Whoops, forgot to add the moved spec literal

spec/literal.go

@@ -0,0 +1,283 @@
+package spec
+
+import (
+	. "github.com/sdboyer/gogl"
+)
+
+// Define a graph literal fixture for testing here.
+// The literal has two edges and four vertices; one vertex is an isolate.
+//
+// bool state indicates whether using a transpose or not.
+type GraphLiteralFixture bool
+
+func (g GraphLiteralFixture) EachVertex(f VertexStep) {
+	vl := []Vertex{"foo", "bar", "baz", "isolate"}
+	for _, v := range vl {
+		if f(v) {
+			return
+		}
+	}
+}
+
+func (g GraphLiteralFixture) EachEdge(f EdgeStep) {
+	var el []Edge
+	if g {
+		el = []Edge{
+			NewEdge("foo", "bar"),
+			NewEdge("bar", "baz"),
+		}
+	} else {
+		el = []Edge{
+			NewEdge("bar", "foo"),
+			NewEdge("baz", "bar"),
+		}
+	}
+
+	for _, e := range el {
+		if f(e) {
+			return
+		}
+	}
+}
+
+func (g GraphLiteralFixture) EachEdgeIncidentTo(v Vertex, f EdgeStep) {
+	if g {
+		switch v {
+		case "foo":
+			f(NewEdge("foo", "bar"))
+		case "bar":
+			terminate := f(NewEdge("foo", "bar"))
+			if !terminate {
+				f(NewEdge("bar", "baz"))
+			}
+		case "baz":
+			f(NewEdge("bar", "baz"))
+		default:
+		}
+	} else {
+		switch v {
+		case "foo":
+			f(NewEdge("bar", "foo"))
+		case "bar":
+			terminate := f(NewEdge("bar", "foo"))
+			if !terminate {
+				f(NewEdge("baz", "bar"))
+			}
+		case "baz":
+			f(NewEdge("baz", "bar"))
+		default:
+		}
+	}
+}
+
+func (g GraphLiteralFixture) EachArcFrom(v Vertex, f EdgeStep) {
+	if g {
+		switch v {
+		case "foo":
+			f(NewEdge("foo", "bar"))
+		case "bar":
+			f(NewEdge("bar", "baz"))
+		default:
+		}
+	} else {
+		switch v {
+		case "bar":
+			f(NewEdge("bar", "foo"))
+		case "baz":
+			f(NewEdge("baz", "bar"))
+		default:
+		}
+	}
+}
+
+func (g GraphLiteralFixture) EachArcTo(v Vertex, f EdgeStep) {
+	if g {
+		switch v {
+		case "bar":
+			f(NewEdge("foo", "bar"))
+		case "baz":
+			f(NewEdge("bar", "baz"))
+		default:
+		}
+	} else {
+		switch v {
+		case "foo":
+			f(NewEdge("bar", "foo"))
+		case "bar":
+			f(NewEdge("baz", "bar"))
+		default:
+		}
+	}
+}
+
+func (g GraphLiteralFixture) EachPredecessorOf(v Vertex, f VertexStep) {
+	if g {
+		switch v {
+		case "bar":
+			f("foo")
+		case "baz":
+			f("bar")
+		default:
+		}
+	} else {
+		switch v {
+		case "foo":
+			f("bar")
+		case "bar":
+			f("baz")
+		default:
+		}
+	}
+}
+func (g GraphLiteralFixture) EachSuccessorOf(v Vertex, f VertexStep) {
+	if g {
+		switch v {
+		case "foo":
+			f("bar")
+		case "bar":
+			f("baz")
+		default:
+		}
+	} else {
+		switch v {
+		case "bar":
+			f("foo")
+		case "baz":
+			f("bar")
+		default:
+		}
+	}
+}
+
+func (g GraphLiteralFixture) EachAdjacentTo(v Vertex, f VertexStep) {
+	switch v {
+	case "foo":
+		f("bar")
+	case "bar":
+		terminate := f("foo")
+		if !terminate {
+			f("baz")
+		}
+	case "baz":
+		f("bar")
+	default:
+	}
+}
+
+func (g GraphLiteralFixture) HasVertex(v Vertex) bool {
+	switch v {
+	case "foo", "bar", "baz", "isolate":
+		return true
+	default:
+		return false
+	}
+}
+
+func (g GraphLiteralFixture) InDegreeOf(v Vertex) (degree int, exists bool) {
+	if g {
+		switch v {
+		case "foo":
+			return 0, true
+		case "bar":
+			return 1, true
+		case "baz":
+			return 1, true
+		case "isolate":
+			return 0, true
+		default:
+			return 0, false
+		}
+	} else {
+		switch v {
+		case "foo":
+			return 1, true
+		case "bar":
+			return 1, true
+		case "baz":
+			return 0, true
+		case "isolate":
+			return 0, true
+		default:
+			return 0, false
+		}
+	}
+}
+
+func (g GraphLiteralFixture) OutDegreeOf(v Vertex) (degree int, exists bool) {
+	if g {
+		switch v {
+		case "foo":
+			return 1, true
+		case "bar":
+			return 1, true
+		case "baz":
+			return 0, true
+		case "isolate":
+			return 0, true
+		default:
+			return 0, false
+		}
+
+	} else {
+		switch v {
+		case "foo":
+			return 0, true
+		case "bar":
+			return 1, true
+		case "baz":
+			return 1, true
+		case "isolate":
+			return 0, true
+		default:
+			return 0, false
+		}
+	}
+}
+
+func (g GraphLiteralFixture) DegreeOf(v Vertex) (degree int, exists bool) {
+	switch v {
+	case "foo":
+		return 1, true
+	case "bar":
+		return 2, true
+	case "baz":
+		return 1, true
+	case "isolate":
+		return 0, true
+	default:
+		return 0, false
+	}
+}
+
+func (g GraphLiteralFixture) HasEdge(e Edge) bool {
+	u, v := e.Both()
+
+	// TODO this is a little hinky until Arc is introduced
+	switch u {
+	case "foo":
+		return v == "bar"
+	case "bar":
+		return v == "baz" || v == "foo"
+	case "baz":
+		return v == "bar"
+	default:
+		return false
+	}
+}
+
+func (g GraphLiteralFixture) Density() float64 {
+	return 2 / 12 // 2 edges of maximum 12 in a 4-vertex digraph
+}
+
+func (g GraphLiteralFixture) Transpose() Digraph {
+	return GraphLiteralFixture(!g)
+}
+
+func (g GraphLiteralFixture) Size() int {
+	return 2
+}
+
+func (g GraphLiteralFixture) Order() int {
+	return 4
+}
+