Website: http://people.csail.mit.edu/aleks/squander/
- unified execution of imperative and declarative code
- executable Alloy-like specifications for Java programs
- first order relational logic with transitive closure
- support for Java arrays and collections
- easy to specify and solve constraint problems
class Graph {
class Node {
public final int label;
public Node(int label) { this.label = label; }
}
class Edge {
public final Node src, dest;
public final int cost;
public Edge(Node src, Node dest, int cost) { this.src = src; this.dest = dest; this.cost = cost; }
}
private Set<Node> nodes = new LinkedHashSet<Node>();
private Set<Edge> edges = new LinkedHashSet<Edge>();
/*
* Graph k-Coloring problem: assign up to k different colors to graph nodes
* such that no two adjacent nodes have the same color.
*/
@Ensures({
"return.keys = this.nodes.elts",
"all c : return.vals | c > 0 && c <= k",
"all e : this.edges.elts | return.elts[e.src] != return.elts[e.dst]"
})
@Modifies("return.elts")
@Options(ensureAllInts=true)
@FreshObjects(cls = Map.class, typeParams={Node.class, Integer.class}, num = 1)
public Map<Node, Integer> color(int k) {
return Squander.exe(this, k);
}
public static void main(String[] args) {
Graph g = readGraph(args[0]); // reads graph from file
int k = Integer.parseInt(args[1]);
Map<Node, Integer> colors = g.color(k);
System.out.println(colors);
}
}git clone https://github.com/aleksandarmilicevic/squander.git
cd squander
# -- initialize ANT to use Eclipse compiler (*needs to be done only once*) --
export ECLIPSE_HOME="<your-eclipse-home>"
ant init-eclipse-compiler # might require sudo, if your ANT is installed e.g., in /usr/share
# ---------------------------------------------------------------------------
ant build-eclipse-compiler
ant test # runs all unit tests
and jar # creates dist/squander.jar