feat: initial version of pert simplifier

.circleci/config.yml

@@ -9,4 +9,7 @@ jobs:
     steps:
       - checkout
       - run: go mod download
+      - run: make install
       - run: make test
+      - run: curl -sfL https://install.goreleaser.com/github.com/golangci/golangci-lint.sh | sh -s v1.15.0
+      - run: PATH=$PATH:$(pwd)/bin make lint

.golangci.yml

@@ -0,0 +1,35 @@
+run:
+  deadline: 1m
+  tests: false
+  #skip-files:
+  #  - ".*\\.gen\\.go"
+
+linters-settings:
+  golint:
+    min-confidence: 0
+  maligned:
+    suggest-new: true
+  goconst:
+    min-len: 5
+    min-occurrences: 4
+  misspell:
+    locale: US
+
+linters:
+  disable-all: true
+  enable:
+    - vet
+    - goconst
+    - misspell
+    - deadcode
+    - misspell
+    - structcheck
+    - errcheck
+    - unused
+    - varcheck
+    - staticcheck
+    - unconvert
+    - gofmt
+    - goimports
+    - golint
+    - ineffassign

Makefile

@@ -6,3 +6,7 @@ test:
 .PHONY: install
 install:
 	cd cmd/pertify; go install
+
+.PHONY: lint
+lint:
+	golangci-lint run --verbose ./...

attr.go

@@ -27,7 +27,7 @@ func (a Attrs) IsEmpty() bool { return len(a) == 0 }
 
 func (a Attrs) String() string {
 	if a == nil {
-		return "[INVALID]"
+		return invalidPlaceholder
 	}
 	if len(a) == 0 {
 		return "[]"

cmd/pertify/go.sum

@@ -12,5 +12,6 @@ gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/urfave/cli.v2 v2.0.0-20180128182452-d3ae77c26ac8 h1:Ggy3mWN4l3PUFPfSG0YB3n5fVYggzysUmiUQ89SnX6Y=
 gopkg.in/urfave/cli.v2 v2.0.0-20180128182452-d3ae77c26ac8/go.mod h1:cKXr3E0k4aosgycml1b5z33BVV6hai1Kh7uDgFOkbcs=
+gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v3 v3.0.0-20190705120443-117fdf03f45f h1:nqBZgl3FUZD7Xe4yitNx/0mqkydzbl4Y89WSTjG6/ok=
 gopkg.in/yaml.v3 v3.0.0-20190705120443-117fdf03f45f/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

cmd/pertify/main.go

@@ -21,6 +21,7 @@ func main() {
 			&cli.BoolFlag{Name: "dot", Usage: "print 'dot' compatible output"},
 			&cli.BoolFlag{Name: "vertical", Usage: "displaying steps from top to bottom"},
 			&cli.BoolFlag{Name: "with-details", Usage: "Show pert numbers"},
+			&cli.BoolFlag{Name: "no-simplify", Usage: "Don't simplify the graph"},
 			&cli.BoolFlag{Name: "debug", Aliases: []string{"D"}, Usage: "verbose mode"},
 		},
 		Action: graph,
@@ -41,6 +42,9 @@ func graph(c *cli.Context) error {
 		return errors.Wrap(err, "failed to parse yaml file")
 	}
 
+	if c.Bool("no-simplify") {
+		config.Opts.NoSimplify = true
+	}
 	graph := graphman.FromPertConfig(config)
 	if c.Bool("debug") {
 		log.Println(graph)

graph.go

@@ -8,6 +8,8 @@ import (
 	"strings"
 )
 
+const invalidPlaceholder = "[INVALID]"
+
 type Graph struct {
 	vertices Vertices
 	edges    Edges
@@ -60,7 +62,7 @@ func (g Graph) ConnectedSubgraphs() Graphs {
 func (g Graph) ConnectedSubgraphFromVertex(start *Vertex) *Graph {
 	subgraph := New()
 	visitedEdges := map[*Edge]bool{}
-	start.WalkAdjacentVertices(func(current, previous *Vertex, depth int) error {
+	if err := start.WalkAdjacentVertices(func(current, previous *Vertex, depth int) error {
 		subgraph.vertices = append(subgraph.vertices, current)
 		for _, edge := range current.Edges() {
 			if visitedEdges[edge] {
@@ -70,7 +72,9 @@ func (g Graph) ConnectedSubgraphFromVertex(start *Vertex) *Graph {
 			subgraph.edges = append(subgraph.edges, edge)
 		}
 		return nil
-	})
+	}); err != nil {
+		log.Printf("error while walking vertices: %v", err)
+	}
 	return subgraph
 }
 
@@ -214,6 +218,16 @@ func (g *Graph) RemoveVertex(id string) bool {
 	return false
 }
 
