol.logic.ProlContext;
import com.igormaznitsa.prol.parser.ProlConsult;
import junit.framework.TestCase;
import org.junit.Test;

public class PrimitiveTest extends TestCase {

  @Test
  public void testAccList() throws Exception {
    final ProlContext context = makeContext("list(X):-X=A,A=B,B=C,C=D,D=E,A=[_,_,_,_],B=[a,_,_,_],C=[_,b,_,_],D=[_,_,c,_],E=[_,_,_,e].");
    final Goal goal = new Goal("list(F).", context);

    assertNotNull(goal.solve());
    assertEquals(goal.getVarAsText("F"), "['a','b','c','e']");
    assertNull(goal.solve());
  }

  @Test
  public void testPermutation() throws Exception {
    final ProlContext context = makeContext("del(X,[X|Tail],Tail).del(X,[Y|Tail],[Y|Tail1]):-del(X,Tail,Tail1).insert(X,List,BiggerList):-del(X,BiggerList,List).permutation([],[]).permutation([X|L],P):-permutation(L,L1),insert(X,L1,P).");
    final Goal goal = new Goal("permutation([red,blue,green],X).", context);

    final String[] etalon = new String[]{
      "['red','blue','green']",
      "['blue','red','green']",
      "['blue','green','red']",
      "['red','green','blue']",
      "['green','red','blue']",
      "['green','blue','red']"
    };

    for (int li = 0; li < etalon.length; li++) {
      assertNotNull(goal.solve());
      assertEquals(goal.getVarAsText("X"), etalon[li]);
    }
    assertNull(goal.solve());
  }

  @Test
  public void testVarLoop() throws Exception {
    final ProlContext context = makeContext("a(a1).a(X):-X=100. a(2).");
    final Goal goal = new Goal("X=Y,Y=X,Y=2.", context);

    assertNotNull(goal.solve());
    assertEquals(goal.getVarAsText("Y"), "2");
    assertNull(goal.solve());
  }

  @Test
  public void testClause() throws Exception {
    final ProlContext context = makeContext("a(a1).a(X):-X=100. a(2).");
    final Goal goal = new Goal("clause(a(X),Y).", context);

    assertNotNull(goal.solve());
    assertEquals(goal.getVarAsText("X"), "'a1'");
    assertEquals(goal.getVarAsText("Y"), "'true'");

    assertNotNull(goal.solve());
    assertNull(goal.getVarAsText("X"));
    assertEquals(goal.getVarAsText("Y"), "X = 100");

    assertNotNull(goal.solve());
    assertEquals(goal.getVarAsText("X"), "2");
    assertEquals(goal.getVarAsText("Y"), "'true'");

    assertNull(goal.solve());

  }

  @Test
  public void testThrowCatch() throws Exception {
    final ProlContext context = makeContext("a(X):-X=999;throw(some_exception).");
    final Goal goal = new Goal("catch(a(X),Err,Y='exc').", context);

    assertNotNull(goal.solve());
    assertEquals(goal.getVarAsText("X"), "999");
    assertNull(goal.getVarAsText("Err"));
    assertNull(goal.getVarAsText("Y"));

    assertNotNull(goal.solve());
    assertNull(goal.getVarAsText("X"));
    assertEquals(goal.getVarAsText("Err"), "some_exception");
    assertEquals(goal.getVarAsText("Y"), "'exc'");

    assertNull(goal.solve());
  }

  @Test
  public void testIfThen() throws Exception {
    final ProlContext context = makeContext("b(b1).b(b2).a(a1).a(a2).");

    final Goal goal = new Goal("b(B)->a(A);b(C).", context);

    final String[] results = new String[]{"'a1'", "'a2'", "'a3'", "'a4'"};

    assertNotNull(goal.solve());
    assertEquals(goal.getVarAsText("B"), "'b1'");
    assertEquals(goal.getVarAsText("A"), "'a1'");
    assertNull(goal.getVarAsText("C"));

    assertNotNull(goal.solve());
    assertEquals(goal.getVarAsText("B"), "'b1'");
    assertEquals(goal.getVarAsText("A"), "'a2'");
    assertNull(goal.getVarAsText("C"));

    assertNull(goal.solve());
  }

  @Test
  public void testTrue() throws Exception {
    final ProlContext context = makeContext("a(a1).a(a2).a(a3).a(a4).");

    final Goal goal = new Goal("(true,true;fail),a(X).", context);

    final String[] results = new String[]{"a1", "a2", "a3", "a4"};

    int index = 0;

    while (true) {
      Term result = goal.solve();
      if (result == null) {
        break;
      }
      assertEquals(goal.getVarForName("X").getValue().getText(), results[index++]);
    }

    assertEquals(index, results.length);

