(2013) demonstrated orders of magnitude speedup in exact pattern matching with suffix arrays, the algorithms at the heart of on-demand extraction (Callison-Burch et al., 2005;Zhang and Vogel, 2005).
some popular translation models use "gappy" phrases (Chiang, 2007;Simard et al., 2005;Galley and Manning, 2010), and the GPU algorithm of He et al.