def testSearchNoCandidates(self):
# If there are no suitable candidate data vertices for every
# query vertex, then the returned solutions list should be empty.
g = Graph()
g.addEdge(Vertex('v1', 'A'), Vertex('v2', 'B'))
q = Graph()
q.addEdge(Vertex('u1', 'Z'), Vertex('u2', 'Y'))
solutions = g.search(q)
self.assertEquals(len(solutions), 0)
def testApplyProduction_Blackbox2(self):
# Another black-box test of _applyProduction this time with
# numbered vertices.
# Graph is A0->A1,A0->D
g = Graph()
g.addEdge(Vertex('g0', 'A'), Vertex('g1', 'A'))
g.addEdge('g0', Vertex('g2', 'D'))
# Production is A1->A2 ==> A1->A->A2.
# This production adds a new vertex "A" between the existing As,
# leaving the first A still pointing to D.
# Resulting graph: A1->A3->A2; A1->D
lhs = Graph()
lhs.addEdge(Vertex('l0', 'A', 1), Vertex('l1', 'A', 2))
rhs = Graph()
rhs.addEdge(Vertex('r0', 'A', 1), Vertex('r1', 'A'))
rhs.addEdge('r1', Vertex('r2', 'A', 2))
p = Production(lhs, rhs)
gen = Generator()
gen._applyProduction(g, p, {'l0':'g0','l1':'g1'})
# Result has 4 vertices.
self.assertEqual(len(g._vertices), 4)
# <g0,A> is still in the graph.
self.assertIn('g0', g._vertices)
self.assertEqual(g._vertices['g0'].label, 'A')
# <v3,A> has been added.
self.assertIn('v3', g._vertices)
self.assertEqual(g._vertices['v3'].label, 'A')
# g0->v3
self.assertIn(g._vertices['v3'], g._edges['g0'])
# <g1,A> is still in the graph.
self.assertIn('g1', g._vertices)
self.assertEqual(g._vertices['g1'].label, 'A')
# <g2,D> is still in the graph.
self.assertIn('g2', g._vertices)
self.assertEqual(g._vertices['g2'].label, 'D')
# <g0,A>-><g2,D>
self.assertIn(g._vertices['g2'], g._edges['g0'])
# g0->v3
self.assertIn(g._vertices['v3'], g._edges['g0'])
# Output looks fine: A1->A->A, A1->D
self.assertEqual(str(g), 'digraph {\nA_v3->A_g1;\nA_g0->D_g2;\nA_g0->A_v3;\n\n}')
def testFindCandidates(self):
# Create empty data and query graphs.
g = Graph()
q = Graph()
# Searching finds no candidates.
self.assertFalse(g._findCandidates(q))
# Add some data vertices.
g.addEdge(Vertex('u1', 'A'), Vertex('u2', 'B'))
# Empty query graph still finds no candidates.
self.assertFalse(g._findCandidates(q))
# Add some query vertices.
q.addEdge(Vertex('u1', 'A'), Vertex('u2', 'B'))
q.addEdge('u1', Vertex('u3', 'C'))
# Data graph has no 'C', so still returns false.
self.assertFalse(g._findCandidates(q))
# Add a vertex for C, and now the test should succeeed.
g.addEdge('u1', Vertex('u3', 'C'))
u1 = q._vertices['u1']
self.assertTrue(g._findCandidates(q))
self.assertEquals(len(u1.candidates), 1)
def testSearchTwoSolutions(self):
# A1_g0->B_g1->C_g2, A2_g3->B_g1
g = Graph()
g.addEdge(Vertex('g0', 'A'), Vertex('g1', 'B'))
g.addEdge('g1', Vertex('g2', 'C'))
g.addEdge(Vertex('g3', 'A'), 'g1')
#g.addEdge('g3', 'g2')
# A_g0->B_g1->C_g2
q = Graph()
q.addEdge(Vertex('g0', 'A'), Vertex('g1', 'B'))
q.addEdge('g1', Vertex('g2', 'C'))
solutions = g.search(q)
self.assertEquals(len(solutions), 2)
# First A->B,C is found.
self.assertEquals(solutions[0]['g0'], 'g3')
self.assertEquals(solutions[0]['g1'], 'g1')
self.assertEquals(solutions[0]['g2'], 'g2')
# Second A->B,C is found.
self.assertEquals(solutions[1]['g0'], 'g0')
self.assertEquals(solutions[1]['g1'], 'g1')
self.assertEquals(solutions[1]['g2'], 'g2')
def testFindMatchingProductions(self):
# Providing no productions should result in no matches.
gen = Generator()
g = Graph()
self.assertEquals( len(gen._findMatchingProductions(g, [])), 0)
