Clafer, the language
Clafer is a general-purpose lightweight structural modeling language developed by GSD Lab, University of Waterloo, and MODELS group at IT University of Copenhagen. Clafer can be used for modeling of static hierarchical structures but has no support for modeling the change of the structures over time (behavior). The main goal of Clafer is to make modeling more accessible to a wider range of users and domains.
There are many possible applications of Clafer; however, three are prominent:
Product-Line Architecture Modeling - aims at representing and managing commonality and variability of assets in product lines and creating and verifying product configurations. Clafer naturally supports multi-staged configuration.
Multi-Objective Product Optimization - aims at finding a set of products in a given product line that are optimal with respect to a set of objectives. Clafer multi-objective optimizer generates a Pareto front of optimal product configurations.
Domain Modeling - aims at improving the understanding of the problem domain in the early stages of software development and determining the requirements with fewer defects. This is also known as Concept Modeling or Ontology Modeling.
May applications actually combine the three. For example, see Technical Report: Case Studies on E/E Architectures for Power Window and Central Door Locks Systems.
Clafer, the compiler
Clafer compiler provides a reference implementation of Clafer, the language. It translates models in Clafer to other formats (e.g., Alloy, JSON, JS, HTML, DOT) to allow for reasoning and processing with existing tools (Alloy Analyzer, Choco3, and GraphViz).
Currently, the compiler is used by
- Web Frontends
- Michał Antkiewicz, Main developer.
- Kacper Bak, Original developer.
- Jimmy Liang, Developer.
- Luke Michael Brown, co-op student May-Aug 2013. Many improvements.
- Paulius Juodisius, customized BNFC generator and layout resolver.
- Rafael Olaechea, Multi-Objective Optimization extensions.
Getting the Clafer compiler
Clafer can be installed from a binary distribution (preferred), from Hackage, and from the source code.
Dependencies for running
Regardless of the installation method, the following are
- Java Platform (JDK) v8+, 64bit
- only needed for running Alloy validation
- 32bit on Windows
- only needed for Alloy output validation
- the program
dotis needed only in the
htmlmode for SVG graph generation
- the program
Installation from binaries
Binary distributions of the release 0.4.4 of Clafer Tools for Windows, Mac, and Linux, can be downloaded from Clafer Tools - Binary Distributions.
- Download the binaries and unpack
<target directory>of your choice.
- Add the
<target directory>to your system path so that the executables can be found.
Installation from Hackage
Stack is the only requirement: no other Haskell tooling needs to be installed because stack will automatically install everything that's needed.
- (first time only) Execute
- (first time only) Execute
stack install clafer.
- GHC >= 7.10.3 or 8.0.1 are recommended,
cabal-install>= 1.22, should be installed together with a GHC distribution,
- Install GHC
cabal install alex happy
cabal install clafer
- on Windows
- on Linux
- to automatically download Alloy jars, execute
alloy4.2.jarto the location of the clafer executable.
Installation from the source code
- it is installed automatically by
- update MSYS2 following the update procedure:
stack exec pacman -- -Sy
stack exec pacman -- --needed -S bash pacman pacman-mirrors msys2-runtime
- restart shell if the runtime was updated
stack exec pacman -- -Su
stack exec pacman -- -S make wget unzip diffutils
- it is installed automatically by
Important: branches must correspond
All related projects are following the simultaneous release model.
master contains releases, whereas the branch
develop contains code under development.
When building the tools, the branches should match.
Releases from branches 'master
are guaranteed to work well together.
Development versions from branchesdevelop` should work well together but this might not always be the case.
- in some
<source directory>of your choice, execute
git clone git://github.com/gsdlab/clafer.git
<source directory>/clafer, execute
stack setup. This will install all dependencies, build tools, and MSYS2 (on Windows).
