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733 lines
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733 lines
14 KiB
HTML
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
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<META NAME="generator" CONTENT="http://txt2tags.sf.net">
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<TITLE>The GF Resource Grammar Library Version 1.0</TITLE>
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</HEAD><BODY BGCOLOR="white" TEXT="black">
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<P ALIGN="center"><CENTER><H1>The GF Resource Grammar Library Version 1.0</H1>
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<FONT SIZE="4">
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<I>Author: Aarne Ranta <aarne (at) cs.chalmers.se></I><BR>
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Last update: Tue Mar 7 16:01:46 2006
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</FONT></CENTER>
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<P>
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<!-- NEW -->
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</P>
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<H2>Plan</H2>
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<P>
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Purpose
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</P>
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<P>
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Background
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</P>
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<P>
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Coverage
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</P>
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<P>
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Structure
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</P>
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<P>
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How to use
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</P>
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<P>
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How to implement a new language
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</P>
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<P>
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How to extend the API
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</P>
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<P>
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<!-- NEW -->
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</P>
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<H2>Purpose</H2>
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<H3>Library for applications</H3>
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<P>
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High-level access to grammatical rules
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</P>
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<P>
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E.g. <I>You have k new messages</I> rendered in ten languages <I>X</I>
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</P>
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<PRE>
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render X (Have (You (Number (k (New Message)))))
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</PRE>
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<P></P>
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<P>
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Usability for different purposes
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</P>
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<UL>
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<LI>translation systems
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<LI>software localization
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<LI>dialogue systems
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<LI>language teaching
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</UL>
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<P>
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<!-- NEW -->
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</P>
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<H3>Grammar as parser</H3>
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<P>
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Often in NLP, a grammar is just high-level code for a parser.
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</P>
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<P>
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But writing a grammar can be inadequate for parsing:
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</P>
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<UL>
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<LI>too much manual work
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<LI>too inefficient
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<LI>not robust
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<LI>too ambiguous
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</UL>
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<P>
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Moreover, a grammar fine-tuned for parsing may not be reusable
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</P>
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<UL>
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<LI>for generation
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<LI>for specialized grammars
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<LI>as library
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</UL>
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<P>
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<!-- NEW -->
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</P>
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<H3>Grammar as language definition</H3>
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<P>
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Linguistic ontology: <B>abstract syntax</B>
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</P>
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<P>
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E.g. adjectival modification
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</P>
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<PRE>
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AdjCN : AP -> CN -> CN ;
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</PRE>
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<P></P>
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<P>
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Rendering in different languages: <B>concrete syntax</B>
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</P>
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<P>
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Resource grammars have generation perspective, rather than parsing
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</P>
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<UL>
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<LI>abstract syntax serves as a key to expressions in different languages
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</UL>
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<P>
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<!-- NEW -->
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</P>
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<H3>Usability by non-linguists</H3>
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<P>
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Division of labour: resource grammars hide linguistic details
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</P>
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<P>
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Presentation: "school grammar" concepts, dictionary-like conventions
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</P>
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<P>
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API = Application Programmer's Interface
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</P>
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<P>
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Documentation: <CODE>gfdoc</CODE>
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</P>
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<P>
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IDE = Interactive Development Environment (forthcoming)
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</P>
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<P>
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Example-based grammar writing
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</P>
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<PRE>
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render Ita (parse Eng "you have k messages")
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</PRE>
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<P></P>
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<P>
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<!-- NEW -->
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</P>
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<H3>Scientific interest</H3>
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<P>
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Linguistics
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</P>
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<UL>
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<LI>definition of linguistic ontology
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<LI>coping with different problems in different languages
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<LI>sharing concrete-syntax code between languages
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<LI>creating a resource for other NLP applications
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</UL>
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<P>
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Computer science
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</P>
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<UL>
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<LI>datastructures for grammar rules
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<LI>type systems for grammars
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<LI>algorithms: parsing, generation, grammar compilation
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<LI>domain-specific programming language (GF)
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<LI>module system
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</UL>
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<P>
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<!-- NEW -->
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</P>
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<H2>Background</H2>
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<H3>History</H3>
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<P>
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2002: v. 0.2
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</P>
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<UL>
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<LI>English, French, German, Swedish
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</UL>
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<P>
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2003: v. 0.6
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</P>
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<UL>
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<LI>module system
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<LI>added Finnish, Italian, Russian
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<LI>used in KeY
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</UL>
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<P>
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2005: v. 0.9
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</P>
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<UL>
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<LI>tenses
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<LI>added Danish, Norwegian, Spanish; no German
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<LI>used in WebALT
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</UL>
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<P>
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2006: v. 1.0
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</P>
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<UL>
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<LI>approximate CLE coverage
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<LI>reorganized module system and implementation
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<LI>not yet (4/3/2006) for Danish and Russian
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</UL>
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<P>
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<!-- NEW -->
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</P>
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<H3>Authors</H3>
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<P>
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Janna Khegai (Russian modules, forthcoming),
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Bjorn Bringert (many Swadesh lexica),
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Carlos Gonzalia (Spanish cardinals),
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Partik Jansson (Swedish cardinals),
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Aarne Ranta.