# We have a production, but the LHS can't be found in the graph.
# No solutions.
g = Graph()
g.addEdge(Vertex('g0', 'A'), Vertex('g1', 'B'))
lhs = Graph()
lhs.addEdge(Vertex('g0', 'C'), Vertex('g1', 'D'))
rhs = Graph()
p1 = Production(lhs, rhs)
gen = Generator()
self.assertEquals( len(gen._findMatchingProductions(g, [p1])), 0)
# One matching production, a simple vertex "A".
g = Graph()
g.addEdge(Vertex('g0', 'A'), Vertex('g1', 'B'))
lhs = Graph()
lhs.addVertex(Vertex('g0', 'A', '1'))
rhs = Graph()
p1 = Production(lhs, rhs)
self.assertEquals( len(gen._findMatchingProductions(g, [p1])), 1)
# Two matching productions.
g = Graph()
g.addEdge(Vertex('g0', 'A'), Vertex('g1', 'B'))
lhs = Graph()
lhs.addVertex(Vertex('g0', 'A', '2'))
rhs = Graph()
p1 = Production(lhs, rhs)
p2 = Production(lhs, rhs)
self.assertEquals( len(gen._findMatchingProductions(g, [p1, p2])), 2)
def testApplyProductions(self):
# Start graph already has the minimum number of vertices. Nothing done.
g = Graph()
c = {'min_vertices':0}
gen = Generator()
gen.applyProductions(g, None, c)
self.assertEqual(len(g._vertices), 0)
# No matching productions raises an error.
c = {'min_vertices':1}
self.assertRaises(RuntimeError, gen.applyProductions, g, [], c)
# When we're done, g has more at least min_vertices.
g.addEdge(Vertex('g0', 'A'), Vertex('g1', 'A'))
c = {'min_vertices':10}
# Production is A1->A2 ==> A1->A->A2
lhs = Graph()
lhs.addEdge(Vertex('l0', 'A', 1), Vertex('l1', 'A', 2))
rhs = Graph()
rhs.addEdge(Vertex('r0', 'A', 1), Vertex('r1', 'A'))
rhs.addEdge('r1', Vertex('r2', 'A', 2))
p = Production(lhs, rhs)
gen.applyProductions(g, [p], c)
logging.debug(g)
self.assertEqual(len(g._vertices), 10)
def testFindMatchedNeighbors(self):
q = Graph()
# No data should return an empty list.
mn = q._findMatchedNeighbors(None, None)
self.assertEquals(len(mn), 0)
# No matching neighbors should return an empty list.
q.addEdge(Vertex('u1', 'A'), Vertex('u2', 'B'))
u2 = q._vertices['u2']
mn = q._findMatchedNeighbors(u2, [])
self.assertEquals(len(mn), 0)
# Make a matching neighbor and make sure it is returned.
matches = {'u1': 'v1', 'v1': 'u1'}
mn = q._findMatchedNeighbors(u2, matches)
self.assertEquals(len(mn), 1)
self.assertEquals(mn[0].id, 'u1')
def testNextUnmamtchedVertex(self):
matches = {}
# Build a little graph with three nodes.
q = Graph()
q.addEdge(Vertex('u1'), Vertex('u2'))
q.addEdge('u1', Vertex('u3'))
# Call _nextUnmatchedVertex three times. Each time it returns a
# vertex, add it to matches.
for i in range(3):
v = q._nextUnmatchedVertex(matches)
self.assertTrue(v.id in ['u1', 'u2', 'u3'])
matches[v.id] = 'XYZ'