  }

  @Test
  public void testOr1() throws Exception {
    final ProlContext context = makeContext("a([]).");

    final Goal goal = new Goal("X=a;X=b;X=c;X=d.", context);

    final String[] results = new String[]{"'a'", "'b'", "'c'", "'d'"};

    for (int li = 0; li < results.length; li++) {
      assertNotNull(goal.solve());
      assertEquals(goal.getVarAsText("X"), results[li]);
    }

    assertNull(goal.solve());
  }

  @Test
  public void testOr2() throws Exception {
    final ProlContext context = makeContext("testor(X,Y):-X='a1',write('x'),Y='b1',write('y');X='a2',write('x'),Y='b2',write('y');X='a3',write('x'),Y='b3',write('y');X='a4',write('x'),Y='b4',write('y');X='a5',write('x'),Y='b5',write('y').");

    final Goal goal = new Goal("testor(X,Y).", context);

    final String[] results = new String[]{"a1", "b1", "a2", "b2", "a3", "b3", "a4", "b4", "a5", "b5"};

    int index = 0;
    while (true) {
      final Term term = goal.solve();
      if (term == null) {
        break;
      }
      assertEquals(results[index++], goal.getVarForName("X").getValue().getText());
      assertEquals(results[index++], goal.getVarForName("Y").getValue().getText());
    }

    assertEquals(index, results.length);
  }

  @Test
  public void testAnonimousVar() throws Exception {
    final ProlContext context = makeContext("a(a1,b1).a(a2,b2).a(a3,b3).a(a4,b4).");

    final Goal goal = new Goal("a(X,_).", context);

    final String[] results = new String[]{"'a1'", "'a2'", "'a3'", "'a4'"};

    int index = 0;
    for (int li = 0; li < results.length; li++) {
      assertNotNull(goal.solve());
      assertEquals(goal.getVarAsText("X"), results[index++]);
    }
    assertNull(goal.solve());
  }

  @Test
  public void testAtom() throws Exception {
    final ProlContext context = makeContext("a(a1).a(a2).a(a3).a(a4).");

    final Goal goal = new Goal("a(X).", context);

    final String[] results = new String[]{"'a1'", "'a2'", "'a3'", "'a4'"};

    for (int li = 0; li < results.length; li++) {
      assertNotNull(goal.solve());
      assertEquals(goal.getVarAsText("X"), results[li]);
    }
    assertNull(goal.solve());

    final Goal goal2 = new Goal("aa(X).", context);
    assertNull(goal2.solve());
  }

  @Test
  public void testAtom2() throws Exception {
    final ProlContext context = makeContext("a(a1,b1).a(a2,b2).a(a3,b3).");

    final Goal goal = new Goal("a(a3,X).", context);

    assertNotNull(goal.solve());
    assertEquals("'b3'", goal.getVarAsText("X"));
    assertNull(goal.solve());
  }

  @Test
  public void testSingleRule() throws Exception {
    final ProlContext context = makeContext("a(a1).a(a2).a(a3).a(a4).");

    final Goal goal = new Goal("b(X):-a(X).", context);

    final String[] results = new String[]{"'a1'", "'a2'", "'a3'", "'a4'"};

    for (int li = 0; li < results.length; li++) {
      assertNotNull(goal.solve());
      assertEquals(goal.getVarAsText("X"), results[li]);
    }
    assertNull(goal.solve());
  }

  @Test
  public void testSingleInsideRule() throws Exception {
    final ProlContext context = makeContext("a(a1).a(a2).a(a3).a(a4).b(X):-a(X).");

    final Goal goal = new Goal("b(X).", context);

    final String[] results = new String[]{"'a1'", "'a2'", "'a3'", "'a4'"};

    for (int li = 0; li < results.length; li++) {
      assertNotNull(goal.solve());
      assertEquals(goal.getVarAsText("X"), results[li]);
    }
    assertNull(goal.solve());
  }

  @Test
  public void testSingleInsideRule2() throws Exception {
    final ProlContext context = makeContext("c(c1).c(c2).a(X):-c(X).a(a2).a(a3).a(a4).b(X):-a(X).");

    final Goal goal = new Goal("b(X).", context);

    final String[] results = new String[]{"'c1'", "'c2'", "'a2'", "'a3'", "'a4'"};

    for (int li = 0; li < results.length; li++) {
      assertNotNull(goal.solve());
      assertEquals(goal.getVarAsText("X"), results[li]);
    }
    assertNull(goal.solve());
  }

