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doc/tutorial/gf-tutorial2.html
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@@ -7,7 +7,7 @@
<P ALIGN="center"><CENTER><H1>Grammatical Framework Tutorial</H1> <P ALIGN="center"><CENTER><H1>Grammatical Framework Tutorial</H1>
<FONT SIZE="4"> <FONT SIZE="4">
<I>Author: Aarne Ranta &lt;aarne (at) cs.chalmers.se&gt;</I><BR> <I>Author: Aarne Ranta &lt;aarne (at) cs.chalmers.se&gt;</I><BR>
Last update: Wed Dec 21 10:29:13 2005 Last update: Sat Jan 7 21:51:56 2006
</FONT></CENTER> </FONT></CENTER>
<P></P> <P></P>
@@ -92,37 +92,38 @@ Last update: Wed Dec 21 10:29:13 2005
<LI><A HREF="#toc59">Record extension and subtyping</A> <LI><A HREF="#toc59">Record extension and subtyping</A>
<LI><A HREF="#toc60">Tuples and product types</A> <LI><A HREF="#toc60">Tuples and product types</A>
<LI><A HREF="#toc61">Record and tuple patterns</A> <LI><A HREF="#toc61">Record and tuple patterns</A>
<LI><A HREF="#toc62">Prefix-dependent choices</A> <LI><A HREF="#toc62">Regular expression patterns</A>
<LI><A HREF="#toc63">Predefined types and operations</A> <LI><A HREF="#toc63">Prefix-dependent choices</A>
<LI><A HREF="#toc64">Predefined types and operations</A>
</UL> </UL>
<LI><A HREF="#toc64">More features of the module system</A> <LI><A HREF="#toc65">More features of the module system</A>
<UL> <UL>
<LI><A HREF="#toc65">Interfaces, instances, and functors</A> <LI><A HREF="#toc66">Interfaces, instances, and functors</A>
<LI><A HREF="#toc66">Resource grammars and their reuse</A> <LI><A HREF="#toc67">Resource grammars and their reuse</A>
<LI><A HREF="#toc67">Restricted inheritance and qualified opening</A> <LI><A HREF="#toc68">Restricted inheritance and qualified opening</A>
</UL> </UL>
<LI><A HREF="#toc68">More concepts of abstract syntax</A> <LI><A HREF="#toc69">More concepts of abstract syntax</A>
<UL> <UL>
<LI><A HREF="#toc69">Dependent types</A> <LI><A HREF="#toc70">Dependent types</A>
<LI><A HREF="#toc70">Higher-order abstract syntax</A> <LI><A HREF="#toc71">Higher-order abstract syntax</A>
<LI><A HREF="#toc71">Semantic definitions</A> <LI><A HREF="#toc72">Semantic definitions</A>
<LI><A HREF="#toc72">List categories</A> <LI><A HREF="#toc73">List categories</A>
</UL> </UL>
<LI><A HREF="#toc73">Transfer modules</A> <LI><A HREF="#toc74">Transfer modules</A>
<LI><A HREF="#toc74">Practical issues</A> <LI><A HREF="#toc75">Practical issues</A>
<UL> <UL>
<LI><A HREF="#toc75">Lexers and unlexers</A> <LI><A HREF="#toc76">Lexers and unlexers</A>
<LI><A HREF="#toc76">Efficiency of grammars</A> <LI><A HREF="#toc77">Efficiency of grammars</A>
<LI><A HREF="#toc77">Speech input and output</A> <LI><A HREF="#toc78">Speech input and output</A>
<LI><A HREF="#toc78">Multilingual syntax editor</A> <LI><A HREF="#toc79">Multilingual syntax editor</A>
<LI><A HREF="#toc79">Interactive Development Environment (IDE)</A> <LI><A HREF="#toc80">Interactive Development Environment (IDE)</A>
<LI><A HREF="#toc80">Communicating with GF</A> <LI><A HREF="#toc81">Communicating with GF</A>
<LI><A HREF="#toc81">Embedded grammars in Haskell, Java, and Prolog</A> <LI><A HREF="#toc82">Embedded grammars in Haskell, Java, and Prolog</A>
<LI><A HREF="#toc82">Alternative input and output grammar formats</A> <LI><A HREF="#toc83">Alternative input and output grammar formats</A>
</UL> </UL>
<LI><A HREF="#toc83">Case studies</A> <LI><A HREF="#toc84">Case studies</A>
<UL> <UL>
<LI><A HREF="#toc84">Interfacing formal and natural languages</A> <LI><A HREF="#toc85">Interfacing formal and natural languages</A>
</UL> </UL>
</UL> </UL>
@@ -2036,6 +2037,71 @@ possible to write, slightly surprisingly,
</PRE> </PRE>
<P></P> <P></P>
<A NAME="toc62"></A> <A NAME="toc62"></A>
<H3>Regular expression patterns</H3>
<P>
(New since 7 January 2006.)
</P>
<P>
To define string operations computed at compile time, such
as in morphology, it is handy to use regular expression patterns:
</P>
<UL>
<LI><I>p</I> <CODE>+</CODE> <I>q</I> : token consisting of <I>p</I> followed by <I>q</I>
<LI><I>p</I> <CODE>*</CODE> : token <I>p</I> repeated 0 or more times
(max the length of the string to be matched)
<LI><CODE>-</CODE> <I>p</I> : matches anything that <I>p</I> does not match
<LI><I>x</I> <CODE>@</CODE> <I>p</I> : bind to <I>x</I> what <I>p</I> matches
<LI><I>p</I> <CODE>|</CODE> <I>q</I> : matches what either <I>p</I> or <I>q</I> matches
</UL>
<P>
The last three apply to all types of patterns, the first two only to token strings.
Example: plural formation in Swedish 2nd declension
(<I>pojke-pojkar, nyckel-nycklar, seger-segrar, bil-bilar</I>):
</P>
<PRE>
plural2 : Str -&gt; Str = \w -&gt; case w of {
pojk + "e" =&gt; pojk + "ar" ;
nyck + "e" + l@("l" | "r" | "n") =&gt; nyck + l + "ar" ;
bil =&gt; bil + "ar"
} ;
</PRE>
<P>
Another example: English noun plural formation.
</P>
<PRE>
plural : Str -&gt; Str = \w -&gt; case w of {
_ + ("s" | "z" | "x" | "sh") =&gt; w + "es" ;
_ + ("a" | "o" | "u" | "e") + "y" =&gt; w + "s" ;
x + "y" =&gt; x + "ies" ;
_ =&gt; w + "s"
} ;
</PRE>
<P>
Semantics: variables are always bound to the <B>first match</B>, which is the first
in the sequence of binding lists <CODE>Match p v</CODE> defined as follows. In the definition,
<CODE>p</CODE> is a pattern and <CODE>v</CODE> is a value.
</P>
<PRE>
Match (p1|p2) v = Match p1 v ++ Match p2 v
Match (p1+p2) s = [Match p1 s1 ++ Match p2 s2 | i &lt;- [0..length s], (s1,s2) = splitAt i s]
Match p* s = Match "" s ++ Match p s ++ Match (p + p) s ++ ...
Match c v = [[]] if c == v -- for constant and literal patterns c
Match x v = [[(x,v)]] -- for variable patterns x
Match x@p v = [[(x,v)]] + M if M = Match p v /= []
Match p v = [] otherwise -- failure
</PRE>
<P>
Examples:
</P>
<UL>
<LI><CODE>x + "e" + y</CODE> matches <CODE>"peter"</CODE> with <CODE>x = "p", y = "ter"</CODE>
<LI><CODE>x@("foo"*)</CODE> matches any token with <CODE>x = ""</CODE>
<LI><CODE>x + y@("er"*)</CODE> matches <CODE>"burgerer"</CODE> with <CODE>x = "burg", y = "erer"</CODE>
</UL>
<A NAME="toc63"></A>
<H3>Prefix-dependent choices</H3> <H3>Prefix-dependent choices</H3>
<P> <P>
The construct exemplified in The construct exemplified in
@@ -2064,7 +2130,7 @@ This very example does not work in all situations: the prefix
} ; } ;
</PRE> </PRE>
<P></P> <P></P>
<A NAME="toc63"></A> <A NAME="toc64"></A>
<H3>Predefined types and operations</H3> <H3>Predefined types and operations</H3>
<P> <P>
GF has the following predefined categories in abstract syntax: GF has the following predefined categories in abstract syntax:
@@ -2087,11 +2153,11 @@ they can be used as arguments. For example:
-- e.g. (StreetAddress 10 "Downing Street") : Address -- e.g. (StreetAddress 10 "Downing Street") : Address
</PRE> </PRE>
<P></P> <P></P>
<A NAME="toc64"></A>
<H2>More features of the module system</H2>
<A NAME="toc65"></A> <A NAME="toc65"></A>
<H3>Interfaces, instances, and functors</H3> <H2>More features of the module system</H2>
<A NAME="toc66"></A> <A NAME="toc66"></A>
<H3>Interfaces, instances, and functors</H3>
<A NAME="toc67"></A>
<H3>Resource grammars and their reuse</H3> <H3>Resource grammars and their reuse</H3>
<P> <P>
A resource grammar is a grammar built on linguistic grounds, A resource grammar is a grammar built on linguistic grounds,
@@ -2144,19 +2210,19 @@ The rest of the modules (black) come from the resource.
<P> <P>
<IMG ALIGN="middle" SRC="Multi.png" BORDER="0" ALT=""> <IMG ALIGN="middle" SRC="Multi.png" BORDER="0" ALT="">
</P> </P>
<A NAME="toc67"></A>
<H3>Restricted inheritance and qualified opening</H3>
<A NAME="toc68"></A> <A NAME="toc68"></A>
<H2>More concepts of abstract syntax</H2> <H3>Restricted inheritance and qualified opening</H3>
<A NAME="toc69"></A> <A NAME="toc69"></A>
<H3>Dependent types</H3> <H2>More concepts of abstract syntax</H2>
<A NAME="toc70"></A> <A NAME="toc70"></A>
<H3>Higher-order abstract syntax</H3> <H3>Dependent types</H3>
<A NAME="toc71"></A> <A NAME="toc71"></A>
<H3>Semantic definitions</H3> <H3>Higher-order abstract syntax</H3>
<A NAME="toc72"></A> <A NAME="toc72"></A>
<H3>List categories</H3> <H3>Semantic definitions</H3>
<A NAME="toc73"></A> <A NAME="toc73"></A>
<H3>List categories</H3>
<A NAME="toc74"></A>
<H2>Transfer modules</H2> <H2>Transfer modules</H2>
<P> <P>
Transfer means noncompositional tree-transforming operations. Transfer means noncompositional tree-transforming operations.
@@ -2175,9 +2241,9 @@ See the
<A HREF="../transfer.html">transfer language documentation</A> <A HREF="../transfer.html">transfer language documentation</A>
for more information. for more information.
</P> </P>
<A NAME="toc74"></A>
<H2>Practical issues</H2>
<A NAME="toc75"></A> <A NAME="toc75"></A>
<H2>Practical issues</H2>
<A NAME="toc76"></A>
<H3>Lexers and unlexers</H3> <H3>Lexers and unlexers</H3>
<P> <P>
Lexers and unlexers can be chosen from Lexers and unlexers can be chosen from
@@ -2213,7 +2279,7 @@ Given by <CODE>help -lexer</CODE>, <CODE>help -unlexer</CODE>:
</PRE> </PRE>
<P></P> <P></P>
<A NAME="toc76"></A> <A NAME="toc77"></A>
<H3>Efficiency of grammars</H3> <H3>Efficiency of grammars</H3>
<P> <P>
Issues: Issues:
@@ -2224,7 +2290,7 @@ Issues:
<LI>parsing efficiency: <CODE>-mcfg</CODE> vs. others <LI>parsing efficiency: <CODE>-mcfg</CODE> vs. others
</UL> </UL>
<A NAME="toc77"></A> <A NAME="toc78"></A>
<H3>Speech input and output</H3> <H3>Speech input and output</H3>
<P> <P>
The<CODE>speak_aloud = sa</CODE> command sends a string to the speech The<CODE>speak_aloud = sa</CODE> command sends a string to the speech
@@ -2254,7 +2320,7 @@ The method words only for grammars of English.
Both Flite and ATK are freely available through the links Both Flite and ATK are freely available through the links
above, but they are not distributed together with GF. above, but they are not distributed together with GF.
</P> </P>
<A NAME="toc78"></A> <A NAME="toc79"></A>
<H3>Multilingual syntax editor</H3> <H3>Multilingual syntax editor</H3>
<P> <P>
The The
@@ -2271,12 +2337,12 @@ Here is a snapshot of the editor:
The grammars of the snapshot are from the The grammars of the snapshot are from the
<A HREF="http://www.cs.chalmers.se/~aarne/GF/examples/letter">Letter grammar package</A>. <A HREF="http://www.cs.chalmers.se/~aarne/GF/examples/letter">Letter grammar package</A>.
</P> </P>
<A NAME="toc79"></A> <A NAME="toc80"></A>
<H3>Interactive Development Environment (IDE)</H3> <H3>Interactive Development Environment (IDE)</H3>
<P> <P>
Forthcoming. Forthcoming.
</P> </P>
<A NAME="toc80"></A> <A NAME="toc81"></A>
<H3>Communicating with GF</H3> <H3>Communicating with GF</H3>
<P> <P>
Other processes can communicate with the GF command interpreter, Other processes can communicate with the GF command interpreter,
@@ -2293,7 +2359,7 @@ Thus the most silent way to invoke GF is
</PRE> </PRE>
</UL> </UL>
<A NAME="toc81"></A> <A NAME="toc82"></A>
<H3>Embedded grammars in Haskell, Java, and Prolog</H3> <H3>Embedded grammars in Haskell, Java, and Prolog</H3>
<P> <P>
GF grammars can be used as parts of programs written in the GF grammars can be used as parts of programs written in the
@@ -2305,15 +2371,15 @@ following languages. The links give more documentation.
<LI><A HREF="http://www.cs.chalmers.se/~peb/software.html">Prolog</A> <LI><A HREF="http://www.cs.chalmers.se/~peb/software.html">Prolog</A>
</UL> </UL>
<A NAME="toc82"></A> <A NAME="toc83"></A>
<H3>Alternative input and output grammar formats</H3> <H3>Alternative input and output grammar formats</H3>
<P> <P>
A summary is given in the following chart of GF grammar compiler phases: A summary is given in the following chart of GF grammar compiler phases:
<IMG ALIGN="middle" SRC="../gf-compiler.png" BORDER="0" ALT=""> <IMG ALIGN="middle" SRC="../gf-compiler.png" BORDER="0" ALT="">
</P> </P>
<A NAME="toc83"></A>
<H2>Case studies</H2>
<A NAME="toc84"></A> <A NAME="toc84"></A>
<H2>Case studies</H2>
<A NAME="toc85"></A>
<H3>Interfacing formal and natural languages</H3> <H3>Interfacing formal and natural languages</H3>
<P> <P>
<A HREF="http://www.cs.chalmers.se/~krijo/thesis/thesisA4.pdf">Formal and Informal Software Specifications</A>, <A HREF="http://www.cs.chalmers.se/~krijo/thesis/thesisA4.pdf">Formal and Informal Software Specifications</A>,

58
doc/tutorial/gf-tutorial2.txt
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@@ -1733,6 +1733,64 @@ possible to write, slightly surprisingly,
} }
``` ```
%--!
===Regular expression patterns===
(New since 7 January 2006.)
To define string operations computed at compile time, such
as in morphology, it is handy to use regular expression patterns:
- //p// ``+`` //q// : token consisting of //p// followed by //q//
- //p// ``*`` : token //p// repeated 0 or more times
(max the length of the string to be matched)
- ``-`` //p// : matches anything that //p// does not match
- //x// ``@`` //p// : bind to //x// what //p// matches
- //p// ``|`` //q// : matches what either //p// or //q// matches
The last three apply to all types of patterns, the first two only to token strings.
Example: plural formation in Swedish 2nd declension
(//pojke-pojkar, nyckel-nycklar, seger-segrar, bil-bilar//):
```
plural2 : Str -> Str = \w -> case w of {
pojk + "e" => pojk + "ar" ;
nyck + "e" + l@("l" | "r" | "n") => nyck + l + "ar" ;
bil => bil + "ar"
} ;
```
Another example: English noun plural formation.
```
plural : Str -> Str = \w -> case w of {
_ + ("s" | "z" | "x" | "sh") => w + "es" ;
_ + ("a" | "o" | "u" | "e") + "y" => w + "s" ;
x + "y" => x + "ies" ;
_ => w + "s"
} ;
```
Semantics: variables are always bound to the **first match**, which is the first
in the sequence of binding lists ``Match p v`` defined as follows. In the definition,
``p`` is a pattern and ``v`` is a value.
```
Match (p1|p2) v = Match p1 v ++ Match p2 v
Match (p1+p2) s = [Match p1 s1 ++ Match p2 s2 | i <- [0..length s], (s1,s2) = splitAt i s]
Match p* s = Match "" s ++ Match p s ++ Match (p + p) s ++ ...
Match c v = [[]] if c == v -- for constant and literal patterns c
Match x v = [[(x,v)]] -- for variable patterns x
Match x@p v = [[(x,v)]] + M if M = Match p v /= []
Match p v = [] otherwise -- failure
```
Examples:
- ``x + "e" + y`` matches ``"peter"`` with ``x = "p", y = "ter"``
- ``x@("foo"*)`` matches any token with ``x = ""``
- ``x + y@("er"*)`` matches ``"burgerer"`` with ``x = "burg", y = "erer"``
%--! %--!
===Prefix-dependent choices=== ===Prefix-dependent choices===