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</P>
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<P>
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We are grateful for contributions and
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comments to several other people who have used this and
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the previous versions of the resource library, including
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Ana Bove,
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David Burke,
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Lauri Carlson,
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Gloria Casanellas,
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Karin Cavallin,
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Hans-Joachim Daniels,
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Kristofer Johannisson,
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Anni Laine,
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Wanjiku Ng'ang'a,
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Jordi Saludes.
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</P>
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<P>
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<!-- NEW -->
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</P>
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<H3>Related work</H3>
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<P>
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CLE (Core Language Engine,
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<A HREF="http://mitpress.mit.edu/catalog/item/default.asp?tid=7739&ttype=2">Book 1992</A>)
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</P>
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<UL>
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<LI>English, Swedish, French, Danish
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<LI>uses Definita Clause Grammars, implementation in Prolog
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<LI>coverage for SACTI corpus,
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<A HREF="http://www.cambridge.org/uk/catalogue/catalogue.asp?isbn=0521770777">Spoken Language Translator (2001)</A>
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<LI>grammar specialization via explanation-based learning
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</UL>
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<P>
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<A HREF="http://www.delph-in.net/matrix/">LinGO Grammar Matrix</A>
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</P>
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<UL>
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<LI>English, German, Japanese, Spanish, ...
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<LI>uses HPSG, implementation in LKB
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<LI>a check list for parallel grammar implementations
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</UL>
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<P>
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<A HREF="http://www2.parc.com/istl/groups/nltt/pargram/">Pargram</A>
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</P>
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<UL>
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<LI>Aimed: Arabic, Chinese, English, French, German, Hungarian, Japanese,
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Malagasy, Norwegian, Turkish, Urdu, Vietnamese, and Welsh
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<LI>uses LFG
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<LI>one set of big grammars, transfer rules
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</UL>
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<P>
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Rosetta Machine Translation (<A HREF="http://citeseer.ist.psu.edu/181924.html">Book 1994</A>)
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</P>
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<UL>
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<LI>Dutch, English, French
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<LI>uses M-grammars, compositional translation inspired by Montague
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<LI>compositional transfer rules
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</UL>
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<P>
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<!-- NEW -->
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</P>
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<H2>Coverage</H2>
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<H3>Languages</H3>
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<P>
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The current GF Resource Project covers ten languages:
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</P>
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<UL>
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<LI><CODE>Dan</CODE>ish
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<LI><CODE>Eng</CODE>lish
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<LI><CODE>Fin</CODE>nish
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<LI><CODE>Fre</CODE>nch
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<LI><CODE>Ger</CODE>man
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<LI><CODE>Ita</CODE>lian
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<LI><CODE>Nor</CODE>wegian (bokmål)
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<LI><CODE>Rus</CODE>sian
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<LI><CODE>Spa</CODE>nish
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<LI><CODE>Swe</CODE>dish
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</UL>
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<P>
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In addition, parts (morphology) of Arabic, Estonian, Latin, and Urdu
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</P>
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<P>
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API 1.0 not yet implemented for Danish and Russian
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</P>
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<P>
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<!-- NEW -->
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</P>
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<H3>Morphology and lexicon</H3>
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<P>
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Complete inflection engine
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</P>
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<UL>
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<LI>all word classes
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<LI>all forms
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<LI>all inflectional paradigms
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</UL>
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<P>
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Basic lexicon
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</P>
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<UL>
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<LI>100 structural words
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<LI>350 content words, mainly for testing
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<LI>these include the 207 <A HREF="http://en.wiktionary.org/wiki/Swadesh_List">Swadesh words</A>
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</UL>
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<P>
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It is more important to enable lexicon extensions than to
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provide a huge lexicon.
