diff --git a/.gitignore b/.gitignore
index 1fcb152..f3e598a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,3 @@
out
+.idea
+.gradle
diff --git a/EinsteinsRiddle/EinsteinsRiddle.iml b/EinsteinsRiddle/EinsteinsRiddle.iml
index 1d1bbb2..35e74bb 100644
--- a/EinsteinsRiddle/EinsteinsRiddle.iml
+++ b/EinsteinsRiddle/EinsteinsRiddle.iml
@@ -125,6 +125,17 @@
+
+
+
+
+
+
+
+
+
+
+
diff --git a/EinsteinsRiddle/README.md b/EinsteinsRiddle/README.md
index cd023ca..5527d41 100644
--- a/EinsteinsRiddle/README.md
+++ b/EinsteinsRiddle/README.md
@@ -3,11 +3,21 @@ Einstein's Riddle
Solves a logic puzzle using the following approaches:
-* prolog directly
+* prolog directly (for comparative purposes)
* prolog underneath a Groovy DSL
-* a constraint solving library beneath a Groovy DSL
+* the __choco__ constraint solving library beneath a Groovy DSL
+* the __jacop__ constraint solving library beneath a Groovy DSL
+
+The interesting thing to note is that the "business rules" are the same in all cases. The "DSL helper code" would typically be hidden from the user.
The [prolog4j](https://github.com/espakm/prolog4j) generic prolog interface api is used along with the [tuprolog](http://tuprolog.alice.unibo.it/) prolog engine but
you can try some of the other engines supported by prolog4j if you wish.
-The [choco](http://www.emn.fr/z-info/choco-solver/) constraint solving library is used.
\ No newline at end of file
+The [choco](http://www.emn.fr/z-info/choco-solver/) and [JaCoP](http://jacop.osolpro.com/) constraint solving libraries are used.
+These libraries offer similar features as far as this problem is concerned. Given that the JaCoP package isn't available in a public
+Maven repository and has a restrictive GPL license, we have a preference for Choco for this example; but see the respective
+documentation of the two packages to see which better suits your needs.
+
+To install the library needed for JaCoP you will need to run the following command (windows command shown):
+
+ ..\gradlew downloadJaCoP
diff --git a/EinsteinsRiddle/build.gradle b/EinsteinsRiddle/build.gradle
new file mode 100644
index 0000000..2d1c9e9
--- /dev/null
+++ b/EinsteinsRiddle/build.gradle
@@ -0,0 +1,4 @@
+task downloadJaCoP() {
+ def name = 'JaCoP-3.1.2'
+ ant.get(src: "http://downloads.sourceforge.net/project/jacop-solver/$name/${name}.jar", dest: "lib")
+}
diff --git a/EinsteinsRiddle/src/jacop/JacopSolverDSL.groovy b/EinsteinsRiddle/src/jacop/JacopSolverDSL.groovy
new file mode 100644
index 0000000..c6c6d61
--- /dev/null
+++ b/EinsteinsRiddle/src/jacop/JacopSolverDSL.groovy
@@ -0,0 +1,181 @@
+package jacop
+
+import JaCoP.core.*
+import JaCoP.constraints.*
+import JaCoP.search.*
+import groovy.transform.Field
+
+enum Pet { dog, cat, bird, fish, horse }
+enum Color { green, white, red, blue, yellow }
+enum Sport { baseball, volleyball, football, hockey, tennis }
+enum Drink { water, tea, milk, coffee, beer }
+enum Nationality { Norwegian, Dane, Briton, German, Swede }
+
+import static Pet.*
+import static Color.*
+import static Sport.*
+import static Drink.*
+import static Nationality.*
+
+// define logic solver data structures
+num = 5
+center = 2
+first = 0
+println "Solving Einstein's Riddle:"
+
+@Field s = new Store()
+
+def makeEnumVar(String st, Object[] arr) { new IntVar(s, st, 0, arr.size()-1) }
+pets = new IntVar[num]
+colors = new IntVar[num]
+plays = new IntVar[num]
+drinks = new IntVar[num]
+nations = new IntVar[num]
+
+(0..
