25,422 research outputs found
Incremental Parser Generation for Tree Adjoining Grammars
This paper describes the incremental generation of parse tables for the
LR-type parsing of Tree Adjoining Languages (TALs). The algorithm presented
handles modifications to the input grammar by updating the parser generated so
far. In this paper, a lazy generation of LR-type parsers for TALs is defined in
which parse tables are created by need while parsing. We then describe an
incremental parser generator for TALs which responds to modification of the
input grammar by updating parse tables built so far.Comment: 12 pages, 12 Postscript figures, uses fullname.st
Incremental View Maintenance For Collection Programming
In the context of incremental view maintenance (IVM), delta query derivation
is an essential technique for speeding up the processing of large, dynamic
datasets. The goal is to generate delta queries that, given a small change in
the input, can update the materialized view more efficiently than via
recomputation. In this work we propose the first solution for the efficient
incrementalization of positive nested relational calculus (NRC+) on bags (with
integer multiplicities). More precisely, we model the cost of NRC+ operators
and classify queries as efficiently incrementalizable if their delta has a
strictly lower cost than full re-evaluation. Then, we identify IncNRC+; a large
fragment of NRC+ that is efficiently incrementalizable and we provide a
semantics-preserving translation that takes any NRC+ query to a collection of
IncNRC+ queries. Furthermore, we prove that incremental maintenance for NRC+ is
within the complexity class NC0 and we showcase how recursive IVM, a technique
that has provided significant speedups over traditional IVM in the case of flat
queries [25], can also be applied to IncNRC+.Comment: 24 pages (12 pages plus appendix
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