# Now that all of the vertices are labeled, _nextUnmatchedVertex()
# should return None.
self.assertIsNone(q._nextUnmatchedVertex(matches))
def testSubgraphSearchOneCandidateNotJoinable(self):
# The query vertex has a candidate data vertex, but they aren't
# "joinable" -- no solution.
g = Graph()
g.addVertex(Vertex('v1', 'A'))
g.addVertex(Vertex('v2', 'B'))
v1 = g._vertices['v1']
q = Graph()
q.addEdge(Vertex('u1', 'A'), Vertex('u2', 'B'))
q._vertices['u1'].candidates = [v1]
# u2 and v2 are already matched. There's an edge between u1 and
# u2, but no edge between v1 and v2 so u1 and v1 cannot be matched.
matches = {'u2': 'v2'}
self.assertEqual(len(g._solutions), 0)
g._subgraphSearch(matches, q)
self.assertEqual(len(g._solutions), 0)
def testFilterCandidates(self):
# Filtering an empty graph should return an empty array.
g = Graph()
c = g._filterCandidates(None)
self.assertEquals(len(c), 0)
# Build a little graph with two 'A' labeled vertices.
g.addEdge(Vertex('u1', 'A'), Vertex('u2', 'B'))
g.addEdge('u1', Vertex('u3', 'A'))
# Search the graph for all 'X' vertices (should return an empty array.)
u = Vertex('x', 'X')
c = g._filterCandidates(u)
self.assertTrue(len(c) == 0)
# Search for 'A' vertices. Should return two of them.
u = Vertex('x', 'A')
c = g._filterCandidates(u)
self.assertTrue(len(c) == 2)
self.assertTrue(c[0].label == 'A')
self.assertTrue(c[1].label == 'A')
def testApplyProduction(self):
# A basic test that tests all four cases: add and remove vertex,
# and add and remove edge.
# Graph starts with A->B
g = Graph()
g.addEdge(Vertex('g0', 'A'), Vertex('g1', 'B'))
g1 = g._vertices['g1']
# Production lhs matches A->B
lhs = Graph()
lhs.addEdge(Vertex('l0', 'A', 1), Vertex('l1', 'B', 1))
# Production rhs transforms that to A->C
rhs = Graph()
rhs.addEdge(Vertex('r0', 'A', 1), Vertex('r1', 'C'))
p = Production(lhs,rhs)
gen = Generator()
gen._applyProduction(g, p, {'l0':'g0','l1':'g1'})
# g has a new vertex, <v2,C>.
self.assertEqual(len(g._vertices), 2)
self.assertEqual(g._vertices['v1'].label, 'C')
# <g0,A> points to <v2,C>
self.assertEqual(len(g._edges['g0']), 1)
self.assertEqual(g._edges['g0'][0].id, 'v1')
self.assertEqual(g._vertices['v1'].label, 'C')
# <g0,A> no longer points to <g1,B>
self.assertNotIn(g1, g._edges['g0'])
# Vertex <g1,B> has been deleted.
self.assertNotIn('g1', g._vertices)
def testSearchOneSimpleSolution(self):
g = Graph()
g.addEdge(Vertex('v1', 'A'), Vertex('v2', 'B'))
g.addEdge('v1', Vertex('v3', 'C'))
# Query graph is exact replica.
q = Graph()
q.addEdge(Vertex('u1', 'A'), Vertex('u2', 'B'))
q.addEdge('u1', Vertex('u3', 'C'))
solutions = g.search(q)
self.assertEquals(len(solutions), 1)
self.assertEquals(solutions[0]['u1'], 'v1')
self.assertEquals(solutions[0]['u2'], 'v2')
self.assertEquals(solutions[0]['u3'], 'v3')
def testApplyProduction_Blackbox(self):
# Black-box test of _applyProduction.
# Graph is A->C,D
g = Graph()
g.addEdge(Vertex('g0', 'A'), Vertex('g1', 'C'))
g.addVertex(Vertex('g2', 'D'))
