Ruler-core Ruler-core is an attribute grammar preprocessor, with a number of extensions to deal with (inference)-rule based systems. How to get it to run: 1) checkout the repository or obtain the sources in another way 2) run cabal-install of ruler-core. This will install the dependencies, but will fail to build ruler-core itself. 3) run the cabal-files manually. The following is a trace: $ runghc Setup.hs configure --user Configuring ruler-core-0.9... $ runghc Setup.hs build Preprocessing executables for ruler-core-0.9... "processing: src/Ast.ag" "processing: src/Transform.ag" "processing: src/Errs.ag" Building ruler-core-0.9... [ 1 of 11] Compiling Env ( src/Env.hs, dist/build/ruler-core/ruler-core-tmp/Env.o ) [ 2 of 11] Compiling Pretty ( src/Pretty.hs, dist/build/ruler-core/ruler-core-tmp/Pretty.o ) [ 3 of 11] Compiling Common ( src/Common.hs, dist/build/ruler-core/ruler-core-tmp/Common.o ) [ 4 of 11] Compiling Ast ( dist/build/ruler-core/ruler-core-tmp/Ast.hs, dist/build/ruler-core/ruler-core-tmp/Ast.o ) [ 5 of 11] Compiling DepAnalysis ( src/DepAnalysis.hs, dist/build/ruler-core/ruler-core-tmp/DepAnalysis.o ) [ 6 of 11] Compiling Opts ( src/Opts.hs, dist/build/ruler-core/ruler-core-tmp/Opts.o ) [ 7 of 11] Compiling Errs ( dist/build/ruler-core/ruler-core-tmp/Errs.hs, dist/build/ruler-core/ruler-core-tmp/Errs.o ) [ 8 of 11] Compiling Transform ( dist/build/ruler-core/ruler-core-tmp/Transform.hs, dist/build/ruler-core/ruler-core-tmp/Transform.o ) [ 9 of 11] Compiling Parser ( src/Parser.hs, dist/build/ruler-core/ruler-core-tmp/Parser.o ) [10 of 11] Compiling Scanner ( dist/build/ruler-core/ruler-core-tmp/Scanner.hs, dist/build/ruler-core/ruler-core-tmp/Scanner.o ) [11 of 11] Compiling Main ( src/Main.hs, dist/build/ruler-core/ruler-core-tmp/Main.o ) Linking dist/build/ruler-core/ruler-core ... To see a list of command-line options: $ ./dist/build/ruler-core/ruler-core No AG source file specified. Usage: imp-visits