NOTE: This is a fork of Logen. Please refer to the original repository.

Use a recent Ciao version and ciao get github.com/jfmc/logen to install this fork. Logen binary should be available in ~/.ciao/build/bin/logen. This version automatically points logen_dir to the logen source directory.

Changes in this fork:

• Packed as a Ciao bundle (see Manifest) (for this version, ignore build instructions in the rest of this document)
• Minor changes to fix compilation errors and warnings
• Enhanced comments mapping between logen and original predicates (see find_pattern.pl).

TODO:

• Fix testing (ciao test should run the tests in this bundle)
• Review code (e.g., use meta_predicate when needed, replace system by process_call), directory hierarchy, etc. (probably not worth here but in the original logen too)

LOGEN is an offline partial evaluation system for Prolog written using the so called "cogen approach". Basically, the cogen is a system which: based upon an annotated version of the program to be specialised produces a specialised partial evaluator for that program. This partial evaluator is called a generating extension the generating extension can be used to specialise the program in a very efficient manner.

Once downloaded you can test the installation with:

make cogen
make test

This should finish without errors.

To compile:

make

To specialise:

bin/logen PlFile "goal(A,B)"

You should also set the LOGEN_DIR (or LOGEN_HOME) environment variable to point to this directory (i.e., the one containing this README file). Alternatively, you can pass the --logen_dir D switch to logen.

For help:

bin/logen --help

Output gx files should be standalone ciao executables. So after specialising match.pl, match.pl.gx.cpx should be the executable.

./match.pl.gx.cpx --help
./match.pl.gx.cpx "match([a,a,b],R)"

Logen requires annotation files (ending with .ann) for every Prolog source file that has to be specialised. To generate annotation files you may want to use the binding-time analysis provided in another project: https://github.com/leuschel/logen-bta. You can use the -w switch for logen to supervise specialisation and provide better error feedback.

This system is based on research presented in

http://stups.hhu.de/w/Special:Publication/LeJoVaBr04_20 Michael Leuschel, Jesper Jørgensen, Wim Vanhoof, Maurice Bruynooghe Offline Specialisation in Prolog Using a Hand-Written Compiler Generator TPLP, 4(1-2): 139-191, 2004.

http://stups.hhu.de/w/Special:Publication/JoLe96_82 Jesper Jørgensen, Michael Leuschel Efficiently Generating Efficient Generating Extensions in Prolog In Dagstuhl Seminar on Partial Evaluation, volume 1110 of Lecture Notes in Computer Science, Springer-Verlag, 1996.

http://stups.hhu.de/w/Special:Publication/CrGaLeHe04_15 Stephen Craig, John Gallagher, Michael Leuschel, Kim S. Henriksen Fully Automatic Binding Time Analysis for Prolog [PDF] [Bibtex] [Old] [Upload] [Single Page] In LOPSTR, volume 3573 of Lecture Notes in Computer Science, Springer-Verlag, 2004.

http://stups.hhu.de/w/Special:Publication/LeElVaCrFo06_140 Michael Leuschel, Daniel Elphick, Mauricio Varea, Stephen Craig, Marc Fontaine The Ecce and Logen Partial Evaluators and their Web Interfaces In Proceedings PEPM 06, IBM Press, 2006.

The following articles discuss using Logen:

http://stups.hhu.de/w/Special:Publication/LeBr02_38 Michael Leuschel, Maurice Bruynooghe Logic program specialisation through partial deduction: Control Issues Theory and Practice of Logic Programming, 2(4-5): 461-515, 2002.

http://stups.hhu.de/w/Special:Publication/LeCrBrVa04_19 Michael Leuschel, Stephen Craig, Maurice Bruynooghe, Wim Vanhoof Specializing Interpreters using Offline Partial Deduction In Program Development in Computational Logic, volume 3049 of Lecture Notes in Computer Science, Springer-Verlag, 2004.

logen [Options] File.pl ["Atom."]
  Possible Options are:
  --help: Prints this message
  -w: watch mode (supervise specialization); equivalent to -wb -wu -wm -wc
  -W: watch mode; like -w option but halt at first alarm (-w -w1)
  -wb:   watch built-ins
  -wp:   watch for back-propagation of bindings onto non-declarative builtins
  -wc:   watch connectives (if,or) for back-propagation of bindings
  -wu:   watch out for infinite unfoldings
  -wm:   watch out for infinite memoisations
  -w1:   force halt at first watchdog alarm
  -c: run cogen only (not the .gx file)
  -s: run silently (do not display specialized program,...)
  --safe: run gx in safe sandbox mode
  -v: print debugging messages
  -vv: print more debugging messages
  -vvv: print even more debugging messages
  --compile_gx: compile the gx file using ciaoc
  -m: display memo table
  -np: no post-unfolding
  -ap: aggressive post-unfolding
  -g: display gx file
  --logen_dir ARG1: path to logen files
  -o ARG1: GX filename
  --spec_file ARG1: Spec filename
  --ciao_path ARG1: Ciao binary directory
  --simple_bta ARG1 ARG2 ARG3: Run simple bta: --simple_bta unfold/memo PLfile AnnFile
  -d: debug mode for GX file
  -d2: even more debugging messages in GX file
  --single_process: run cogen and gx in a single process - faster
  --xml: generate (some) diagnostic messages in xml