+func (g *Graph) RemoveEdge(src, dst string) bool {
+	for k, v := range g.edges {
+		if v.src.id == src && v.dst.id == dst {
+			g.edges = append(g.edges[:k], g.edges[k+1:]...)
+			return true
+		}
+	}
+	return false
+}
+
 func (g Graph) GetVertex(id string) *Vertex {
 	for _, v := range g.vertices {
 		if v.id == id {
@@ -235,7 +249,7 @@ func (g *Graph) AddEdge(srcID, dstID string, attrs ...Attrs) *Edge {
 	dst := g.AddVertex(dstID)
 	edge := newEdge(src, dst, a)
 	src.successors = append(src.successors, edge)
-	dst.predecessors = append(src.predecessors, edge)
+	dst.predecessors = append(dst.predecessors, edge)
 	g.edges = append(g.edges, edge)
 	return edge
 }
@@ -253,7 +267,7 @@ func (g Graph) IsolatedVertices() Vertices {
 
 func (g *Graph) String() string {
 	if g == nil {
-		return "[INVALID]"
+		return invalidPlaceholder
 	}
 	elems := []string{}
 	for _, edge := range g.edges {

graph_test.go

@@ -2,7 +2,7 @@ package graphman
 
 import "fmt"
 
-func ExampleGraphConnectedSubgraphs() {
+func ExampleGraph_ConnectedSubgraphs() {
 	graph := New()
 	// component 1
 	graph.AddEdge("A", "B")
@@ -23,7 +23,7 @@ func ExampleGraphConnectedSubgraphs() {
 		fmt.Println(subgraph, subgraph.vertices)
 	}
 	// Output:
-	// {(A,B),(B,C),(C,D),(D,A)} {A,B,C,D}
+	// {(D,A),(A,B),(B,C),(C,D)} {A,B,C,D}
 	// {(E,E)} {E}
 	// {(F,G),(G,H),(G,I),(H,J),(I,J),(J,K)} {F,G,H,J,K,I}
 }
@@ -114,7 +114,7 @@ func ExampleGraph_components() {
 	// shortest: (Y,X,W,V,U) 4
 }
 
-func ExampleGraphFindAllPaths() {
+func ExampleGraph_FindAllPaths() {
 	graph := New()
 	graph.AddEdge("G", "H")
 	graph.AddEdge("A", "B")

path.go

@@ -13,7 +13,7 @@ type Path Edges
 
 func (p Path) String() string {
 	if p == nil {
-		return "[INVALID]"
+		return invalidPlaceholder
 	}
 	vertices := p.Vertices()
 	ids := []string{}
@@ -22,7 +22,7 @@ func (p Path) String() string {
 	}
 	ret := fmt.Sprintf("(%s)", strings.Join(ids, ","))
 	if !p.IsValid() {
-		ret += "[INVALID]"
+		ret += invalidPlaceholder
 	}
 	return ret
 }

pert_config.go

@@ -12,8 +12,18 @@ type PertAction struct {
 	DependsOn []string  `yaml:"depends_on"`
 }
 
+type PertState struct {
+	ID        string   `yaml:"id"`
+	Title     string   `yaml:"title"`
+	DependsOn []string `yaml:"depends_on"`
+}
+
 type PertConfig struct {
 	Actions []PertAction `yaml:"actions"`
+	States  []PertState  `yaml:"states"`
+	Opts    struct {
+		NoSimplify bool `yaml:"simplify"`
+	} `yaml:"opts"`
 }
 
 const (
@@ -27,6 +37,21 @@ func FromPertConfig(config PertConfig) *Graph {
 	graph.AddVertex(pertStartVertex)
 	graph.AddVertex(pertFinishVertex)
 
+	for _, state := range config.States {
+		attrs := Attrs{}
+		if state.Title != "" {
+			attrs.SetTitle(state.Title)
+		}
+		graph.AddVertex(state.ID, attrs)
+		for _, dependency := range state.DependsOn {
+			graph.AddEdge(
+				pertPostID(dependency),
+				state.ID,
+				Attrs{}.SetPertZeroTimeActivity(),
+			)
+		}
+	}
+
 	for _, action := range config.Actions {
 		attrs := Attrs{}
 		if action.Title != "" {
@@ -46,27 +71,30 @@ func FromPertConfig(config PertConfig) *Graph {
 		}
 