# Production is A->C,D ==> A->B,C.
# This adds vertex B, adds edge from A->B, deletes edge from A->C,
# and deletes vertex D.
lhs = Graph()
lhs.addEdge(Vertex('l0', 'A'), Vertex('l1', 'C'))
lhs.addVertex(Vertex('l2', 'D'))
rhs = Graph()
rhs.addEdge(Vertex('r0', 'A'), Vertex('r1', 'B'))
rhs.addVertex(Vertex('r2', 'C'))
p = Production(lhs, rhs)
gen = Generator()
gen._applyProduction(g, p, {'l0':'g0','l1':'g1','l2':'g2'})
self.assertEqual(len(g._vertices), 3)
# <g0,A> is still in the graph.
self.assertIn('g0', g._vertices)
self.assertEqual(g._vertices['g0'].label, 'A')
# <v3,B> has been added.
self.assertIn('v2', g._vertices)
self.assertEqual(g._vertices['v2'].label, 'B')
# A->B
self.assertIn(g._vertices['v2'], g._edges['g0'])
# <g1,C> is still in the graph.
self.assertIn('g1', g._vertices)
self.assertEqual(g._vertices['g1'].label, 'C')
# A->C has been removed.
self.assertNotIn(g._vertices['g1'], g._edges['g0'])
# <g2,D> has been removed.
self.assertNotIn('g2', g._vertices)
# Output looks fine.
self.assertEqual(str(g), 'digraph {\nA_g0->B_v2;\n\n}')
def testAddNewEdges(self):
# rhs has no edges, so nothing changes.
g = Graph()
lhs = Graph()
rhs = Graph()
p = Production(lhs,rhs)
rhsMapping = {}
gen = Generator()
self.assertEqual(len(g._edges), 0)
gen._addNewEdges(g, p, rhsMapping)
self.assertEqual(len(g._edges), 0)
# rhs has an edge, but it already exists in the graph.
g = Graph()
g.addEdge(Vertex('g0', 'A'), Vertex('g1', 'B'))
lhs = Graph()
rhs = Graph()
rhs.addEdge(Vertex('r0', 'A', 1), Vertex('r1', 'B', 1))
p = Production(lhs,rhs)
rhsMapping = {'r0':'g0', 'r1':'g1'}
gen = Generator()
self.assertEqual(len(g._edges['g0']), 1)
gen._addNewEdges(g, p, rhsMapping)
self.assertEqual(len(g._edges['g0']), 1)
# rhs has a new edge not in graph.
g = Graph()
g.addVertex(Vertex('g0', 'A'))
g.addVertex(Vertex('g1', 'B'))
lhs = Graph()
rhs = Graph()
rhs.addEdge(Vertex('r0', 'A', 1), Vertex('r1', 'B', 1))
p = Production(lhs,rhs)
rhsMapping = {'r0':'g0', 'r1':'g1'}
gen = Generator()
self.assertEqual(len(g._edges['g0']), 0)
gen._addNewEdges(g, p, rhsMapping)
self.assertEqual(len(g._edges['g0']), 1)
self.assertEqual(g._edges['g0'][0].id, 'g1')
class TestGraphClass(unittest.TestCase):
def setUp(self):
self.g = Graph()
def testConstructor(self):
# New graphs should be empty.
self.assertTrue(len(self.g._vertices) == 0)
self.assertTrue(len(self.g._edges) == 0)
self.assertTrue(len(self.g._neighbors) == 0)
def testAddVertex(self):
# Correct add.
v = self.g.addVertex(Vertex('u1'))
self.assertTrue('u1' in self.g._vertices)
# Adding an existing vertex should return the existing vertex.
self.assertEquals(self.g.addVertex(v), v)
def testAddEdge(self):
# Add edge with two vid's
a = self.g.addVertex(Vertex('u1', 'A'))
b = self.g.addVertex(Vertex('u2', 'B'))
self.g.addEdge('u1', 'u2')
# Add edge with one vid and one Vertex.
self.g.addEdge('u1', Vertex('u3', 'C'))
c = self.g._vertices['u3']
# Add edge with one Vertex and one vid.
self.g.addEdge(Vertex('u4', 'D'), 'u1')
d = self.g._vertices['u4']
# Add edge with two Vertics.
self.g.addEdge(Vertex('u5', 'E'), Vertex('u6', 'F'))
e = self.g._vertices['u5']
f = self.g._vertices['u6']