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</P>
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<UL>
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<LI>technical lexica can have very special words, which tend to be regular
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</UL>
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<P>
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<!-- NEW -->
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</P>
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<H3>Syntactic structures</H3>
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<P>
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Texts:
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sequences of phrases with punctuation
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</P>
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<P>
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Phrases:
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declaratives, questions, imperatives, vocatives
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</P>
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<P>
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Tense, mood, and polarity:
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present, past, future, conditional ; similtaneous, anterior ; positive, negative
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</P>
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<P>
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Questions:
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yes-no, "wh" ; direct, indirect
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</P>
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<P>
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Clauses:
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main, relative, embedded (subject, object, adverbial)
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</P>
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<P>
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Verb phrases:
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intransitive, transitive, ditransitive, prepositional
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</P>
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<P>
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Noun phrases:
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proper names, pronouns, determiners, possessives, cardinals and ordinals
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</P>
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<P>
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<!-- NEW -->
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</P>
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<H3>Quantitative measures</H3>
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<P>
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67 categories
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</P>
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<P>
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150 abstract syntax combination rules
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</P>
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<P>
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100 structural words
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</P>
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<P>
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350 content words in a test lexicon
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</P>
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<P>
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Lines of source code (4/3/2006):
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</P>
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<PRE>
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abstract 1131
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english 2344
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german 2386
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finnish 3396
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norwegian 1257
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swedish 1465
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scandinavian 1023
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french 3246 -- Besch + Irreg + Morpho 2111
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italian 7797 -- Besch 6512
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spanish 7120 -- Besch 5877
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romance 1066
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</PRE>
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<P></P>
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<P>
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<!-- NEW -->
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</P>
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<H2>Structure of the API</H2>
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<H3>Language-independent ground API</H3>
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<P>
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<IMG ALIGN="middle" SRC="Lang.png" BORDER="0" ALT="">
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</P>
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<P>
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<!-- NEW -->
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</P>
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<H3>The structure of a text sentence</H3>
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<PRE>
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John walks.
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TFullStop : Phr -> Text -> Text
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(PhrUtt : PConj -> Utt -> Voc -> Phr
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NoPConj
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(UttS : S -> Utt
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(UseCl : Tense -> Anter -> Pol -> Cl -> S
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TPres
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ASimul
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PPos
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(PredVP : NP -> VP -> Cl
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(UsePN : PN -> NP
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john_PN)
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(UseV : V -> VP
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walk_V))))
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NoVoc)
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TEmpty
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</PRE>
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<P></P>
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<P>
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<!-- NEW -->
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</P>
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<H3>Structure in syntax editor</H3>
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<P>
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<IMG ALIGN="middle" SRC="editor.png" BORDER="0" ALT="">
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</P>
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<P>
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<!-- NEW -->
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</P>
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<H3>Language-dependent paradigm modules</H3>
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<H4>Regular paradigms</H4>
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<P>
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Every language implements these regular patterns that take
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"dictionary forms" as arguments.
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</P>
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<PRE>
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regN : Str -> N
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regA : Str -> A
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regV : Str -> V
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</PRE>
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<P>
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Their usefulness varies. For instance, they
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all are quite good in Finnish and English.
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In Swedish, less so:
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</P>
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<PRE>
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regN "val" ---> val, valen, valar, valarna
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</PRE>
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<P>
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Initializing a lexicon with <CODE>regX</CODE>s is
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usually a good starting point in grammar development.
