javaTeX -- a Java implementation of TeX

Timothy Murphy
<tim@maths.tcd.ie>

"What is this life, if full of care,
We have no time to stand and stare?"

		W.H. Davies ("Supertramp")

There are three ways of consuming javaTeX.
In increasing order of difficulty these are:

	(A) You can just run the classes in jtex.jar .

	(B) You can compile the Java files in jtex-java.tar.gz .

	(C) You can create the Java files from tex.web
	    with the material in jtex.tar.gz .

These options are described more fully below.

A. To run javaTeX

(1) Unpack jtex.jar ;

	jar xf jtex.jar

This will create a number of class files
in the subdirectory javaTeX ,
as well as a file "properties" in the current directory.

(2) Edit the file "properties"
to give the appropriate definition of TEXMF for your system.

(3) Run the command

	java javaTeX.texhash

This will create a file "tex.hash".

(This step is unnecessary
if you have a file TEXMF/ls-R,
as produced eg by web2c/teTeX ;
javaTeX can use this file in place of "tex.hash".)

(4) Create format files by

	java javaTeX.initex plain
	* \dump
	java javaTeX.initex latex.ltx

(5) Now you should be able to process the LaTeX file foo.tex by

	java javaTeX.latex foo

Notes:

i) All the javaTeX classes are in the "javaTeX" package,
and must therefore be placed in a subdirectory "javaTeX"
under the CLASSPATH, eg in the subdirectory javaTeX 
assuming '.' is in your CLASSPATH.

ii) You can have more than one TEXMF tree, eg

	TEXMF=/usr/local/lib/texmf:/common/TeX/texmf

(where ":" should be replaced on non-Unix systems
by the appropriate path.separator).

(iii) If you have created "tex.hash" you can move this
to the first directory on the TEXMF path if you prefer.
Or you can specify where it is in your properties file,
by a line like

	TEXHASH=/home/tim/Java/tex.hash

iv) You can move the file "properties" to
user.home/.javaTeX/properties or java.home/javaTeX.properties ,
if you prefer, where user.home is your home directory 
and java.home is the top of the Java library tree.

(v) Note that this is a 'small' TeX,
with each 'memoryword' taking up 4 bytes.
This means that mem_max is restricted to 64k.
This is sufficient to create latex.fmt
and to process reasonably straightforward LaTeX files.

(If you want to create a 'big' TeX,
with each 'memoryword' taking up 8 bytes,
you will find the necessary code in the sources,
as described in (C) below.
In effect the only change required is to
the definition of 'memoryword' in TeXLib.w .)

(vi) Although these notes are written from a Unix perspective,
javaTeX should work on other platforms.
(I have tried it very briefly under NT.)

(vii) Unpacking jtex.jar will also create 1-line Unix shell-scripts
"initex", "tex", "latex" and "texhash"
in the Unix subdirectory.
These are not required, but may be found useful.

As provided these scripts use the "tya" JIT Java compiler.
Simply remove the switch "-Djava.compiler=tya"
if you don't have, or don't want to use, TYA.

If you want to use these, transfer them to the current directory.
Then you can say eg

	./texhash
	./initex latex.ltx 
	./latex foo

(No doubt those living under Microsoft can substitute similar .bat files.)


B. To compile javaTeX

(1) The Java files for javaTeX can be unpacked by

	tar xzvf jtex-java.tar.gz .

(2) Create a subdirectory "javaTeX".

(3) There is some circularity in the Java code
(eg initex.java requires the memoryword class,
which in turn requires the twohalves class,
which is provided by initex.java).
This means that some files have to be compiled twice,
with warnings or errors on the first compilation.

The following commands (in this order) should suffice:

	jikes -d . TeXFile.java
	jikes -d . alpha*.java byte*.java word*.java
	jikes -d . memoryword.java	[expect errors]
	jikes -d . initex.java		[expect errors]
	jikes -d . initex.java
	jikes -d . memoryword.java
	jikes -d . virtex.java
	jikes -d . texhash.java

(4) Now proceed as in (A) above.

Note:

(i) I have used the IBM Java compiler "jikes"
which is available (free) for a number of platforms.
Change "jikes" to "javac" or "guavac" if you prefer.
(Doubtless any Java compiler will do.)


C. Creating the Java files

(1) The sources for javaTeX are in the three files
tex.jch, TeXLib.w and TeXFile.w .
To process these two tools are needed:
web2java and cweb+j .

If you untar jtex.tar.gz by

	tar xzvf jtex.tar.gz

all the requisite files will be created,
including two subdirectories "web2java" and "cweb".

(2) Go into the subdirectory "web2java" and say "make".
Hopefully this will create the executable "web2java".

(3) Go into the subdirectory "cweb".
This will contain the three files
{comm,ctang,cweav}-java.ch .
You will need the sources of the Knuth/Levy cweb-3.4 ,
as found in

	$CTAN/web/c_cpp/cweb/{*.w,*.c,*.h,*.tex,Makefile}

where eg CTAN=ftp://ftp.tex.ac.uk/tex-archive .

Assuming these sources are in the subdirectory web2c,
edit the Makefile to set

	CCHANGES=comm-java.ch
	TCHANGES=ctang-java.ch
	WCHANGES=cweav-java.ch

(or "mv Makefile.jtex Makefile").
Now say "make"; hopefully this will create 
"ctangle" and "cweave".

(4) Return to the main directory, and copy or create a link to tex.web , eg

	ln -s /src/teTeX/texk/web2c/tex.web .

[Substitute the location of tex.web on your system.]

(5) Say

	make jtex-src

This should make all the required Java files,
including initex.java and virtex.java .

(6) Now proceed as in (B), 
compiling the Java files and passing to (A).

Notes:

(i) The compilation as described above assumes the use of Unix,
with gcc, GNU make, bison and flex.
However, even if created under Unix.
the Java class files should in principle work on any system.

(ii) Change "jikes" to "javac" or "guavac" in the Makefile if you prefer.

(iii) If you want to create the documentation
TeXFile.tex and TeXLib.tex , say eg

	cweave +j TeXFile.w

You will need the cweb-LaTeX style files,
which can be found at 

	$CTAN/macros/latex/supported/cweb


D. Comments and suggestions

Any suggestions for speeding up javaTeX,
or indeed any other improvement,
will be gratefully received.
Please post them to me at tim@maths.tcd.ie .

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