`expression`.`automaton(``algo``="auto")`

Generate an automaton from an expression.

The algo can be:

"auto": currently equivalent to "expansion", eventually should mix "standard" for basic expressions (faster) and "expansion" otherwise (more general).
"derivation": use derivation-based expression.derived_term, trim and stripped.
"derived_term": same as "expansion"
"expansion": use expansion-based expression.derived_term, trim and stripped.
"standard": use expression.standard.
"thompson": use expression.thompson.
"zpc": use expression.zpc, trim.
"zpc_compact": use expression.zpc, "compact" version, trim.

Examples



In [1]:

    
import vcsn
e = vcsn.Q.expression('\e+<2>a+<3>b')
e









    Out[1]:





$\varepsilon +  \left\langle 2 \right\rangle \,a +  \left\langle 3 \right\rangle \,b$



In [2]:

    
e.automaton('derived_term')









    Out[2]:



In [3]:

    
e.automaton('standard')









    Out[3]:



In [4]:

    
e.automaton('thompson')









    Out[4]:



In [5]:

    
e.automaton('zpc')









    Out[5]:



In [6]:

    
e.automaton('zpc_compact')









    Out[6]:

The automata are guaranteed to be trim, even if the algorithm used by automaton generated useless states.



In [7]:

    
e = vcsn.Q.expression('abc&abd')
e.derived_term()









    Out[7]:



In [8]:

    
e.automaton('derived_term')









    Out[8]:



In [9]:

    
e = vcsn.Q.expression('a?')
e.zpc()









    Out[9]:



In [10]:

    
e.automaton('zpc')









    Out[10]: