html version generated

doc/tutorial/gf-tutorial2.html

@@ -7,7 +7,7 @@
 <P ALIGN="center"><CENTER><H1>Grammatical Framework Tutorial</H1>
 <FONT SIZE="4">
 <I>Author: Aarne Ranta &lt;aarne (at) cs.chalmers.se&gt;</I><BR>
-Last update: Mon Dec 19 18:05:36 2005
+Last update: Wed Dec 21 10:29:13 2005
 </FONT></CENTER>
 
 <P></P>
@@ -91,36 +91,38 @@ Last update: Mon Dec 19 18:05:36 2005
       <LI><A HREF="#toc58">Free variation</A>
       <LI><A HREF="#toc59">Record extension and subtyping</A>
       <LI><A HREF="#toc60">Tuples and product types</A>
-      <LI><A HREF="#toc61">Prefix-dependent choices</A>
+      <LI><A HREF="#toc61">Record and tuple patterns</A>
-      <LI><A HREF="#toc62">Predefined types and operations</A>
+      <LI><A HREF="#toc62">Prefix-dependent choices</A>
+      <LI><A HREF="#toc63">Predefined types and operations</A>
       </UL>
-    <LI><A HREF="#toc63">More features of the module system</A>
+    <LI><A HREF="#toc64">More features of the module system</A>
       <UL>
-      <LI><A HREF="#toc64">Interfaces, instances, and functors</A>
+      <LI><A HREF="#toc65">Interfaces, instances, and functors</A>
-      <LI><A HREF="#toc65">Resource grammars and their reuse</A>
+      <LI><A HREF="#toc66">Resource grammars and their reuse</A>
-      <LI><A HREF="#toc66">Restricted inheritance and qualified opening</A>
+      <LI><A HREF="#toc67">Restricted inheritance and qualified opening</A>
       </UL>
-    <LI><A HREF="#toc67">More concepts of abstract syntax</A>
+    <LI><A HREF="#toc68">More concepts of abstract syntax</A>
       <UL>
-      <LI><A HREF="#toc68">Dependent types</A>
+      <LI><A HREF="#toc69">Dependent types</A>
-      <LI><A HREF="#toc69">Higher-order abstract syntax</A>
+      <LI><A HREF="#toc70">Higher-order abstract syntax</A>
-      <LI><A HREF="#toc70">Semantic definitions</A>
+      <LI><A HREF="#toc71">Semantic definitions</A>
+      <LI><A HREF="#toc72">List categories</A>
       </UL>
-    <LI><A HREF="#toc71">Transfer modules</A>
+    <LI><A HREF="#toc73">Transfer modules</A>
-    <LI><A HREF="#toc72">Practical issues</A>
+    <LI><A HREF="#toc74">Practical issues</A>
       <UL>
-      <LI><A HREF="#toc73">Lexers and unlexers</A>
+      <LI><A HREF="#toc75">Lexers and unlexers</A>
-      <LI><A HREF="#toc74">Efficiency of grammars</A>
+      <LI><A HREF="#toc76">Efficiency of grammars</A>
-      <LI><A HREF="#toc75">Speech input and output</A>
+      <LI><A HREF="#toc77">Speech input and output</A>
-      <LI><A HREF="#toc76">Multilingual syntax editor</A>
+      <LI><A HREF="#toc78">Multilingual syntax editor</A>
-      <LI><A HREF="#toc77">Interactive Development Environment (IDE)</A>
+      <LI><A HREF="#toc79">Interactive Development Environment (IDE)</A>
-      <LI><A HREF="#toc78">Communicating with GF</A>
+      <LI><A HREF="#toc80">Communicating with GF</A>
-      <LI><A HREF="#toc79">Embedded grammars in Haskell, Java, and Prolog</A>
+      <LI><A HREF="#toc81">Embedded grammars in Haskell, Java, and Prolog</A>
-      <LI><A HREF="#toc80">Alternative input and output grammar formats</A>
+      <LI><A HREF="#toc82">Alternative input and output grammar formats</A>
       </UL>
-    <LI><A HREF="#toc81">Case studies</A>
+    <LI><A HREF="#toc83">Case studies</A>
       <UL>
-      <LI><A HREF="#toc82">Interfacing formal and natural languages</A>
+      <LI><A HREF="#toc84">Interfacing formal and natural languages</A>
       </UL>
     </UL>
 
