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<div style="text-align: center;"><big><big><span
style="font-weight: bold;">TJC Package Manual<br>
</span></big></big><br>
<div style="text-align: left;">Usage:<br>
<div style="margin-left: 40px;"><span style="font-family: monospace;"><span
style="font-family: monospace;">package require TJC<br>
<br>
TJC::package package</span><br>
</span><span style="font-family: monospace;">TJC::command procname
classname<br>
</span><span style="font-family: monospace;"><span
style="font-family: monospace;">TJC::compile cmd</span><br>
</span><span style="font-family: monospace;"><br>
</span></div>
TJC is implemented as part of Jacl and includes runtime
support for TJC compiled procedures. The TJC package is loaded into
Jacl via the following Tcl command:<br>
<br>
<span style="font-family: monospace;">% package require TJC</span><br
style="font-family: monospace;">
<span style="font-family: monospace;">1.0</span><br
style="font-family: monospace;">
<br>
The <span style="font-family: monospace;">TJC</span> package defines
the <span style="font-family: monospace;">TJC</span> namespace and
adds three Tcl commands to the<span style="font-family: monospace;"> TJC</span>
namespace. The <span style="font-family: monospace;">TJC::package</span>
command is used to load a TJC compiled package into the Jacl
interpreter. Loading a TJC compiled package will source each of the Tcl
scripts included in the package and define each of the compiled Tcl
commands included in the package. In the following example, a TJC
compiled package named <span style="font-family: monospace;">foo.bar.baz</span>
is loaded.<br>
<br>
<span style="font-family: monospace;">% TJC::package foo.bar.baz</span><span
style="font-family: monospace;"></span><br>
<br>
A TJC package is initialized by loading a class named <span
style="font-family: monospace;">TJCExtension</span> from the named
package. This class implements the standard Extension API for Jacl
extensions, so one could also load a TJC package via the <span
style="font-family: monospace;">java::load</span> command as follows:<br>
<br>
<span style="font-family: monospace;">% java::load
foo.bar.baz.TJCExtension<br>
<br>
</span>The benefit of the <span style="font-family: monospace;">TJC::package</span>
command is that it is simpler and it can be used even when the <span
style="font-family: monospace;">java</span> package has not been
loaded into Jacl.<br>
<br>
The <span style="font-family: monospace;">TJC::command</span> Tcl
command is normally used only by the internal implementation of TJC.
End users will not need to invoke the this command. The command is used
to associate a Tcl command name with a compiled Java class file. When a
Tcl script is parsed, it is scanned for proc declaration that can be
compiled. The code for compiled proc declarations is then replaced with
a call to <span style="font-family: monospace;">TJC::command</span>.<br>
<br>
Original Tcl Script:<br>
<span style="font-family: monospace;"> set i 0</span><br
style="font-family: monospace;">
<span style="font-family: monospace;"> proc hello {}
{ return "Hello World" }</span><br style="font-family: monospace;">
<br>
Modified Tcl Script:<br>
<span style="font-family: monospace;"> set i 0</span><br
style="font-family: monospace;">
<span style="font-family: monospace;"> TJC::command
hello foo.bar.baz.HelloCmd</span><br style="font-family: monospace;">
<br>
At runtime, a <span style="font-family: monospace;">[TJC::package
foo.bar.baz]</span> command would cause the modified Tcl script to be
evaluated. The modified Tcl script would define the <span
style="font-family: monospace;">hello</span> command using the
compiled implementation in the Java class named <span
style="font-family: monospace;">HelloCmd</span>.<big><big><br>
<br>
</big></big>
<h3><a name="runtime"></a>Compiling Tcl procs at runtime<br>
</h3>
Support for compiling Tcl procedures at runtime is included as part of
the TJC package. Using <span style="font-family: monospace;">TJC::compile</span>,
one can compile a Tcl proc into Java source code and then into Java
byte code. The Java byte code implementation of the command will then
be loaded into the interpreter. Note that this runtime compilation is
not started by default and there is no means to automatically compile
all Tcl procs that are defined in the interpreter. The user needs to
explicitly indicate which procs should be compiled after the procs have
been defined. The most simple usage is the following.<br>
<br>
<span style="font-family: monospace;">package require TJC</span><br
style="font-family: monospace;">
<br style="font-family: monospace;">
<span style="font-family: monospace;">proc hello {} {</span><br
style="font-family: monospace;">
<span style="font-family: monospace;"> return "Hello
World"</span><br style="font-family: monospace;">
<span style="font-family: monospace;">}</span><br
style="font-family: monospace;">
<br style="font-family: monospace;">
<span style="font-family: monospace;">TJC::compile hello</span><br
style="font-family: monospace;">
<br>
The above invocation will start a second thread to do the compilation.