+ pets[i] = makeEnumVar("pet$i", pets)
+ colors[i] = makeEnumVar("color$i", colors)
+ plays[i] = makeEnumVar("plays$i", plays)
+ drinks[i] = makeEnumVar("drink$i", drinks)
+ nations[i] = makeEnumVar("nation$i", nations)
+}
+
+def pretty(enumClass, selected) { enumClass.values().find{ it.ordinal().toString() == selected.toString() } }
+
+// define DSL (simplistic non-refactored version)
+def neighbours(var1, val1, var2, val2) {
+ s.impose and(
+ ifOnlyIf(eq(var1[0], val1), eq(var2[1], val2)),
+ implies(eq(var1[1], val1), or(eq(var2[0], val2), eq(var2[2], val2))),
+ implies(eq(var1[2], val1), or(eq(var2[1], val2), eq(var2[3], val2))),
+ implies(eq(var1[3], val1), or(eq(var2[2], val2), eq(var2[4], val2))),
+ ifOnlyIf(eq(var1[4], val1), eq(var2[3], val2))
+ )
+}
+iff = { e1, c1, e2, c2 -> s.impose and(*(0.. s.impose eq(a, b) }
+
+dogs = dog; birds = bird; cats = cat; horses = horse
+a = owner = house = the = abode = person = man = to = is = side = next = who = different = 'ignored'
+
+// define the DSL in terms of DSL implementation
+def the(Nationality n) {
+ def ctx = [nations, n]
+ [
+ drinks:iff.curry(*ctx, drinks),
+ plays:iff.curry(*ctx, plays),
+ keeps:iff.curry(*ctx, pets),
+ rears:iff.curry(*ctx, pets),
+ owns:{ _the -> [first:{ house -> isEq(nations[first], n)}] },
+ has:{ _a ->
+ [pet:iff.curry(*ctx, pets)] + Color.values().collectEntries{ c ->
+ [c.toString(), { _dummy -> iff(*ctx, colors, c) } ]
+ }
+ },
+ lives: { _next -> [to: { _the ->
+ Color.values().collectEntries{ c ->
+ [c.toString(), { _dummy -> neighbours(*ctx, colors, c) } ]
+ }
+ }]}
+ ]
+}
+
+def the(Color c1) {[
+ house: { _is -> [on: { _the -> [left: { _side -> [of: { __the ->
+ Color.values().collectEntries{ c2 -> [c2.toString(), { _dummy ->
+ s.impose and(*(1..
+ Color.values().collectEntries{ c -> [c.toString(), { _house -> [
+ drinks:iff.curry(colors, c, drinks),
+ plays:iff.curry(colors, c, plays)
+ ] } ] }
+ },
+ known: { _to -> [
+ play: { sport ->
+ def ctx = [plays, sport]
+ [
+ rears: iff.curry(*ctx, pets),
+ keeps: iff.curry(*ctx, pets),
+ drinks: iff.curry(*ctx, drinks),
+ lives: { _next -> [to: { _the -> [one: { _who -> [
+ keeps: { pet -> neighbours(pets, pet, *ctx) },
+ drinks: { beverage -> neighbours(drinks, beverage, *ctx) }
+ ]}]}]}
+ ]
+ },
+ keep : { pet -> [
+ lives: { _next -> [to: { _the -> [man: { _who -> [
+ plays: { sport -> neighbours(pets, pet, plays, sport) }
+ ]}]}]}
+ ]}
+ ]},
+ from: { _the -> [center: { house ->
+ [drinks: { d -> isEq(drinks[center], d)}]
+ }]}
+]}
+
+def all(IntVar[] var) {
+ [are: { _different -> s.impose new Alldifferent(var) } ]
+}
+
+// define rules
+all pets are different
+all colors are different
+all plays are different
+all drinks are different
+all nations are different
+the man from the center house drinks milk
+the Norwegian owns the first house
+the Dane drinks tea
+the German plays hockey
+the Swede keeps dogs // alternate ending: has a pet dog
+the Briton has a red house // alternate ending: red abode
+the owner of the green house drinks coffee
+the owner of the yellow house plays baseball
+the person known to play football rears birds // alternate ending: keeps birds