@@ -1996,6 +1998,44 @@ Product types and tuples are syntactic sugar for record types and records:
 Thus the labels <CODE>p1, p2,...`</CODE> are hard-coded.
 </P>
 <A NAME="toc61"></A>
+<H3>Record and tuple patterns</H3>
+<P>
+Record types of parameter types are also parameter types.
+A typical example is a record of agreement features, e.g. French
+</P>
+<PRE>
+    oper Agr : PType = {g : Gender ; n : Number ; p : Person} ;
+</PRE>
+<P>
+Notice the term <CODE>PType</CODE> rather than just <CODE>Type</CODE> referring to
+parameter types. Every <CODE>PType</CODE> is also a <CODE>Type</CODE>.
+</P>
+<P>
+Pattern matching is done in the expected way, but it can moreover
+utilize partial records: the branch
+</P>
+<PRE>
+    {g = Fem} =&gt; t
+</PRE>
+<P>
+in a table of type <CODE>Agr =&gt; T</CODE> means the same as
+</P>
+<PRE>
+    {g = Fem ; n = _ ; p = _} =&gt; t
+</PRE>
+<P>
+Tuple patterns are translated to record patterns in the
+same way as tuples to records; partial patterns make it
+possible to write, slightly surprisingly,
+</P>
+<PRE>
+    case &lt;g,n,p&gt; of {
+      &lt;Fem&gt; =&gt; t
+      ...
+      }
+</PRE>
+<P></P>
+<A NAME="toc62"></A>
 <H3>Prefix-dependent choices</H3>
 <P>
 The construct exemplified in
@@ -2024,7 +2064,7 @@ This very example does not work in all situations: the prefix
           } ;
 </PRE>
 <P></P>
-<A NAME="toc62"></A>
+<A NAME="toc63"></A>
 <H3>Predefined types and operations</H3>
 <P>
 GF has the following predefined categories in abstract syntax:
@@ -2047,11 +2087,11 @@ they can be used as arguments. For example:
     -- e.g. (StreetAddress 10 "Downing Street") : Address
 </PRE>
 <P></P>
-<A NAME="toc63"></A>
-<H2>More features of the module system</H2>
 <A NAME="toc64"></A>
-<H3>Interfaces, instances, and functors</H3>
+<H2>More features of the module system</H2>
 <A NAME="toc65"></A>
+<H3>Interfaces, instances, and functors</H3>
+<A NAME="toc66"></A>
 <H3>Resource grammars and their reuse</H3>
 <P>
 A resource grammar is a grammar built on linguistic grounds,
@@ -2104,17 +2144,19 @@ The rest of the modules (black) come from the resource.
 <P>
 <IMG ALIGN="middle" SRC="Multi.png" BORDER="0" ALT="">
 </P>
-<A NAME="toc66"></A>
-<H3>Restricted inheritance and qualified opening</H3>
 <A NAME="toc67"></A>
-<H2>More concepts of abstract syntax</H2>
+<H3>Restricted inheritance and qualified opening</H3>
 <A NAME="toc68"></A>
-<H3>Dependent types</H3>
+<H2>More concepts of abstract syntax</H2>
 <A NAME="toc69"></A>
-<H3>Higher-order abstract syntax</H3>
+<H3>Dependent types</H3>
 <A NAME="toc70"></A>
-<H3>Semantic definitions</H3>
+<H3>Higher-order abstract syntax</H3>
 <A NAME="toc71"></A>
+<H3>Semantic definitions</H3>
+<A NAME="toc72"></A>
+<H3>List categories</H3>
+<A NAME="toc73"></A>
 <H2>Transfer modules</H2>
 <P>
 Transfer means noncompositional tree-transforming operations.
@@ -2133,9 +2175,9 @@ See the
 <A HREF="../transfer.html">transfer language documentation</A>
 for more information.
 </P>
-<A NAME="toc72"></A>
+<A NAME="toc74"></A>
 <H2>Practical issues</H2>
-<A NAME="toc73"></A>
+<A NAME="toc75"></A>
 <H3>Lexers and unlexers</H3>
 <P>
 Lexers and unlexers can be chosen from
@@ -2171,7 +2213,7 @@ Given by <CODE>help -lexer</CODE>, <CODE>help -unlexer</CODE>:
   
