Add task 8

project/task8.py

@@ -0,0 +1,97 @@
+import networkx as nx
+import numpy as np
+import pyformlang
+import pyformlang.cfg
+from pyformlang.finite_automaton import (
+    NondeterministicFiniteAutomaton,
+)
+import pyformlang.rsa
+from scipy.sparse import csr_matrix
+
+from project.task2 import graph_to_nfa
+from project.task3 import AdjacencyMatrixFA, intersect_automata
+
+
+def tensor_based_cfpq(
+    rsa: pyformlang.rsa.RecursiveAutomaton,
+    graph: nx.DiGraph,
+    start_nodes: set[int] = None,
+    final_nodes: set[int] = None,
+) -> set[tuple[int, int]]:
+    nfa_of_rsm = NondeterministicFiniteAutomaton()
+
+    def concat_nont(nont, s):
+        return nont, s
+
+    for nont, box in rsa.boxes.items():
+        dfa = box.dfa
+
+        for s in dfa.final_states | dfa.start_states:
+            if s in dfa.final_states:
+                nfa_of_rsm.add_final_state(concat_nont(nont, s))
+            if s in dfa.start_states:
+                nfa_of_rsm.add_start_state(concat_nont(nont, s))
+
+        for u, v, label in dfa.to_networkx().edges(data="label"):
+            nfa_of_rsm.add_transition(concat_nont(nont, u), label, concat_nont(nont, v))
+
+    adj_rsa = AdjacencyMatrixFA(nfa_of_rsm)
+    adj_graph = AdjacencyMatrixFA(graph_to_nfa(graph, start_nodes, final_nodes))
+
+    for nont in rsa.boxes:
+        for adj in (adj_graph, adj_rsa):
+            if nont not in adj.adjacency_matrixes_boolean_decomposition:
+                adj.adjacency_matrixes_boolean_decomposition[nont] = csr_matrix(
+                    (adj.state_count, adj.state_count), dtype=np.bool_
+                )
+
+    prev_nonzero_count = 0
+    new_nonzero_count = None
+
+    while prev_nonzero_count != new_nonzero_count:
+        prev_nonzero_count = new_nonzero_count
+        intersection = intersect_automata(adj_rsa, adj_graph)
+        transitive_closure = intersection.transitive_closure()
+        for row, column in zip(*transitive_closure.nonzero()):
+            row_state = intersection.state_of_indexes[row]
+            column_state = intersection.state_of_indexes[column]
+            try:
+                (row_symbol, row_rsm_state), row_graph_state = row_state
+                (column_symbol, column_rsm_state), column_graph_state = column_state
+            except ValueError:
+                continue
+            if (
+                row_symbol == column_symbol
+                and row_rsm_state in rsa.boxes[row_symbol].dfa.start_states
+                and column_rsm_state in rsa.boxes[row_symbol].dfa.final_states
+            ):
+                row_graph_index = adj_graph.index_of_states[row_graph_state]
+                column_graph_index = adj_graph.index_of_states[column_graph_state]
+
+                adj_graph.adjacency_matrixes_boolean_decomposition[row_symbol][
+                    row_graph_index, column_graph_index
+                ] = True
+
+        new_nonzero_count = sum(
+            adj_graph.adjacency_matrixes_boolean_decomposition[
+                nonterminal
+            ].count_nonzero()
+            for nonterminal in adj_graph.adjacency_matrixes_boolean_decomposition
+        )
+
+    res = set()
+    for n in adj_graph.start_states:
+        for m in adj_graph.final_states:
+            if adj_graph.adjacency_matrixes_boolean_decomposition[rsa.initial_label][
+                adj_graph.index_of_states[n], adj_graph.index_of_states[m]
+            ]:
+                res.add((n, m))
+    return res
+
+
+def cfg_to_rsm(cfg: pyformlang.cfg.CFG) -> pyformlang.rsa.RecursiveAutomaton:
+    return ebnf_to_rsm(cfg.to_text())
+
+
+def ebnf_to_rsm(ebnf: str) -> pyformlang.rsa.RecursiveAutomaton:
+    return pyformlang.rsa.RecursiveAutomaton.from_text(ebnf)