+the man known to play tennis drinks beer
+the green house is on the left side of the white house
+the man known to play volleyball lives next to the one who keeps cats
+the man known to keep horses lives next to the man who plays baseball
+the man known to play volleyball lives next to the one who drinks water
+the Norwegian lives next to the blue house
+
+// invoke logic solver
+def vars = [pets, plays, drinks, colors, nations]
+def search = new DepthFirstSearch()
+def select = new SimpleMatrixSelect(vars as Var[][], new IndomainMin())
+search.solutionListener.searchAll(true)
+def result = search.labeling(s, select)
+println "Solutions found: " + result
+search.solutionListener.solutionsNo().times { i ->
+ println "Solution ${i + 1}:"
+ def sol = search.getSolution(i + 1)
+ def ps = sol.take(5); sol = sol.drop(5)
+ def ss = sol.take(5); sol = sol.drop(5)
+ def ds = sol.take(5); sol = sol.drop(5)
+ def cs = sol.take(5); sol = sol.drop(5)
+ def ns = sol.take(5)
+ 5.times {
+ printSol(ns[it], ps[it], ss[it], ds[it], cs[it])
+ }
+}
+
+def printSol(n, p, s, d, c) {
+ print 'The ' + pretty(Nationality, n)
+ print ' has a pet ' + pretty(Pet, p)
+ print ' plays ' + pretty(Sport, s)
+ print ' drinks ' + pretty(Drink, d)
+ println ' and lives in a ' + pretty(Color, c) + ' house'
+}
+
+def eq(IntVar x, IntVar y) { new XeqY(x, y) }
+def eq(IntVar x, enumVar) { new XeqC(x, enumVar.ordinal()) }
+def or(PrimitiveConstraint c1, PrimitiveConstraint c2) { new Or(c1, c2) }
+def and(PrimitiveConstraint[] cs) { new And(cs) }
+def ifOnlyIf(PrimitiveConstraint c1, PrimitiveConstraint c2) { new Eq(c1, c2) }
+def implies(PrimitiveConstraint c1, PrimitiveConstraint c2) { new IfThen(c1, c2) }
diff --git a/gradle/wrapper/gradle-wrapper.jar b/gradle/wrapper/gradle-wrapper.jar
new file mode 100644
index 0000000..8acea11
Binary files /dev/null and b/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
new file mode 100644
index 0000000..842a29d
--- /dev/null
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -0,0 +1,6 @@
+#Mon May 02 20:57:32 EST 2011
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
+distributionUrl=http\://gradle.artifactoryonline.com/gradle/distributions/gradle-0.9.2-bin.zip
diff --git a/gradlew b/gradlew
new file mode 100644
index 0000000..d8809f1
--- /dev/null
+++ b/gradlew
@@ -0,0 +1,168 @@
+#!/bin/bash
+
+##############################################################################
+## ##
+## Gradle wrapper script for UN*X ##
+## ##
+##############################################################################
+
+# Uncomment those lines to set JVM options. GRADLE_OPTS and JAVA_OPTS can be used together.
+# GRADLE_OPTS="$GRADLE_OPTS -Xmx512m"
+# JAVA_OPTS="$JAVA_OPTS -Xmx512m"
+
+GRADLE_APP_NAME=Gradle
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD="maximum"
+
+warn ( ) {
+ echo "$*"
+}
+
+die ( ) {
+ echo
+ echo "$*"
+ echo
+ exit 1
+}
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+case "`uname`" in
+ CYGWIN* )
+ cygwin=true
+ ;;
+ Darwin* )
+ darwin=true
+ ;;
+ MINGW* )
+ msys=true
+ ;;
+esac
+
+# Attempt to set JAVA_HOME if it's not already set.