 		// relationships
-		postCurrent := fmt.Sprintf("post_%s", action.ID)
 		switch len(action.DependsOn) {
 		case 0: // no dependency, linking with Start
-			graph.AddEdge(pertStartVertex, postCurrent, attrs)
+			graph.AddEdge(
+				pertStartVertex,
+				pertPostID(action.ID),
+				attrs,
+			)
 		case 1: // only one dependency
 			dependency := action.DependsOn[0]
 			graph.AddEdge(
-				fmt.Sprintf("post_%s", dependency),
-				postCurrent,
+				pertPostID(dependency),
+				pertPreID(action.ID),
 				attrs,
 			)
 		default:
 			graph.AddEdge(
-				fmt.Sprintf("pre_%s", action.ID),
-				postCurrent,
+				pertPreID(action.ID),
+				pertPostID(action.ID),
 				attrs,
 			)
 			for _, dependency := range action.DependsOn {
 				graph.AddEdge(
-					fmt.Sprintf("post_%s", dependency),
-					fmt.Sprintf("pre_%s", action.ID),
+					pertPostID(dependency),
+					pertPreID(action.ID),
 					Attrs{}.SetPertZeroTimeActivity(),
 				)
 			}
@@ -75,28 +103,64 @@ func FromPertConfig(config PertConfig) *Graph {
 
 	// link ending vertices with finish
 	for _, vertex := range graph.SinkVertices() {
-		if vertex.ID() == pertFinishVertex {
+		if vertex.id == pertFinishVertex {
 			continue
 		}
 		graph.AddEdge(
-			vertex.ID(),
+			vertex.id,
 			pertFinishVertex,
 			Attrs{}.SetPertZeroTimeActivity(),
 		)
 	}
 
-	// optimize
-	// FIXME: TODO
-
 	// nice names
 	for _, vertex := range graph.Vertices() {
-		if vertex.ID() == pertStartVertex || vertex.ID() == pertFinishVertex {
+		if vertex.id == pertStartVertex || vertex.id == pertFinishVertex {
 			continue
 		}
 		if vertex.Attrs.GetTitle() == "" {
 			vertex.Attrs.SetPertUntitledState()
 		}
 	}
 
+	for _, vertex := range graph.Vertices() {
+		if vertex.Attrs.GetTitle() == "" {
+			vertex.Attrs.SetTitle(vertex.id)
+		}
+	}
+	if !config.Opts.NoSimplify { // simplify the graph
+		verticesToDelete := map[string]bool{} // creating a map so we can iterate over vertices while deleting some entries
+		for _, vertex := range graph.Vertices() {
+			if pertIsUntitledState(vertex) || true {
+				if vertex.OutDegree() == 1 { // remove dummy states with only one dummy successor
+					successor := vertex.SuccessorEdges()[0]
+					if pertIsZeroTimeActivity(successor) {
+						for _, predecessor := range vertex.PredecessorEdges() {
+							predecessor.dst = successor.dst
+						}
+						graph.RemoveEdge(vertex.id, successor.dst.id)
+						verticesToDelete[vertex.id] = true
+					}
+				}
+			}
+		}
+		for id := range verticesToDelete {
+			graph.RemoveVertex(id)
+		}
+	}
+
 	return graph
 }
+
+func pertPreID(id string) string  { return fmt.Sprintf("pre_%s", id) }
+func pertPostID(id string) string { return fmt.Sprintf("post_%s", id) }
+
+func pertIsZeroTimeActivity(edge *Edge) bool {
+	pert := edge.GetPert()
+	return pert != nil && pert.IsZeroTimeActivity
+}
+
+func pertIsUntitledState(vertex *Vertex) bool {
+	pert := vertex.GetPert()
+	return pert != nil && pert.IsUntitledState
+}