# Make sure A points to B and C.
self.assertTrue(b in self.g._edges['u1'])
self.assertTrue(c in self.g._edges['u1'])
self.assertTrue(a in self.g._edges['u4'])
self.assertTrue(f in self.g._edges['u5'])
# Make sure neighbors all reference each other.
self.assertTrue(b in self.g._neighbors['u1'])
self.assertTrue(c in self.g._neighbors['u1'])
self.assertTrue(d in self.g._neighbors['u1'])
self.assertTrue(a in self.g._neighbors['u2'])
self.assertTrue(a in self.g._neighbors['u3'])
self.assertTrue(a in self.g._neighbors['u4'])
self.assertTrue(e in self.g._neighbors['u6'])
self.assertTrue(f in self.g._neighbors['u5'])
# Make sure the vertex degrees were updated.
self.assertEquals(self.g._vertices['u1'].degree, 3)
self.assertEquals(self.g._vertices['u2'].degree, 1)
self.assertEquals(self.g._vertices['u3'].degree, 1)
self.assertEquals(self.g._vertices['u4'].degree, 1)
self.assertEquals(self.g._vertices['u5'].degree, 1)
self.assertEquals(self.g._vertices['u6'].degree, 1)
def testDeleteEdge(self):
# Referencing non-existing vertices should return False
self.assertFalse(self.g.deleteEdge('aaa', 'bbb'))
# Build A->B
self.g.addEdge(Vertex('u1', 'A'), Vertex('u2', 'B'))
u1 = self.g._vertices['u1']
u2 = self.g._vertices['u2']
# Deleting a non-existant edge should return False.
self.assertFalse(self.g.deleteEdge('u1', 'bbb'))
# Deleting an existing edge should return True.
self.assertTrue(self.g.deleteEdge('u1', 'u2'))
# u2 should not appear in the list of edges from u1.
self.assertTrue(u2 not in self.g._edges['u1'])
# u2 should not appear in the list of neighbors of u1.
self.assertTrue(u2 not in self.g._neighbors['u1'])
# Both vertex degress should be decremented.
self.assertEquals(u1.degree, 0)
self.assertEquals(u2.degree, 0)
def testDeleteVertex(self):
# Deleting a non-existing vertex raises an exception.
self.assertIsNone(self.g.deleteVertex('X'))
# Build A->B, B->A
self.g.addEdge(Vertex('u1', 'A'), Vertex('u2', 'B'))
self.g.addEdge('u2', 'u1')
u1 = self.g._vertices['u1']
u2 = self.g._vertices['u2']
self.g.deleteVertex('u1')
# u1 shouldn't appear anywhere as an edge or neighbor.
self.assertTrue('u1' not in self.g._edges)
self.assertTrue('u1' not in self.g._neighbors)
self.assertTrue('u1' not in self.g._edges['u2'])
self.assertTrue('u1' not in self.g._neighbors['u2'])
# u1 isn't a vertex anymore.
self.assertTrue('u1' not in self.g._vertices)
def testEdgesProperty(self):
# Build A->B, B->C
self.g.addEdge(Vertex('u1', 'A'), Vertex('u2', 'B'))
self.g.addEdge('u2', Vertex('u3', 'C'))
for e in self.g.edges:
if e[0].id == 'u1':
self.assertEquals(e[1].id, 'u2')
elif e[0].id == 'u2':
self.assertEquals(e[1].id, 'u3')
else:
self.assertFalse(True)
def testFindVertex(self):
u1 = self.g.addVertex(Vertex('u1', 'A', 1))
self.assertIsNone(self.g.findVertex('X'))
self.assertIsNone(self.g.findVertex('A2'))
self.assertEqual(self.g.findVertex('A1'), u1)
def testHasEdgeBetweenVertices(self):
self.g.addEdge(Vertex('u0', 'A'), Vertex('u1', 'B'))
self.g.addEdge('u1', Vertex('u2', 'C'))
self.assertTrue(self.g.hasEdgeBetweenVertices('u0', 'u1'))
self.assertFalse(self.g.hasEdgeBetweenVertices('u0', 'u2'))
self.assertFalse(self.g.hasEdgeBetweenVertices('XX', 'XX'))
self.assertFalse(self.g.hasEdgeBetweenVertices('u0', 'XX'))
def testLabelsProperty(self):
self.g.addVertex(Vertex('u1', 'A'))
self.g.addVertex(Vertex('u2', 'B'))
self.g.addVertex(Vertex('u3', 'C'))
labels = self.g.labels
self.assertEquals(len(labels), 3)
self.assertTrue('A' in labels)
self.assertTrue('B' in labels)
self.assertTrue('C' in labels)
def testNamesProperty(self):
self.g.addVertex(Vertex('u1', 'A', 1))
self.g.addVertex(Vertex('u2', 'B', 2))
self.g.addVertex(Vertex('u3', 'C', 3))
names = self.g.names
self.assertEquals(len(names), 3)
self.assertTrue('A1' in names)
self.assertTrue('B2' in names)
self.assertTrue('C3' in names)
def testNumVertices(self):