+if [ -z "$JAVA_HOME" ] ; then
+ if $darwin ; then
+ [ -z "$JAVA_HOME" -a -d "/Library/Java/Home" ] && export JAVA_HOME="/Library/Java/Home"
+ [ -z "$JAVA_HOME" -a -d "/System/Library/Frameworks/JavaVM.framework/Home" ] && export JAVA_HOME="/System/Library/Frameworks/JavaVM.framework/Home"
+ else
+ javaExecutable="`which javac`"
+ [ -z "$javaExecutable" -o "`expr \"$javaExecutable\" : '\([^ ]*\)'`" = "no" ] && die "JAVA_HOME not set and cannot find javac to deduce location, please set JAVA_HOME."
+ # readlink(1) is not available as standard on Solaris 10.
+ readLink=`which readlink`
+ [ `expr "$readLink" : '\([^ ]*\)'` = "no" ] && die "JAVA_HOME not set and readlink not available, please set JAVA_HOME."
+ javaExecutable="`readlink -f \"$javaExecutable\"`"
+ javaHome="`dirname \"$javaExecutable\"`"
+ javaHome=`expr "$javaHome" : '\(.*\)/bin'`
+ export JAVA_HOME="$javaHome"
+ fi
+fi
+
+# For Cygwin, ensure paths are in UNIX format before anything is touched.
+if $cygwin ; then
+ [ -n "$JAVACMD" ] && JAVACMD=`cygpath --unix "$JAVACMD"`
+ [ -n "$JAVA_HOME" ] && JAVA_HOME=`cygpath --unix "$JAVA_HOME"`
+fi
+
+STARTER_MAIN_CLASS=org.gradle.wrapper.GradleWrapperMain
+CLASSPATH=`dirname "$0"`/gradle/wrapper/gradle-wrapper.jar
+WRAPPER_PROPERTIES=`dirname "$0"`/gradle/wrapper/gradle-wrapper.properties
+# Determine the Java command to use to start the JVM.
+if [ -z "$JAVACMD" ] ; then
+ if [ -n "$JAVA_HOME" ] ; then
+ if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+ # IBM's JDK on AIX uses strange locations for the executables
+ JAVACMD="$JAVA_HOME/jre/sh/java"
+ else
+ JAVACMD="$JAVA_HOME/bin/java"
+ fi
+ else
+ JAVACMD="java"
+ fi
+fi
+if [ ! -x "$JAVACMD" ] ; then
+ die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+if [ -z "$JAVA_HOME" ] ; then
+ warn "JAVA_HOME environment variable is not set"
+fi
+
+# Increase the maximum file descriptors if we can.
+if [ "$cygwin" = "false" -a "$darwin" = "false" ] ; then
+ MAX_FD_LIMIT=`ulimit -H -n`
+ if [ $? -eq 0 ] ; then
+ if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
+ MAX_FD="$MAX_FD_LIMIT"
+ fi
+ ulimit -n $MAX_FD
+ if [ $? -ne 0 ] ; then
+ warn "Could not set maximum file descriptor limit: $MAX_FD"
+ fi
+ else
+ warn "Could not query businessSystem maximum file descriptor limit: $MAX_FD_LIMIT"
+ fi
+fi
+
+# For Darwin, add GRADLE_APP_NAME to the JAVA_OPTS as -Xdock:name
+if $darwin; then
+ JAVA_OPTS="$JAVA_OPTS -Xdock:name=$GRADLE_APP_NAME"
+# we may also want to set -Xdock:image
+fi
+
+# For Cygwin, switch paths to Windows format before running java
+if $cygwin ; then
+ JAVA_HOME=`cygpath --path --mixed "$JAVA_HOME"`
+ CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
+
+ # We build the pattern for arguments to be converted via cygpath
+ ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
+ SEP=""
+ for dir in $ROOTDIRSRAW ; do
+ ROOTDIRS="$ROOTDIRS$SEP$dir"
+ SEP="|"
+ done
+ OURCYGPATTERN="(^($ROOTDIRS))"
+ # Add a user-defined pattern to the cygpath arguments
+ if [ "$GRADLE_CYGPATTERN" != "" ] ; then
+ OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
+ fi
+ # Now convert the arguments - kludge to limit ourselves to /bin/sh
+ i=0