pert_config_test.go

@@ -55,5 +55,5 @@ actions:
 	graph := FromPertConfig(config)
 	fmt.Println(graph)
 	// Output:
-	// {(Start,post_1)[[pert:To=4,Tm=6,Tp=10,Te=6.33,σe=1,Ve=1,title:Prepare foundation]],(Start,post_2)[[pert:To=2,Tm=4,Tp=7,Te=4.17,σe=0.83,Ve=0.69,title:Make & position door frames]],(Start,post_3)[[pert:To=7,Tm=9,Tp=12,Te=9.17,σe=0.83,Ve=0.69,title:Lay drains & floor base]],(post_5,post_4)[[pert:To=2,Tm=4,Tp=5,Te=3.83,σe=0.5,Ve=0.25,title:Install service & settings]],(pre_5,post_5)[[pert:To=7,Tm=10,Tp=15,Te=10.33,σe=1.33,Ve=1.78,title:Erect walls]],(post_1,pre_5)[[pert:]],(post_2,pre_5)[[pert:]],(pre_6,post_6)[[pert:To=1,Tm=2,Tp=4,Te=2.17,σe=0.5,Ve=0.25,title:Plaster ceilings]],(post_4,pre_6)[[pert:]],(post_7,pre_6)[[pert:]],(post_5,post_7)[[pert:To=4,Tm=6,Tp=8,Te=6,σe=0.67,Ve=0.44,title:Erect roof]],(post_7,post_8)[[pert:To=7,Tm=9,Tp=11,Te=9,σe=0.67,Ve=0.44,title:Install door & windows]],(pre_9,post_9)[[pert:To=1,Tm=2,Tp=3,Te=2,σe=0.33,Ve=0.11,title:Fit gutters & pipes]],(post_3,pre_9)[[pert:]],(post_6,pre_9)[[pert:]],(pre_10,post_10)[[pert:To=1,Tm=2,Tp=3,Te=2,σe=0.33,Ve=0.11,title:Paint outside]],(post_8,pre_10)[[pert:]],(post_9,pre_10)[[pert:]],(post_10,Finish)[[pert:]]}
+	// {(Start,pre_5)[[pert:To=4,Tm=6,Tp=10,Te=6.33,σe=1,Ve=1,title:Prepare foundation]],(Start,pre_5)[[pert:To=2,Tm=4,Tp=7,Te=4.17,σe=0.83,Ve=0.69,title:Make & position door frames]],(Start,pre_9)[[pert:To=7,Tm=9,Tp=12,Te=9.17,σe=0.83,Ve=0.69,title:Lay drains & floor base]],(post_5,Finish)[[pert:To=2,Tm=4,Tp=5,Te=3.83,σe=0.5,Ve=0.25,title:Install service & settings]],(pre_5,post_5)[[pert:To=7,Tm=10,Tp=15,Te=10.33,σe=1.33,Ve=1.78,title:Erect walls]],(pre_6,pre_9)[[pert:To=1,Tm=2,Tp=4,Te=2.17,σe=0.5,Ve=0.25,title:Plaster ceilings]],(post_7,pre_6)[[pert:]],(post_5,Finish)[[pert:To=4,Tm=6,Tp=8,Te=6,σe=0.67,Ve=0.44,title:Erect roof]],(post_7,Finish)[[pert:To=7,Tm=9,Tp=11,Te=9,σe=0.67,Ve=0.44,title:Install door & windows]],(pre_9,pre_10)[[pert:To=1,Tm=2,Tp=3,Te=2,σe=0.33,Ve=0.11,title:Fit gutters & pipes]],(pre_10,Finish)[[pert:To=1,Tm=2,Tp=3,Te=2,σe=0.33,Ve=0.11,title:Paint outside]]}
 }

vertex_test.go

@@ -66,19 +66,19 @@ func ExampleVertex_helpers() {
 	// bob
 	//   isolated:              false
 	//   neighbors:             {bob,eve,sam}
-	//   predecessor vertices:  {sam}
-	//   predecessor edges:     {(sam,bob)}
+	//   predecessor vertices:  {bob,sam}
+	//   predecessor edges:     {(bob,bob),(sam,bob)}
 	//   successor vertices:    {bob,eve}
 	//   successor edges:       {(bob,eve),(bob,bob)}
-	//   edges:                 {(sam,bob),(bob,eve),(bob,bob)}
+	//   edges:                 {(bob,bob),(sam,bob),(bob,eve),(bob,bob)}
 	// eve
 	//   isolated:              false
-	//   neighbors:             {bob,eve,joy}
-	//   predecessor vertices:  {bob,eve,joy}
-	//   predecessor edges:     {(bob,eve),(eve,joy),(joy,eve)}
+	//   neighbors:             {bob,joy}
+	//   predecessor vertices:  {bob,joy}
+	//   predecessor edges:     {(bob,eve),(joy,eve)}
 	//   successor vertices:    {joy}
 	//   successor edges:       {(eve,joy)}
-	//   edges:                 {(bob,eve),(eve,joy),(joy,eve),(eve,joy)}
+	//   edges:                 {(bob,eve),(joy,eve),(eve,joy)}
 	// han
 	//   isolated:              true
 	//   neighbors:             {}
@@ -89,12 +89,12 @@ func ExampleVertex_helpers() {
 	//   edges:                 {}
 	// joy
 	//   isolated:              false
-	//   neighbors:             {bob,eve}
-	//   predecessor vertices:  {bob,eve}
-	//   predecessor edges:     {(bob,eve),(eve,joy)}
+	//   neighbors:             {eve}
+	//   predecessor vertices:  {eve}
+	//   predecessor edges:     {(eve,joy)}
 	//   successor vertices:    {eve}
 	//   successor edges:       {(joy,eve)}
-	//   edges:                 {(bob,eve),(eve,joy),(joy,eve)}
+	//   edges:                 {(eve,joy),(joy,eve)}
 	// sam
 	//   isolated:              false
 	//   neighbors:             {bob}