examples added

bmoyer · bmoyer · commit 48bdf129a16b · 2014-06-29T16:00:45.000-04:00
diff --git a/example2.py b/example2.py
@@ -0,0 +1,27 @@
+"""This is an example of using a PDA to parse strings with
+well-formed parentheses."""
+from PDA import *
+from State import *
+
+accept5 = State(state_type="Accept")
+pop4 = State(state_type="Pop")
+pop3 = State(state_type="Pop")
+push2 = State(state_type="Push")
+read1 = State(state_type="Read")
+
+# add transitions for 'a', 'b', and the 'end' of the tape.
+read1.add_transition(push2, character="(")
+read1.add_transition(pop3, character=")")
+read1.add_transition(pop4, character="!")
+
+push2.add_transition(read1, character="X")
+pop3.add_transition(read1, character="X")
+
+pop4.add_transition(accept5, character="!")
+
+start_state = State(state_type="Start", next_state=read1)
+
+my_pda = PDA(start_state)
+
+tape_word = "(((((((()))(((())))()()((())))))))!"
+my_pda.start(tape=tape_word, stack=['!'], verbose=False)