+ for arg in "$@" ; do
+ CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
+ CHECK2=`echo "$arg"|egrep -c "^-"` ### Determine if an option
+
+ if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then ### Added a condition
+ eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
+ else
+ eval `echo args$i`="\"$arg\""
+ fi
+ i=$((i+1))
+ done
+ case $i in
+ (0) set -- ;;
+ (1) set -- "$args0" ;;
+ (2) set -- "$args0" "$args1" ;;
+ (3) set -- "$args0" "$args1" "$args2" ;;
+ (4) set -- "$args0" "$args1" "$args2" "$args3" ;;
+ (5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
+ (6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
+ (7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
+ (8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
+ (9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+ esac
+fi
+
+GRADLE_APP_BASE_NAME=`basename "$0"`
+
+exec "$JAVACMD" $JAVA_OPTS $GRADLE_OPTS \
+ -classpath "$CLASSPATH" \
+ -Dorg.gradle.appname="$GRADLE_APP_BASE_NAME" \
+ -Dorg.gradle.wrapper.properties="$WRAPPER_PROPERTIES" \
+ $STARTER_MAIN_CLASS \
+ "$@"
diff --git a/gradlew.bat b/gradlew.bat
new file mode 100644
index 0000000..479fddd
--- /dev/null
+++ b/gradlew.bat
@@ -0,0 +1,82 @@
+@if "%DEBUG%" == "" @echo off
+@rem ##########################################################################
+@rem ##
+@rem Gradle startup script for Windows ##
+@rem ##
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+@rem Uncomment those lines to set JVM options. GRADLE_OPTS and JAVA_OPTS can be used together.
+@rem set GRADLE_OPTS=%GRADLE_OPTS% -Xmx512m
+@rem set JAVA_OPTS=%JAVA_OPTS% -Xmx512m
+
+set DIRNAME=%~dp0
+if "%DIRNAME%" == "" set DIRNAME=.\
+
+@rem Find java.exe
+set JAVA_EXE=java.exe
+if not defined JAVA_HOME goto init
+
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto init
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+echo.
+goto end
+
+:init
+@rem Get command-line arguments, handling Windowz variants
+
+if not "%OS%" == "Windows_NT" goto win9xME_args
+if "%eval[2+2]" == "4" goto 4NT_args
+
+:win9xME_args
+@rem Slurp the command line arguments.
+set CMD_LINE_ARGS=
+set _SKIP=2
+
+:win9xME_args_slurp
+if "x%~1" == "x" goto execute
+
+set CMD_LINE_ARGS=%*
+goto execute
+
+:4NT_args
+@rem Get arguments from the 4NT Shell from JP Software
+set CMD_LINE_ARGS=%$
+
+:execute
+@rem Setup the command line
+
+set STARTER_MAIN_CLASS=org.gradle.wrapper.GradleWrapperMain
+set CLASSPATH=%DIRNAME%\gradle\wrapper\gradle-wrapper.jar
+set WRAPPER_PROPERTIES=%DIRNAME%\gradle\wrapper\gradle-wrapper.properties
+
+set GRADLE_OPTS=%JAVA_OPTS% %GRADLE_OPTS% -Dorg.gradle.wrapper.properties="%WRAPPER_PROPERTIES%"
+
+@rem Execute Gradle
+"%JAVA_EXE%" %GRADLE_OPTS% -classpath "%CLASSPATH%" %STARTER_MAIN_CLASS% %CMD_LINE_ARGS%
+
+:end
+@rem End local scope for the variables with windows NT shell
+if "%ERRORLEVEL%"=="0" goto mainEnd
+
+if not "%OS%"=="Windows_NT" echo 1 > nul | choice /n /c:1
+
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+if not "" == "%GRADLE_EXIT_CONSOLE%" exit "%ERRORLEVEL%"
+exit /b "%ERRORLEVEL%"
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega
\ No newline at end of file