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</P>
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<P>
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<!-- NEW -->
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</P>
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<H4>Regular paradigms</H4>
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<P>
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In Swedish, giving the gender of <CODE>N</CODE> improves a lot
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</P>
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<PRE>
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regGenN "val" neutrum ---> val, valet, val, valen
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</PRE>
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<P></P>
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<P>
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There are also special constructs taking other forms:
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</P>
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<PRE>
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mk2N : (nyckel,nycklar : Str) -> N
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mk1N : (bilarna : Str) -> N
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irregV : (dricka, drack, druckit : Str) -> V
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</PRE>
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<P></P>
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<P>
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Regular verbs are actually implemented the
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<A HREF="http://lexin.nada.kth.se/sve-sve.shtml">Lexin</A> way
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</P>
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<PRE>
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regV : (talar : Str) -> N
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</PRE>
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<P></P>
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<P>
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<!-- NEW -->
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</P>
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<H4>Worst-case paradigms</H4>
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<P>
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To cover all situations, worst-case paradigms are given. E.g. Swedish
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</P>
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<PRE>
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mkN : (apa,apan,apor,aporna : Str) -> N
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mkA : (liten, litet, lilla, sma, mindre, minst, minsta : Str) -> A
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mkV : (supa,super,sup,söp,supit,supen : Str) -> V
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</PRE>
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<P></P>
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<P>
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<!-- NEW -->
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</P>
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<H4>Irregular words</H4>
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<P>
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Iregular words in <CODE>IrregX</CODE>, e.g. Swedish:
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</P>
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<PRE>
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draga_V : V =
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mkV (variants { "dra"; "draga"}) (variants { "drar" ; "drager"})
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(variants { "dra" ; "drag" }) "drog" "dragit" "dragen" ;
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</PRE>
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<P>
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Goal: eliminate the user's need of worst-case functions.
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</P>
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<P>
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<!-- NEW -->
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</P>
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<H3>Language-dependent syntax extensions</H3>
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<P>
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<!-- NEW -->
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</P>
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<H3>Special-purpose APIs</H3>
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<P>
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Syntactic structures that are not shared by all languages.
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</P>
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<P>
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Not implemented yet.
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</P>
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<P>
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Candidates:
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</P>
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<UL>
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<LI><CODE>Nor</CODE> post-possessives: <CODE>bilen min</CODE>
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<LI><CODE>Fre</CODE> question forms: <CODE>est-ce que tu dors ?</CODE>
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</UL>
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<P>
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<!-- NEW -->
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</P>
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<H3>How to use as top-level grammar</H3>
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<P>
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<!-- NEW -->
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</P>
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<H3>Compiling</H3>
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<P>
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It is a good idea to compile the library, so that it can be opened faster
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</P>
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<PRE>
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GF/lib/resource-1.0% make
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writes GF/lib/alltenses
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GF/lib/present
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GF/lib/resource-1.0/langs.gfcm
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</PRE>
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<P>
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If you don't intend to change the library, you never need to process the source
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files again. Just do some of
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</P>
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<PRE>
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gf -nocf langs.gfcm -- all 8 languages
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gf -nocf -path=alltenses:prelude alltenses/LangSwe.gfc -- Swedish only
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gf -nocf -path=alltenses:prelude present/LangSwe.gfc -- Swedish only, present tense only
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</PRE>
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|
<P></P>
|
|
<P>
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|
<!-- NEW -->
|
|
</P>
|
|
<H3>Parsing</H3>
|
|
<P>
|
|
The default parser does not work!
|
|
</P>
|
|
<P>
|
|
The MCFG parser works in some languages, after waiting appr. 20 seconds
|
|
</P>
|
|
<PRE>
|
|
p -mcfg -lang=LangEng -cat=S "I would see her"
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|
|
|
p -mcfg -lang=LangSwe -cat=S "jag skulle se henne"
|
|
|
|
p -mcfg -lang=LangNor -cat=S "jeg ville se henne"
|
|
|
|
</PRE>
|
|
<P>
|
|
Parsing in <CODE>present/</CODE> versions is quicker.