cd <source directory>
stack exec makeon Windows
make install to=<target directory>on Linux/Mac
stack exec make install to=<target directory>on Windows
On Windows, use
makecommand instead of
make install to=/c/clafer-tools-0.4.4/
Integration with Sublime Text 2/3
Integration with VIM
(As printed by
Clafer 0.4.4 clafer [OPTIONS] [FILE] Common flags: -m --mode=CLAFERMODE Generated output type. Available CLAFERMODEs are: 'alloy' (default, Alloy 4.2); 'json' (intermediate representation of Clafer model); 'clafer' (analyzed and desugared clafer model); 'html' (original model in HTML); 'graph' (graphical representation written in DOT language); 'cvlgraph' (cvl notation representation written in DOT language); 'choco' (Choco constraint programming solver). Multiple modes can be specified at the same time, e.g., '-m alloy -m html'. -o --console-output Output code on console. -i --flatten-inheritance Flatten inheritance ('alloy' mode only). --timeout-analysis=INT Timeout for analysis. -l --no-layout Don't resolve off-side rule layout. -n --nl --new-layout Use new fast layout resolver (experimental). -c --check-duplicates Check duplicated clafer names in the entire model. -f --skip-resolver Skip name resolution. -k --keep-unused Keep uninstantated abstract clafers ('alloy' mode only). -s --no-stats Don't print statistics. -v --validate Validate outputs of all modes. Uses '<tooldir>/alloy4.2.jar' for Alloy models, '<tooldir>/chocosolver.jar' for Alloy models, and Clafer translator for desugared Clafer models. Use '--tooldir' to override the default location ('.') of these tools. --tooldir=DIR Specify the tools directory ('validate' only). Default: '.' (current directory). -a --alloy-mapping Generate mapping to Alloy source code ('alloy' mode only). --self-contained Generate a self-contained html document ('html' mode only). --add-graph Add a graph to the generated html model ('html' mode only). Requires the "dot" executable to be on the system path. --sr --show-references Whether the links for references should be rendered. ('html' and 'graph' modes only). --add-comments Include comments from the source file in the html output ('html' mode only). -e --ecore2clafer Translate an ECore model into Clafer. --ss=SCOPESTRATEGY --scope-strategy Use scope computation strategy: none or simple (default). --check-afm --afm Throws an error if the cardinality of any of the clafers is above 1. --meta-data Generate a 'fully qualified name'-'least-partially-qualified name'-'unique ID' map ('.cfr-map'). In Alloy and Choco modes, generate the scopes map ('.cfr-scope'). -? --help Display help message -V --version Print version information --numeric-version Print just the version number
The dependencies among the command line arguments are described on the model wiki.
Multiple modes can be used at the same time. For example,
clafer model.cfr -m alloy -m json -m html -m graph --self-contained --show-references --no-stats
-m alloy is only the default mode if no other modes are given. When other modes are given, the mode
-m alloy must be added explicitly if needed.
[OPTIONS] can also be specified directly in the model file by inserting the following compiler directive as the first line of the file:
//# --keep-unused -m=alloy
Options given at command line override the options given in the file using
//# which, in turn, override the defaults.
Using compiler directives
Compiler directives are comments of the form
//# <directive name>
The following directives are markers of locations in the input files for different purposes:
//# FRAGMENT- marks the beginning of the new module fragment.
//# GRAPH- marks the insertion point for a graph rendering. The graph is only produced in HTML mode with the argument
//# STATS- marks the insertion point for module statistics. The statistics can be omitted using the argument
//# SUMMARY- shorthand for
Here is some information about the development of the Clafer compiler.
We are following the simplified version of the successful Git branching model.
master is for releases and hot fixes only.
develop is for minor development and for integration of features from feature branches.
For any substantial work, branch off from
develop and create a pull request back into
develop after the work is completed.
We do testing and code review before merging into develop.
develop is ahead, merge it into the feature branch and perform integration testing there.
To make a release, we create a pull request from
master with version numbers after each release merge.
We have switched to Haskell Tool Stack. Install the tool first.
We have both automated tests and regression tests.
To run the automated tests (including both unit tests and doctests), execute
To only run unit tests, execute
stack test test-suite.
To only run doctests, execute
stack test doctests.
Note: it is still possible to run
cabal testas previously; however, the
For instructions for adding new modules to the doctest suite, see cabal integration.
To run all the automated tests and the regression tests, execute
We do test-driven development in the following way:
- create a test case Clafer model in either
test/negativedepending on whether a test case should compile successfully or return an error. For example, see a positive test case test/positive/redefinition.cfr.
- produce the intended compiler output automatically if possible and manually fix the output. Save the intended output as a regression test case. For example, see test/regression/redefinition.cfr.reg.
- implement the feature to reproduce the intended output: compiler the test case and execute
cd test make diffRegressions
this will show you how the current output diverges from the intended output.
Modifying the grammar
We are using a customized version of BNCF.
Clone the repository and install a binary of
bnfc so that it's visible in your
After changing the grammar, execute