  @Test
  public void testANDGoal() throws Exception {
    final ProlContext context = makeContext("a(a1).a(a2).b(b1).b(b2).");

    final Goal goal = new Goal("a(A),b(B).", context);

    final String[] resultsA = new String[]{"'a1'", "'a2'"};
    final String[] resultsB = new String[]{"'b1'", "'b2'"};

    for (int la = 0; la < 2; la++) {
      for (int lb = 0; lb < 2; lb++) {
        assertNotNull(goal.solve());
        assertEquals(goal.getVarAsText("A"), resultsA[la]);
        assertEquals(goal.getVarAsText("B"), resultsB[lb]);
      }
    }

    assertNull(goal.solve());
  }

  @Test
  public void testORGoal() throws Exception {
    final ProlContext context = makeContext("a(a1).a(a2).b(b1).b(b2).");

    final Goal goal = new Goal("a(A);b(A).", context);
    final String[] results = new String[]{"'a1'", "'a2'", "'b1'", "'b2'"};

    for (int la = 0; la < results.length; la++) {
      assertNotNull(goal.solve());
      assertEquals(goal.getVarAsText("A"), results[la]);
    }
    assertNull(goal.solve());
  }

  @Test
  public void testCutAnd() throws Exception {
    final ProlContext context = makeContext("a(a1).a(a2).b(b1).b(b2).");

    final Goal goal = new Goal("a(A),!,b(B).", context);

    final String[] resultsA = new String[]{"'a1'"};
    final String[] resultsB = new String[]{"'b1'", "'b2'"};

    for (int la = 0; la < resultsA.length; la++) {
      for (int lb = 0; lb < resultsB.length; lb++) {
        assertNotNull(goal.solve());
        assertEquals(goal.getVarAsText("A"), resultsA[la]);
        assertEquals(goal.getVarAsText("B"), resultsB[lb]);
      }
    }

    assertNull(goal.solve());
  }

  @Test
  public void testCut1() throws Exception {
    final ProlContext context = makeContext("a(a1):-!.a(a2).a(a3).a(a4).");

    final Goal goal = new Goal("a(X).", context);
    assertNotNull(goal.solve());
    assertEquals(goal.getVarAsText("X"), "'a1'");
    assertNull(goal.solve());
  }

  @Test
  public void testCut2() throws Exception {
    final ProlContext context = makeContext("c(c1).c(c2).a(X):-c(X).a(a2):-!.a(a3).a(a4).b(X):-a(X).");

    final Goal goal = new Goal("b(X).", context);

    final String[] results = new String[]{"'c1'", "'c2'", "'a2'"};

    for (int li = 0; li < results.length; li++) {
      assertNotNull(goal.solve());
      assertEquals(goal.getVarAsText("X"), results[li]);
    }
    assertNull(goal.solve());
  }

  @Test
  public void testCut3() throws Exception {
    final ProlContext context = makeContext("c(c1).c(c2).a(X):-!,c(X).a(a2).a(a3).a(a4).b(X):-a(X).");

    final Goal goal = new Goal("b(X).", context);

    final String[] results = new String[]{"'c1'", "'c2'"};

    for (int li = 0; li < results.length; li++) {
      assertNotNull(goal.solve());
      assertEquals(goal.getVarAsText("X"), results[li]);
    }
    assertNull(goal.solve());
  }

  @Test
  public void testCut4() throws Exception {
    final ProlContext context = makeContext("f(f1).f(f2).c(c1).c(c2).c(c3).a(X):-c(X);!,f(X).a(a2).a(a3).a(a4).b(X):-a(X).");

    final Goal goal = new Goal("b(X).", context);

    final String[] results = new String[]{"'c1'", "'c2'", "'c3'", "'f1'", "'f2'"};

    for (int li = 0; li < results.length; li++) {
      assertNotNull(goal.solve());
      assertEquals(goal.getVarAsText("X"), results[li]);
    }
    assertNull(goal.solve());
  }

  @Test
  public void testLocalCut() throws Exception {
    final ProlContext context = makeContext("f(f1).f(f2).c(c1).c(c2).c(c3).a(X):-c(X),!!.a(a2).a(a3).a(a4).b(X):-a(X).");

    final Goal goal = new Goal("b(X).", context);
    final String[] results = new String[]{"'c1'", "'a2'", "'a3'", "'a4'"};

    for (int li = 0; li < results.length; li++) {
      assertNotNull(goal.solve());
      assertEquals(goal.getVarAsText("X"), results[li]);
    }
    assertNull(goal.solve());

  }

  private ProlContext makeContext(final String knowledgeBase) throws Exception {
    final ProlContext context = new ProlContext("PreparedGoal test", DefaultProlStreamManagerImpl.getInstance());
    final ProlConsult consult = new ProlConsult(knowledgeBase, context);
    consult.consult();
    return context;
  }
}