fxp - The Functional XML Parser

Version 1.4.5, February 20, 2002

Andreas Neumann, University of Trier neumann@psi.uni-trier.de
Alexandru Berlea, University of Trier aberlea@psi.uni-trier.de

[Includes minor updates by Michael Norrish in 2018 to get this code to compile under mlton and Poly/ML.]

What is fxp?

fxp is a validating XML parser, written completely in the functional programming language SML. It has a (yet undocumented) programming interface allowing for production of XML applications based on fxp. It comes with some example applications:

fxp

The pure parser. It parses a document and finds well-formedness errors, validity errors and other problems;
fxcanon

Produces an equivalent canonical XML document. Canonical XML was invented by James Clark for testing XML parsers. It contains only the information a processor is required to pass to the application;
fxcopy

Reproduces the document parsed by fxp. The copy can be generated in a different encoding than the input, and can be normalized in different ways concerning, e.g., expansion of entity references;
fxesis

Produces an output similar to nsgmls's ESIS (Element Structure Information Set) output;
fxviz

An XML tree visualizer. It produces a graph description suitable as input to Georg Sander's vcg.

Installation

MLton

Using the mlton compiler, just change to the directory containing the desired executable, and type

mlton <appname>.mlb

For example, in src/Apps/Canon, type

mlton fxpcanon.mlb

and an fxpcanon executable will be created.

Poly/ML

With a recent Poly/ML installation, you should have access to the polyc command. Change to the relevant directory and compiler the poly-use.ML script, specifying the desired executable name on the command-line. For example, in src/Apps/Canon:

polyc -o fxpcanon poly-use.ML

SML/NJ Instructions (original)

In order to install fxp, you need an SML compiler. It has been tested with version 110.0.6 of SML of New Jersey, but it might also run with other versions. The compiler must have the compilation manager (CM) built in, which is the default when installing SML-NJ. We successfully compiled fxp on Linux with glibc2.1, Digital Unix 4.0 and Solaris 2.7. For other unices we expect no problems; compiling with the Windows version of SML-NJ has not been tried.

These are the steps for installing fxp under Unix:

Download the latest version of fxp;
Unpack the sources, and change to the fxp directory, e.g.:
```
 gunzip -c fxp-1.4.5.tar.gz | tar xf -
 cd fxp-1.4.5
```
Read the COPYRIGHT;
Edit the Makefile according to your needs. Probably you will only have to change the following:

INSTALL_PROGS is the list of programs to be installed. fxlib is only required if you want to develop applications with fxp.

FXP_BINDIR is where the executables are installed;

FXP_LIBDIR is where other files needed by fxp - the heap images and the library - are installed;

SML_BINDIR is the directory where the SML executables are found. It must contain the .arch-n-opsys script from the SML-NJ distribution, so make sure that this is where SML-NJ is physically installed;

SML_EXEC is the name of the SML executable. This is the program that is called for generating the heap image and at execution of fxp. If sml is in your PATH at installation time, you don't need the full path here.

SML_MAKEDEF is for defining the make command in SML. After version 110.0.3, SML-NJ changed the type of CM.make'. For earlier or working versions of SML-NJ, use the second or third variant of this definition.
Edit the file src/config.sml according to your needs. Currently only a single value can be configured here:
```
 val retrieveCommand : string
```
is the command to be used by fxp for retrieving a remote URI from the internet and storing it in a temporary file on the local file system. It is a string value and should contain the strings %1 and %2, where:
- %1 is replaced by the URI;
- %2 is replaced by the local filename.
It is recommended that the command exits with failure in case the URI cannot be retrieved. If the command generates an HTML error message instead (like, e.g., "lynx -source %1 > %2"), this HTML file is considered to be XML and will probably cause a mess of parsing errors. If you don't need URI retrieval, use "exit 1" which always fails on Unix. Sensible values are, e.g:
- "wget -qO %2 %1" (https://www.gnu.org/software/wget/)
Compile fxp by typing make;
Install fxp by typing make install.
If you want to use fxviz, you should also install vcg (ftp://ftp.cs.uni-sb.de/pub/graphics/vcg/).

If you experience problems installing fxp, send me mail at aberlea@psi.uni-trier.de

Check out for new versions at http://www.informatik.uni-trier.de/~aberlea/Fxp (old, now stale, link)

Alexandru Berlea.

mn200 / fxp145