When the command has been compiled, the Tcl proc hello will be replaced
with a compiled version that performs the same operations as the Tcl
proc. Most users will only ever need to use the <span
style="font-family: monospace;">TJC::compile</span> command as shown
above.<br>
<br>
In the example above, the user has no way of knowing when the compile
job is finished. If the user needs to be informed when the compile job
is done, the <span style="font-family: monospace;">TJC::compile</span>
command supports notification via a callback or via a variable. The
following shows how a callback can be invoked when a compile job is
done.<br>
<br>
<span style="font-family: monospace;">package require TJC</span><br
style="font-family: monospace;">
<br style="font-family: monospace;">
<span style="font-family: monospace;">proc hello {} {</span><br
style="font-family: monospace;">
<span style="font-family: monospace;"> return "Hello
World"</span><br style="font-family: monospace;">
<span style="font-family: monospace;">}</span><br
style="font-family: monospace;">
<br style="font-family: monospace;">
<span style="font-family: monospace;">proc my_hello_ready { status cmd
msg } {</span><br style="font-family: monospace;">
<span style="font-family: monospace;"> if {$status ==
"OK"} {</span><br style="font-family: monospace;">
<span style="font-family: monospace;">
puts "command \"$cmd\" was compiled"</span><br
style="font-family: monospace;">
<span style="font-family: monospace;"> } else {</span><br
style="font-family: monospace;">
<span style="font-family: monospace;">
puts "command \"$cmd\" could not be compiled: $msg"</span><br
style="font-family: monospace;">
<span style="font-family: monospace;"> }</span><br
style="font-family: monospace;">
<span style="font-family: monospace;">}</span><br
style="font-family: monospace;">
<br style="font-family: monospace;">
<span style="font-family: monospace;">TJC::compile hello -readycmd
my_hello_ready</span><br style="font-family: monospace;">
<br style="font-family: monospace;">
<span style="font-family: monospace;">(after waiting a moment, the
following should be printed)</span><br style="font-family: monospace;">
<span style="font-family: monospace;">command "::hello" was compiled</span><br
style="font-family: monospace;">
<br>
In the example above, the callback is invoked with a status string that
can be "OK" or "ERROR". The cmd argument is the fully qualified name of
the compiled command. The msg argument is a string indicating a
compiler error if status is not "OK".<br>
<br>
In following example, notification is implemented with a variable. The
example sets a variable when the command has been compiled and
installed. The value that the ready variable is set to is the same as
the arguments to the <span style="font-family: monospace;">-readycmd</span>
command.<br>
<br style="font-family: monospace;">
<span style="font-family: monospace;">package require TJC</span><br
style="font-family: monospace;">
<br style="font-family: monospace;">
<span style="font-family: monospace;">proc hello {} {</span><br
style="font-family: monospace;">
<span style="font-family: monospace;"> return "Hello
World"</span><br style="font-family: monospace;">
<span style="font-family: monospace;">}</span><br
style="font-family: monospace;">
<span style="font-family: monospace;"></span><br
style="font-family: monospace;">
<span style="font-family: monospace;">TJC::compile hello -readyvar
my_hello_ready<br>
vwait my_hello_ready<br>
puts $my_hello_ready</span><br style="font-family: monospace;">
<span style="font-family: monospace;">(after a moment, the following
should be printed)<br>
OK ::hello {}</span><br>
<br>
<h3>Compiling Java classes at runtime</h3>
<span style="font-family: monospace;">TJC::command</span> can also be
used to compile source code for a Java class into byte code at runtime.
This functionality makes it easy to add dynamic generation of Java code
to an application. It can be extremely powerfull when used with the
java package. The following example shows how a static Java method can
be compiled and invoked.<br>
<br>
<span style="font-family: monospace;">package require TJC<br>
package require java<br style="font-family: monospace;">
</span><br style="font-family: monospace;">
<span style="font-family: monospace;">set jclass mytest.dynamic.Test1</span><br
style="font-family: monospace;">
<span style="font-family: monospace;">set jsrc {</span><br
style="font-family: monospace;">
<span style="font-family: monospace;">package mytest.dynamic;</span><br
style="font-family: monospace;">
<br style="font-family: monospace;">
<span style="font-family: monospace;">public class Test1 {</span><br
style="font-family: monospace;">
<span style="font-family: monospace;"> public static
String call() {</span><br style="font-family: monospace;">
<span style="font-family: monospace;">
return "CALLED";</span><br style="font-family: monospace;">
<span style="font-family: monospace;"> }</span><br
style="font-family: monospace;">
<span style="font-family: monospace;">}</span><br
style="font-family: monospace;">
<span style="font-family: monospace;">}</span><br
style="font-family: monospace;">
<br style="font-family: monospace;">
<span style="font-family: monospace;">set jinfo [list $jclass $jsrc]</span><br
style="font-family: monospace;">
<span style="font-family: monospace;">TJC::compile -java $jinfo
-readyvar my_class_ready</span><br style="font-family: monospace;">
<br style="font-family: monospace;">
<span style="font-family: monospace;">vwait my_class_ready<br>
puts $my_class_ready</span><br style="font-family: monospace;">
<span style="font-family: monospace;">
(after a moment, the following should be printed)<br>
OK mytest.dynamic.Test1 {}</span><br style="font-family: monospace;">
<br>
<span style="font-family: monospace;">(since the class has been loaded,
its methods can be invoked)</span><br style="font-family: monospace;">
<span style="font-family: monospace;">java::call <span
style="font-family: monospace;">mytest.dynamic.Test1 call</span><br
style="font-family: monospace;">
<span style="font-family: monospace;">CALLED</span><br
style="font-family: monospace;">
<br>
<br>
</span>Note that when <span style="font-family: monospace;">-java</span>
is passed to <span style="font-family: monospace;">TJC::command</span>,
either a <span style="font-family: monospace;">-readyvar</span> or <span
style="font-family: monospace;">-readycmd</span> argument pair must
also be passed. One or more classes generated from the Java class
declaration are loaded into the current class loader. Be aware that the
class loader can only load a given Java class once. Redefining or
unloading a class
is not supported. Also note that when a -readycmd or -readyvar
notification is done with a -java argument, the Java classes that were
loaded are passed in place of the cmd element.<br>
<big><br>
</big></div>
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distrib
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Mageia
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i586
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media
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core-release
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3728ff00d2930b6add4240a6383264ca
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