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diff --git a/doc/transfer-tutorial.html b/doc/transfer-tutorial.html new file mode 100644 index 000000000..7ca1c2060 --- /dev/null +++ b/doc/transfer-tutorial.html @@ -0,0 +1,210 @@ +<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> +<HTML> +<HEAD> +<META NAME="generator" CONTENT="http://txt2tags.sf.net"> +<TITLE>Transfer tutorial</TITLE> +</HEAD><BODY BGCOLOR="white" TEXT="black"> +<P ALIGN="center"><CENTER><H1>Transfer tutorial</H1> +<FONT SIZE="4"> +<I>Author: Björn Bringert <bringert@cs.chalmers.se></I><BR> +Last update: Tue Dec 6 14:26:07 2005 +</FONT></CENTER> + +<P></P> +<HR NOSHADE SIZE=1> +<P></P> + <UL> + <LI><A HREF="#toc1">Objective</A> + <LI><A HREF="#toc2">Abstract syntax</A> + <LI><A HREF="#toc3">Concrete syntax</A> + <LI><A HREF="#toc4">Generate tree module</A> + <LI><A HREF="#toc5">Write transfer code</A> + <LI><A HREF="#toc6">Compiling Transfer programs</A> + <LI><A HREF="#toc7">Using Transfer programs in GF</A> + <UL> + <LI><A HREF="#toc8">Loading the grammars</A> + <LI><A HREF="#toc9">Loading the Transfer program</A> + <LI><A HREF="#toc10">Calling Transfer functions</A> + <UL> + <LI><A HREF="#toc11">Transfer between different abstract syntaxes</A> + </UL> + </UL> + </UL> + +<P></P> +<HR NOSHADE SIZE=1> +<P></P> +<A NAME="toc1"></A> +<H1>Objective</H1> +<P> +We want to write a Transfer program which we can use to do aggregation +in sentences which use conjugations on the sentence, noun phrase and +verb phrase levels. For example, we want to be able to transform +the sentence "John walks and Mary walks" to the sentence +"John and Mary walk". We would also like to transform +"John walks and John swims" to "John walks and swims". +</P> +<P> +Thus that what we want to do is: +</P> +<UL> +<LI>Transform sentence conjugation where the verb phrases in the sentences + are identical to noun phrase conjugation. +<LI>Transform sentence conjugation where the noun phrases in the sentences + are identical to verb phrase conjugation. +</UL> + +<P> +This needs to be done recursively and thoughout the sentence, to be +able to handle cases like "John walks and Mary walks and Bill walks", and +"John runs and Mary walks and Bill walks". +</P> +<P> +FIXME: what about John walks and Mary runs and Bill walks"? +</P> +<A NAME="toc2"></A> +<H1>Abstract syntax</H1> +<P> +We will use the abstract syntax defined in +<A HREF="../transfer/examples/aggregation/Abstract.gf">Abstract.gf</A>. +</P> +<A NAME="toc3"></A> +<H1>Concrete syntax</H1> +<P> +There is an English concrete syntax for this grammar in +<A HREF="../transfer/examples/aggregation/English.gf">English.gf</A>. +</P> +<A NAME="toc4"></A> +<H1>Generate tree module</H1> +<P> +To be able to write Transfer programs which sue the types defined in +an abstract syntax, we first need to generate a Transfer file with +a data type defintition corresponding to the abstract syntax. +This is done with the <CODE>transfer</CODE> grammar printer: +</P> +<PRE> + $ gf + > i English.gf + > pg -printer=transfer | wf tree.tr +</PRE> +<P></P> +<P> +Note that you need to load a concrete syntax which uses the abstract +syntax that you want to create a Transfer data type for. Loading just the +abstract syntax module is not enough. FIXME: why? +</P> +<P> +The command sequence above writes a Transfer data type definition to the +file <CODE>tree.tr</CODE>. +</P> +<A NAME="toc5"></A> +<H1>Write transfer code</H1> +<P> +We write the Transfer program +<A HREF="../transfer/examples/aggregation/aggregate.tr">aggregate.tr</A>. +</P> +<P> +FIXME: explain the code +</P> +<A NAME="toc6"></A> +<H1>Compiling Transfer programs</H1> +<P> +Transfer programs are written in the human-friendly Transfer language, +but GF only understands the simpler Transfer Core language. Therefore, +before using a Transfer program, you must first compile it to +Transfer Core. This is done using the <CODE>transferc</CODE> command: +</P> +<PRE> + $ transferc -i<lib> <transfer program> +</PRE> +<P></P> +<P> +Here, <CODE><lib></CODE> is the path to search for any modules which you import +in your Transfer program. You can give several <CODE>-i</CODE> flags. +</P> +<P> +So, to compile <CODE>aggregate.tr</CODE> which we created above, we use: +</P> +<PRE> + $ transferc aggregate.tr +</PRE> +<P></P> +<P> +The creates the Transfer Core file <CODE>aggregate.trc</CODE>. +</P> +<A NAME="toc7"></A> +<H1>Using Transfer programs in GF</H1> +<A NAME="toc8"></A> +<H2>Loading the grammars</H2> +<P> +To use a Transfer Core program to transform abstract syntax terms +in GF, you must first load the grammars which you want to use the +program with. For the example above, we need the grammar <CODE>English.gf</CODE> +and its dependencies. We load this grammar with: +</P> +<PRE> + > i English.gf +</PRE> +<P></P> +<A NAME="toc9"></A> +<H2>Loading the Transfer program</H2> +<P> +There are two steps to using a Transfer Core program in GF. First you load +the program into GF. This is done with the <CODE>i</CODE> command, which is also +used when loading grammar modules. To load the <CODE>aggregate.trc</CODE> which +we created above, we use: +</P> +<PRE> + > i aggregate.trc +</PRE> +<P></P> +<A NAME="toc10"></A> +<H2>Calling Transfer functions</H2> +<P> +To call a Transfer function on a term, we use the <CODE>at</CODE> command. +The <CODE>at</CODE> command takes the name of a Transfer function and an abstract +syntax term, and applies the function to the term: +</P> +<PRE> + > at aggregS ConjS And (Pred John Walk) (Pred Mary Walk) + + Pred (ConjNP And John Mary) Walk +</PRE> +<P></P> +<P> +Of course, the input and output terms of the <CODE>at</CODE> command can +be read from and written to pipes: +</P> +<PRE> + > p "John walks and Mary walks" | at aggregS | l + + John and Mary walk +</PRE> +<P></P> +<P> +To see what is going on between the steps, we can use <CODE>-tr</CODE> flags +to the commands: +</P> +<PRE> + > p -tr "John walks and Mary walks" | at -tr aggregS | l + + ConjS And (Pred John Walk) (Pred Mary Walk) + + Pred (ConjNP And John Mary) Walk + + John and Mary walk +</PRE> +<P></P> +<A NAME="toc11"></A> +<H3>Transfer between different abstract syntaxes</H3> +<P> +If the transfer function which you wan to call takes as input a term in one +abstract syntax, and returns a term in a different abstract syntax, you +can use the <CODE>-lang</CODE> flag with the <CODE>at</CODE> command. This is needed since the +<CODE>at</CODE> command type checks the result it produces, and it needs to +know which abstract sytnax to type check it in. +</P> + +<!-- html code generated by txt2tags 2.0 (http://txt2tags.sf.net) --> +<!-- cmdline: txt2tags darcs.txt transfer-reference.txt transfer-tutorial.txt transfer.txt --> +</BODY></HTML> |