 </PRE>
 <P></P>
-<A NAME="toc74"></A>
+<A NAME="toc76"></A>
 <H3>Efficiency of grammars</H3>
 <P>
 Issues:
@@ -2182,7 +2224,7 @@ Issues:
 <LI>parsing efficiency: <CODE>-mcfg</CODE> vs. others
 </UL>
 
-<A NAME="toc75"></A>
+<A NAME="toc77"></A>
 <H3>Speech input and output</H3>
 <P>
 The<CODE>speak_aloud = sa</CODE> command sends a string to the speech
@@ -2212,7 +2254,7 @@ The method words only for grammars of English.
 Both Flite and ATK are freely available through the links
 above, but they are not distributed together with GF.
 </P>
-<A NAME="toc76"></A>
+<A NAME="toc78"></A>
 <H3>Multilingual syntax editor</H3>
 <P>
 The 
@@ -2229,18 +2271,29 @@ Here is a snapshot of the editor:
 The grammars of the snapshot are from the
 <A HREF="http://www.cs.chalmers.se/~aarne/GF/examples/letter">Letter grammar package</A>.
 </P>
-<A NAME="toc77"></A>
+<A NAME="toc79"></A>
 <H3>Interactive Development Environment (IDE)</H3>
 <P>
 Forthcoming.
 </P>
-<A NAME="toc78"></A>
+<A NAME="toc80"></A>
 <H3>Communicating with GF</H3>
 <P>
 Other processes can communicate with the GF command interpreter,
-and also with the GF syntax editor.
+and also with the GF syntax editor. Useful flags when invoking GF are
 </P>
-<A NAME="toc79"></A>
+<UL>
+<LI><CODE>-batch</CODE> suppresses the promps and structures the communication with XML tags.
+<LI><CODE>-s</CODE> suppresses non-output non-error messages and XML tags.
+-- <CODE>-nocpu</CODE> suppresses CPU time indication.
+<P></P>
+Thus the most silent way to invoke GF is
+<PRE>
+    gf -batch -s -nocpu
+</PRE>
+</UL>
+
+<A NAME="toc81"></A>
 <H3>Embedded grammars in Haskell, Java, and Prolog</H3>
 <P>
 GF grammars can be used as parts of programs written in the
@@ -2252,15 +2305,15 @@ following languages. The links give more documentation.
 <LI><A HREF="http://www.cs.chalmers.se/~peb/software.html">Prolog</A>
 </UL>
 
-<A NAME="toc80"></A>
+<A NAME="toc82"></A>
 <H3>Alternative input and output grammar formats</H3>
 <P>
 A summary is given in the following chart of GF grammar compiler phases:
 <IMG ALIGN="middle" SRC="../gf-compiler.png" BORDER="0" ALT="">
 </P>
-<A NAME="toc81"></A>
+<A NAME="toc83"></A>
 <H2>Case studies</H2>
-<A NAME="toc82"></A>
+<A NAME="toc84"></A>
 <H3>Interfacing formal and natural languages</H3>
 <P>
 <A HREF="http://www.cs.chalmers.se/~krijo/thesis/thesisA4.pdf">Formal and Informal Software Specifications</A>,
@@ -2273,6 +2326,6 @@ English and German.
 A simpler example will be explained here.
 </P>
 
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