# Empty graph.
self.assertEquals(self.g.numVertices, 0)
# One vertex.
a = self.g.addVertex(Vertex('u1'))
self.assertEquals(self.g.numVertices, 1)
def testRepr(self):
# Test of the output function (__repr__).
# No vertices.
self.assertEquals(self.g.__repr__(), "digraph {\n\n}")
# A
self.g.addVertex(Vertex('u1', 'A'))
self.assertEquals(self.g.__repr__(), "digraph {\nA_u1\n}")
# A->B
self.g.addEdge('u1', Vertex('u2', 'B'))
self.assertEquals(self.g.__repr__(), "digraph {\nA_u1->B_u2;\n\n}")
# A->B->C
self.g.addEdge('u2', Vertex('u3', 'C'))
self.assertEquals(self.g.__repr__(),
"digraph {\nA_u1->B_u2;\nB_u2->C_u3;\n\n}")
# A->B->C, A->D
self.g.addEdge('u1', Vertex('u4', 'D'))
self.assertEquals(
self.g.__repr__(),
"digraph {\nA_u1->B_u2;\nA_u1->D_u4;\nB_u2->C_u3;\n\n}")
def testIsJoinable(self):
# If there are no matched vertices yet (we just started the matching
# process), then should return True.
g = Graph()
self.assertTrue(g._isJoinable(None, None, None, {}))
# If there are matches, but none adjacent to u, then should
# return False.
g = Graph()
g.addEdge(Vertex('v1'), Vertex('v2'))
v = g._vertices['v1']
q = Graph()
q.addEdge(Vertex('u1'), Vertex('u2'))
u = q._vertices['u1']
self.assertFalse(g._isJoinable(u, v, q, {'u3': 'v3', 'v3': 'u3'}))
# If an edge exists between u and n, but the other direction between
# v and m, should return False
g = Graph()
g.addEdge(Vertex('v1'), Vertex('v2'))
v = g._vertices['v1']
q = Graph()
q.addEdge(Vertex('u2'), Vertex('u1'))
u = q._vertices['u1']
self.assertFalse(g._isJoinable(u, v, q, {'u2': 'v2', 'v2': 'u2'}))
# If an edge exists between n and u, but the other direction between
# m and v, should return False
g = Graph()
g.addEdge(Vertex('v2'), Vertex('v1'))
v = g._vertices['v1']
q = Graph()
q.addEdge(Vertex('u1'), Vertex('u2'))
u = q._vertices['u1']
self.assertFalse(g._isJoinable(u, v, q, {'u2': 'v2', 'v2': 'u2'}))
# Correct case 1. Edge between u and n, and between v and m.
g = Graph()
g.addEdge(Vertex('v1'), Vertex('v2'))
v = g._vertices['v1']
q = Graph()
q.addEdge(Vertex('u1'), Vertex('u2'))
u = q._vertices['u1']
self.assertTrue(g._isJoinable(u, v, q, {'u2': 'v2', 'v2': 'u2'}))
# Correct case 2. Edge between n and u, and between m and v.
g = Graph()
g.addEdge(Vertex('v2'), Vertex('v1'))
v = g._vertices['v1']
q = Graph()
q.addEdge(Vertex('u2'), Vertex('u1'))
u = q._vertices['u1']
self.assertTrue(g._isJoinable(u, v, q, {'u2': 'v2', 'v2': 'u2'}))
def testDeleteMissingEdges(self):