|
|
</P>
|
|
<P>
|
|
<!-- NEW -->
|
|
</P>
|
|
<H3>Treebank generation</H3>
|
|
<P>
|
|
Multilingual treebank entry = tree + linearizations
|
|
</P>
|
|
<P>
|
|
Some examples on treebank generation, assuming <CODE>langs.gfcm</CODE>
|
|
</P>
|
|
<PRE>
|
|
gr -cat=S -number=10 -cf | tb -- 10 random S
|
|
|
|
gt -cat=Phr -depth=4 | tb -xml | wf ex.xml -- all Phr to depth 4, into file ex.xml
|
|
</PRE>
|
|
<P>
|
|
Regression testing
|
|
</P>
|
|
<PRE>
|
|
rf ex.xml | tb -c -- read treebank from file and compare to present grammars
|
|
</PRE>
|
|
<P>
|
|
Updating a treebank
|
|
</P>
|
|
<PRE>
|
|
rf old.xml | tb -trees | tb -xml | wf new.xml -- read old from file, write new to file
|
|
</PRE>
|
|
<P></P>
|
|
<P>
|
|
<!-- NEW -->
|
|
</P>
|
|
<H3>Treebank-based parsing</H3>
|
|
<P>
|
|
Brute-force method that helps if real parsing is more expensive.
|
|
</P>
|
|
<PRE>
|
|
make treebank -- make treebank with all languages
|
|
|
|
gf -treebank langs.xml -- start GF by reading the treebank
|
|
|
|
> ut -strings -treebank=LangIta -- show all Ita strings
|
|
|
|
> ut -treebank=LangIta -raw "Quello non si romperebbe" -- look up a string
|
|
|
|
> i -nocf langs.gfcm -- read grammar to be able to linearize
|
|
|
|
> ut -treebank=LangIta "Quello non si romperebbe" | l -multi -- translate to all
|
|
</PRE>
|
|
<P></P>
|
|
<P>
|
|
<!-- NEW -->
|
|
</P>
|
|
<H3>Morphology</H3>
|
|
<P>
|
|
Use morphological analyser
|
|
</P>
|
|
<PRE>
|
|
gf -nocf -retain -path=alltenses:prelude alltenses/LangSwe.gf
|
|
> ma "jag kan inte höra vad du säger"
|
|
</PRE>
|
|
<P></P>
|
|
<P>
|
|
Try out a morphology quiz
|
|
</P>
|
|
<PRE>
|
|
> mq -cat=V
|
|
</PRE>
|
|
<P></P>
|
|
<P>
|
|
Try out inflection patterns
|
|
</P>
|
|
<PRE>
|
|
gf -retain -path=alltenses:prelude alltenses/ParadigmsSwe.gfr
|
|
> cc regV "lyser"
|
|
</PRE>
|
|
<P></P>
|
|
<P>
|
|
<!-- NEW -->
|
|
</P>
|
|
<P>
|
|
<!-- NEW -->
|
|
</P>
|
|
<H3>Syntax editing</H3>
|
|
<P>
|
|
We start a demo by
|
|
</P>
|
|
<PRE>
|
|
gfeditor langs.gfcm
|
|
</PRE>
|
|
<P></P>
|
|
<P>
|
|
<IMG ALIGN="middle" SRC="editor.png" BORDER="0" ALT="">
|
|
</P>
|
|
<P>
|
|
<!-- NEW -->
|
|
</P>
|
|
<H3>Efficient parsing via application grammar</H3>
|
|
<P>
|
|
<!-- NEW -->
|
|
</P>
|
|
<H2>How to use as library</H2>
|
|
<H3>Specialization through parametrized modules</H3>
|
|
<P>
|
|
<!-- NEW -->
|
|
</P>
|
|
<H3>Compile-time transfer</H3>
|
|
<P>
|
|
<!-- NEW -->
|
|
</P>
|
|
<H3>A natural division into modules</H3>
|
|
<P>
|
|
<!-- NEW -->
|
|
</P>
|
|
<H3>Example-based grammar writing</H3>
|
|
<P>
|
|
<!-- NEW -->
|
|
</P>
|
|
<H2>How to implement a new language</H2>
|
|
<H3>Ordinary modules</H3>
|
|
<P>
|
|
<!-- NEW -->
|
|
</P>
|
|
<H3>Parametrized modules</H3>
|
|
<P>
|
|
<!-- NEW -->
|
|
</P>
|
|
<H3>The kernel of the API</H3>
|
|
<P>
|
|
<!-- NEW -->
|
|
</P>
|
|
<H3>How to proceed</H3>
|
|
<P>
|
|
<!-- NEW -->
|
|
</P>
|
|
<H2>How to extend the API</H2>
|
|
<P>
|
|
<!-- NEW -->
|
|
</P>
|
|
<H3>Extend old modules or add a new one?</H3>
|
|
|
|
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