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.

Domaines: Théorie et langage formel [cs.FL]

Félix Baschenis, Olivier Gauwin, Anca Muscholl, Gabriele Puppis. Minimizing resources of sweeping and streaming string transducers. 2016. ⟨hal-01274992v1⟩