Minimizing resources of sweeping and streaming string transducers

Félix Baschenis (1) , Olivier Gauwin (1) , Anca Muscholl (1) , Gabriele Puppis (1)

1 LaBRI - Laboratoire Bordelais de Recherche en Informatique

We consider minimization problems for natural parameters of word transducers: the number of passes performed by two-way transducers and the number of registers used by streaming transducers. We show how to compute in ExpSpace the minimum number of passes needed to implement a transduction given as sweeping transducer, and we provide effective constructions of transducers of (worst-case optimal) doubly exponential size. We then consider streaming transducers where concatenations of registers are forbidden in the register updates. Based on a correspondence between the number of passes of sweeping transducers and the number of registers of equivalent concatenation-free streaming transducers, we derive a minimization procedure for the number of registers of concatenation-free streaming transducers.

Mots clés: word transducers; streaming; 2-way; sweeping transducers; minimization

Domaines: Théorie et langage formel [cs.FL]

Félix Baschenis, Olivier Gauwin, Anca Muscholl, Gabriele Puppis. Minimizing resources of sweeping and streaming string transducers. 43rd International Colloquium on Automata, Languages, and Programming (ICALP 2016), Jul 2016, Rome, Italy. pp.114:1--114:14, ⟨10.4230/LIPIcs.ICALP.2016.114⟩. ⟨hal-01274992v3⟩