Skip to main content Accessibility help
×
×
Home

Efficient feature structure operations without compilation

  • ROBERT MALOUF (a1), JOHN CARROLL (a2) and ANN COPESTAKE (a3)
    • Published online: 01 November 2000
Abstract

One major obstacle to the efficient processing of large wide coverage grammars in unification-based grammatical frameworks such as HPSG is the time and space cost of the unification operation itself. In a grammar development system it is not appropriate to address this problem with techniques which involve lengthy compilation, since this slows down the edit-test-debug cycle. Nor is it possible to radically restructure the grammar. In this paper, we describe novel extensions to an existing efficient unification algorithm which improve its space and time behaviour (without affecting its correctness) by substantially increasing the amount of structure sharing that takes place. We also describe a fast and automatically tunable pre-unification filter (the ‘quick check’) which in practice detects a large proportion of unifications that if performed would fail. Finally, we present an efficient algorithm for checking for subsumption relationships between two feature structures; a special case of this gives a fast equality test. The subsumption check is used in a parser (described elsewhere in this issue) which ‘packs’ local ambiguities to avoid performing redundant sub-computations.

Copyright
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Natural Language Engineering
  • ISSN: 1351-3249
  • EISSN: 1469-8110
  • URL: /core/journals/natural-language-engineering
Please enter your name
Please enter a valid email address
Who would you like to send this to? *
×

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed