<chapter>
    <title>Basic Classes</title>

<sect1><title>Classes</title>
<toc depth=2></toc>


<sect2><title>Container Classes</title>
&docpp-HashTables-3;
&docpp-EST-IMatrix-3;
&docpp-EST-TMatrix-3;
&docpp-EST-FMatrix-3;
&docpp-EST-TList-3;
&docpp-EST-DVector-3;
&docpp-EST-FVector-3;
&docpp-EST-TSimpleVector-3;
&docpp-EST-TVector-3;
&docpp-EST-TrieNode-3;
&docpp-EST-TDeque-3;
&docpp-EST-TKVI-3;
&docpp-EST-TKVL-3;
&docpp-EST-TList-3;
&docpp-EST-TMatrix-3;
&docpp-EST-TSimpleVector-3;
&docpp-EST-StringTrie-3;
</sect2>
<sect2><title>String Classes</title>
&docpp-EST-String-3;
&docpp-EST-Token-3;
&docpp-EST-Regex-3;
</sect2>
<sect2><title>Support Classes</title>
&docpp-EST-TStructIterator-3;
&docpp-EST-TTI-Entry-3;
&docpp-EST-THandle-3;	
&docpp-EST-Handleable-3;
</sect2>
</sect1>

<sect1><title>Example Code</title>
<toc depth=2></toc>
&listexamplesection;
&matrixexamplesection;
&kvlexamplesection;
</sect1>
</chapter>

<!--
Local Variables:
mode: sgml
sgml-doctype:"speechtools.sgml"
sgml-parent-document:("speechtools.sgml" "chapter" "book")
sgml-omittag:nil
sgml-shorttag:t
sgml-minimize-attributes:nil
sgml-always-quote-attributes:t
sgml-indent-step:2
sgml-indent-data:t
sgml-exposed-tags:nil
sgml-local-catalogs:nil
sgml-local-ecat-files:nil
End:
-->

<![ IGNORE [
    <sect1>
	<title>Tlist C++ Class</title>

      <para>
	TList is a generic template doubly-linked list class. See
	<filename>include/EST_TList.h </filename>.
      </para>
	
      <para>
	The list is made up of a a series of "items" of class
	Titem. Each of these has a value, <function>val</function> and
	a next and previous pointer.  At present, the list uses a
	pointer to TBI to interate through the list class. The best
	way to iterate through the list is to use <tt>for</tt> loop
	style syntax.
      </para>

      &docpp-EST-TList-2;

      <sect2>
	<title>Instansiation of <function>EST_TList</function></title>


C++ does not have a standard for template instansiation which makes it
difficult to arbitrarily define new template types.   Within the 
speech_tools library new <function>EST_TList</function> template classes should be
defined as follows.  Suppose you have a class called <function>Thing</function>
and you wish to make a <function>EST_TList</function> of it.  Add to your file
the following
<screen>
#if defined(INSTANTIATE_TEMPLATES)
#include "../base_class/EST_TList.cc"
template class EST_TList<Thing>;
#endif
</screen>And add the name of that file to the <function>make</function> variable <function>TSRCS</function>
in your <filename>Makeilfe</function>

</sect2>

<sect2>
	<title>Future Changes</title>


We hope this class has become stable though some more member
functions may be added (e.g. <function>sort</function> etc.).

</sect2>
</sect1>

<sect1>
	<title>KVL C++ Class</title>


KVL (short for Key/Value List) is a template class of a list of
key/value pairs. There are two specifiable types for the KVL class,
the <emphasis>key</emphasis> and the <emphasis>value</emphasis>, e.g. <function>KVL<EST_String,EST_String></function>
produces a list of string pairs. KVL uses the TList class to actually
store its data.

<function>KVL</function> has much the same functionality as <function>EST_TList</function>, but
has some additional features which make use easier.  A crucial
difference between a <function>KVL</function> and a normal list is that each key
in the <function>KVL</function> is unique.

<filename>include/KVL.h</function>

</sect2>

<sect2>
	<title>Member functions of <function>KVL</function></title>


<itemizedlist bullet='@bullet'>

<listitem><para><function>val (K key)</function> This is the basic way of reading from the</para><para>
KVL. You give this function a key of type K and its returns a value.
<listitem><para><function>val (EST_TBI *p)</function> You can iterate through the <function>KVL</function></para><para>
in the same way as you do for TList. This function returns a value given
the iteration pointer.

<listitem><para><function>val_def (K key, V def)</function> Return "def" if "key" is not found.</para><para>

<listitem><para><function>key (EST_TBI *p)</function> </para><para>
returns the key for a given <function>EST_TBI</function> pointer.

<listitem><para><function>present (K k)</function> returns 1 if key "k" is in the </para><para>
<function>KVL</function>, 0 otherwise. Useful for seeing whether a key has been
defined.

<listitem><para><function>add_item (K k, V v, int ns).</function> </para><para>
Add KV pair k,v to <function>KVL</function>. By default, the list is serched
everytime for an occurance of k and if k is already defined, its value
is overwritten. However, if "ns" is set to 1, no searching of the list
is performed, and the key value pair is merely appended.

<listitem><para><function>change_item (K k, V v, int ns)</function> Overwrites existing value of</para><para>
k in <function>KVL</function> with v. If k isn't in the list, 

<listitem><para><function>change_item (EST_TBI *p, V v)</function> Overwrites existing value in </para><para>
<function>KVL</function>, accessed by pointer.

</itemizedlist>

In addition, the following overloaded operators are provided:
<itemizedlist bullet='@bullet'>
<listitem><para><function> = </function>. Makes a full copy of the <function>KVL</function> and all its members.</para><para>
<listitem><para><function> += </function>. Adds a KVL to the end of an existing <function>KVL</function>.</para><para>
<listitem><para><function> << </function>. Print list.</para><para>
</itemizedlist>

Examples of usage:
<screen>
KVL<int, int> x; // declare key value list.
EST_TBI *p;          // declare iteration pointer.

// read some values from standard input.
while(cin)
{
    cout << "type key then val\n";
    cin >> k;
    cin >> v;
    x.add_item(k, v);
}

// is vkey "9" in list?
cout << (x.present(9) ? "true" : "false") << endl;

for (p = x.list.head(); p != 0; p = next(p)) // iterate through list.
   cout << x.key(p) << " " << x.val(p); 
//print out all keys and values in list.
</screen>
</sect2>
</sect1>

<sect1>
	<title>Option  C++ Class</title>


The <emphasis>EST_Option</emphasis> class provides a uniform way to access options in
a program.  The most obvious source of options are from the command
line.  The function <function>parse_command_line2(...)</function> takes the C command
line variables (<function>argc</function>,<function>argv</function>) and produces an
<function>EST_Option</function> class.  Specifically it allows options names value
tpyes, defaults and documentation for opntions in a program.

The <function>EST_Options</function> class is derived from @code{KVL<EST_String,
EST_String>}, so all the <function>KVL</function> member functions also work with
<function>EST_Option</function>. It provides some useful extra functionality.

</sect2>

<sect2>
	<title>Member functions of <function>EST_Option</function></title>


All the options are stored as key value pairs of
<function>EST_String</function>s. However, it if often useful to have other types,
e.g. integers. This is possible, but it is the <function>EST_String</function> of the
integer that is actually stored. Additional member functions,
e.g. <function>add_item()</function> do the conversion automatically.

The member functions <function>ival(const EST_String &key)</function> will
return the value as an ineger and <function>fval(const EST_String &key)</function>
as a float.


<sect3>
	<title>File i/o</title>


It is sometimes convenient to store options in files, and the options
class supports a system where there is one.

There is one key/value pair per line. Lines can be commented by starting
them with the comment character (by default this is ";", but this can be
set using the <function>load()</function> function).  Each line must start with the
key. The remainder, which may appear as a list in the file, is taken as
the value.  Option files can be included in other option files by using
the <function>#include filename</function> directive.

If a particular key appears more than once when loading, the value of
the last occurance is used.  Files are loaded using the <function>load(...)</function>
function. The first argument to this is the file name, and the second
(optional) argument is the comment character. The load function merely
<emphasis>appends</emphasis> to the existing options (while overriding the values of
duplicate keys) - if an entirely new set of options are to be loadedcall
the <function>clear()</function> member function first.

The <function>EST_Option</function> class inherits the member functions of the
<function>KVL</function> class. In addition, the following exist:

<itemizedlist bullet='@bullet'>

<listitem><para><function>add_prefix(EST_String p)</function> Adds a prefix "p" to all keys in the</para><para>
list.  <listitem><para><function>remove_prefix(EST_String p)</function> removes a prefix "p" from all</para><para>
keys in the list.

<listitem><para><function>override_val(EST_String key, EST_String val).</function> If val is not empty, add</para><para>
keyval pair to option list.
<listitem><para><function>override_ival (EST_String key, int val)</function></para><para>
If val is not 0, add keyval pair to option list.
<listitem><para><function>override_fval (EST_String key, float val)</function></para><para>
If val is not 0.0, add keyval pair to option list.

<listitem><para><function>ival(EST_String rkey)</function></para><para>
return value of key, cast to an integer.
<listitem><para><function>fval(EST_String rkey)</function></para><para>
return value of key, cast to an float.
<listitem><para><function>dval(EST_String rkey)</function></para><para>
return value of key, cast to an double.
<listitem><para><function>add_iitem(EST_String key, int val)</function></para><para>
add integer value to list.
<listitem><para><function>add_fitem(EST_String key, float val)</function></para><para>
add float value to list.
</itemizedlist>

</sect3>
</sect2>
</sect1>

<sect1>
	<title>EST_TVector</title>


A simple vector class is provided for.  Member functions are 
given in <filename>include/EST_TVector.h</function>.

</sect3>
</sect2>
</sect1>

<sect1>
	<title>EST_TMatrix</title>


The <function>EST_TMatrix</function> class allows the creation of standard matrices.

See <filename>include/EST_TMatrix.h</function> for member functions.

There is a derive class <function>EST_FMatrix</function> for floats, the derivation
is used rather than a simple template to allow loading and saving to
files.

</sect3>
</sect2>
</sect1>

<sect1>
	<title>EST_Chunk</title>


The <function>EST_Chunk</function> classes offers a reference counting system
for arbitrary segments of memory.  This is primarily used by
the <function>EST_String</function> class.

</sect3>
</sect2>
</sect1>

<sect1>
	<title>EST_String</title>


This class was written for a number of reasons.  It offers a string
class functionally identical to the GNU libg++ String class.  We choose
to write our own string class rather than use the one provided with GNU
G++ for the following reasons.  The <function>String</function> class in libg++ is
different in different versions and causes lots of confusion when
compiling the system with different versions of <filename>libg++</function>.  If we
depended of the GNU <function>String</function> class we must provide <filename>libg++</function> on
all platforms we compile the system on.  This and the <function>Regex</function> class
are the only classes we relied on, by writing our one we all much
greater portability.  The GNU <function>String</function> class typcially copies
string values around while our replacement uses reference counts.
Because of the way we use strings in the speech tools and Festival
keeping track of reference counting allows a much more efficient
implementation of strings.  Thus our replacement string class is faster
for substantial benchmarks of Festival than the GNU equivalent.

The member functions of <function>EST_String</function> follow that of the GNU
<filename>libg++</function> <function>String</function> class as closely as possible (we designed it
for a drop in replacement of our current use of <function>String</function>).

</sect3>
</sect2>
</sect1>

<sect1>
	<title>EST_Regex</title>


As we wished to remove our dependence on GNU libg++ as described in the
previosu section we have provided a regular expression class which for
the most part follows that of the GNU libg++ Regex class.  This
implementation uses the regex functions from BSD4.4-lite (and earlier)
written by Henry Spencer.

</sect3>
</sect2>
</sect1>

<sect1>
	<title>EST_TNamedEnum</title>


A class which relates names (EST_String) to enums.

</sect3>
</sect2>
</sect1>

<sect1>
	<title>EST_StringTrie</title>


<function>EST_StringTrie</function> builds a tree index from string keys to arbiitrary
objects.  Thus objects may be index effciently from strings.  The
strings must be ascii (the eighth bit is ignored).

For example the following builds an index of regular expressions
based on their character form so that they need not be recompiled.
<screen>
EST_StringTrie regexes;

EST_Regex *make_regex(const char *r)
{
    // Access previously generated Regex or make new one
    // and add to index
    EST_Regex *rx;

    if ((rx = (EST_Regex *)regexes.lookup(r)) == 0)
    {
        EST_Regex *nr = new EST_Regex(r);
        regexes.add(r,(void *)nr);
        rx = nr;
    }

    return rx;
}
</screen>A StringTrie may be explicited clear with the function <function>clear()</function>.
The contents of the string tree make cleared by passing a
garabage collection function with <function>clear()</function> which will be
poassed each item in the trie as a <function>void *</function>.  The type
of the user provided garbage collection function is
<screen>
    void (*deletecontents)(void *n);
</screen>
</sect3>
</sect2>
</sect1>

<sect1>
	<title>EST_Token and EST_TokenStream</title>


<function>EST_Token</function> with <function>EST_TokenStream</function> provides a method for
reading files as whitespace separated tokens.  A token consists of four
parts, some of which may be empty: a name, the actual token, preceding
whitespace, preceding punctuation, the name and succeeding punctuation.
The definitions of whitespace and punctuation are user definable.  There
is also support for single character symbols and quoted tokens.

A token stream from which tokens may be gotten, may be a file or a
string.

For example the follow reads a file and output each toke on a new line
<screen>
   EST_TokenStream ts;
   EST_Token;

   ts.open("myfile");
   while (!ts.eof())
        cout << ts.get() << endl;
</screen>Although token streams support on symbol look ahead via <function>peek()</function>
they do support unget.

Punctuation (pre and post) may be set after opening a stream.  The
defaults are empty.  Any characters defined as punctuation found around
a token are striped and saved in the punctuation fields.  Single
character symbols will cause a token break when ever they occur
(i.e. separating whitespace is not required), again by default these are
empty.  Whitespace by default is defined as space, horizontal tab,
carriage return and line feed.

Quoting mode is off by default but may be started by calling
<function>set_quotes</function> with a quote character and an escape character
(typically <keysym>"</keysym> and <keysym>\</keysym>).  When in quote mode, a token starting
with the quote character will continue until next unescaped quote
character, including whitespace and punctuation.

Although a whole file's contents including all its whitespace may be
recorded by tokens from a token stream, any final whitespace after the
last real token may be mistakenly omitted unless care is taken.  In many
cases you'll just require the final whitespace before end of file to set
end of file which is the default.  In quotes mode <emphasis>all</emphasis> tokens
include this last token with an empty name will be returned before eof
is set.

    </sect1>
]]>