# If lhs has no edges, then there's nothing missing from the rhs.
# Nothing is done to the graph.
g = Graph()
g.addEdge(Vertex('g0', 'A', 1), Vertex('g1', 'B', 1))
lhs = Graph()
rhs = Graph()
p = Production(lhs,rhs)
lhsMapping = {}
rhsMapping = {}
gen = Generator()
self.assertEqual(len(g._edges['g0']), 1)
gen._deleteMissingEdges(g, p, lhsMapping, rhsMapping)
self.assertEqual(len(g._edges['g0']), 1)
# lhs has an edge, but it also appears on the rhs. Nothing done.
g = Graph()
g.addEdge(Vertex('g0', 'A', 1), Vertex('g1', 'B', 1))
lhs = Graph()
lhs.addEdge(Vertex('l0', 'A', 1), Vertex('l1', 'B', 1))
rhs = Graph()
rhs.addEdge(Vertex('r0', 'A', 1), Vertex('r1', 'B', 1))
p = Production(lhs,rhs)
lhsMapping = {'l0':'g0', 'l1':'g1'}
rhsMapping = {'r0':'g0', 'r1':'g1'}
gen = Generator()
self.assertEqual(len(g._edges['g0']), 1)
gen._deleteMissingEdges(g, p, lhsMapping, rhsMapping)
self.assertEqual(len(g._edges['g0']), 1)
# lhs has an edge, but the starting vertex doesn't appear in the RHS.
# The edge should be deleted from the graph.
g = Graph()
g.addEdge(Vertex('g0', 'A', 1), Vertex('g1', 'B', 1))
lhs = Graph()
lhs.addEdge(Vertex('l0', 'A', 1), Vertex('l1', 'B', 1))
rhs = Graph()
rhs.addVertex(Vertex('r0', 'A', 2))
rhs.addVertex(Vertex('r1', 'B', 1))
p = Production(lhs,rhs)
lhsMapping = {'l0':'g0', 'l1':'g1'}
rhsMapping = {'r1':'g1'}
gen = Generator()
self.assertEqual(len(g._edges['g0']), 1)
gen._deleteMissingEdges(g, p, lhsMapping, rhsMapping)
self.assertEqual(len(g._edges['g0']), 0)
# lhs has an edge, but the ending vertex doesn't appear in the RHS.
# The edge should be deleted from the graph.
g = Graph()
g.addEdge(Vertex('g0', 'A', 1), Vertex('g1', 'B', 1))
lhs = Graph()
lhs.addEdge(Vertex('l0', 'A', 1), Vertex('l1', 'B', 1))
rhs = Graph()
rhs.addVertex(Vertex('r0', 'A', 1))
rhs.addVertex(Vertex('r1', 'B', 2))
p = Production(lhs,rhs)
lhsMapping = {'l0':'g0', 'l1':'g1'}
rhsMapping = {'r0':'g0'}
gen = Generator()
self.assertEqual(len(g._edges['g0']), 1)
gen._deleteMissingEdges(g, p, lhsMapping, rhsMapping)
self.assertEqual(len(g._edges['g0']), 0)
# lhs has an edge, but it's gone from the rhs. It should be deleted
# from the graph.
g = Graph()
g.addEdge(Vertex('g0', 'A', 1), Vertex('g1', 'B', 1))
lhs = Graph()
lhs.addEdge(Vertex('l0', 'A', 1), Vertex('l1', 'B', 1))
rhs = Graph()
rhs.addVertex(Vertex('r0', 'A', 1))
rhs.addVertex(Vertex('r1', 'B', 1))
p = Production(lhs,rhs)
lhsMapping = {'l0':'g0', 'l1':'g1'}
rhsMapping = {'r0':'g0', 'r1':'g1'}
gen = Generator()
self.assertEqual(len(g._edges['g0']), 1)
gen._deleteMissingEdges(g, p, lhsMapping, rhsMapping)
self.assertEqual(len(g._edges['g0']), 0)