programableにツリーを生成できるように公開関数追加

README.md

@@ -41,15 +41,18 @@ root
 
 ## Description
 ```
-├── CLI or Package.
-├── Given a markdown file or format, the result of Linux tree command is printed.
-├── `gtree` does not temporarily create directories or files.
-└── Create markdown file by referring to the file in the `testdata/` directory.
-    ├── Hierarchy is represented by indentation.
-    └── Indentation should be unified by one of the following.
-        ├── Tab
-        ├── Two half-width spaces（required: `-ts`）
-        └── Four half-width spaces（required: `-fs`）
+├── CLI and Package(1).
+│   ├── Given a markdown file or format, the result of the tree command is printed.
+│   ├── `gtree` does not temporarily create directories or files.
+│   └── Create markdown file by referring to the file in the `testdata/` directory.
+│       ├── Hierarchy is represented by indentation.
+│       └── Indentation should be unified by one of the following.
+│           ├── Tab
+│           ├── Two half-width spaces（required: `-ts`）
+│           └── Four half-width spaces（required: `-fs`）
+└── Package(2).
+    ├── You can also generate a tree programmatically.
+    └── Markdown is irrelevant.
 ```
 (generated by `cat testdata/sample0.md | gtree -fs`)
 
@@ -172,7 +175,7 @@ a
 ```
 ---
 
-## As Package
+## As Package 1 (like CLI)
 
 ### Installation
 ```sh
@@ -234,3 +237,69 @@ func main() {
 }
 
 ```
+
+## As Package 2 (generate a tree programmatically)
+
+### Installation
+```sh
+go get github.com/ddddddO/gtree
+```
+
+### Usage
+
+```go
+package main
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/ddddddO/gtree"
+)
+
+func main() {
+	root := gtree.NewRoot("root")
+	root.Add("child 1").Add("child 2").Add("child 3")
+	root.Add("child 4")
+	if err := gtree.ExecuteProgrammably(root, os.Stdout); err != nil {
+		panic(err)
+	}
+
+	// root
+	// ├── child 1
+	// │   └── child 2
+	// │       └── child 3
+	// └── child 4
+
+	fmt.Println("-----")
+
+	primate := gtree.NewRoot("Primate")
+
+	strepsirrhini := primate.Add("Strepsirrhini")
+	haplorrhini := primate.Add("Haplorrhini")
+
+	_ = strepsirrhini.Add("Lemuriformes")
+	_ = strepsirrhini.Add("Lorisiformes")
+
+	_ = haplorrhini.Add("Tarsiiformes")
+	_ = haplorrhini.Add("Simiiformes")
+	if err := gtree.ExecuteProgrammably(primate, os.Stdout); err != nil {
+		panic(err)
+	}
+
+	// root
+	// ├── child 1
+	// │   └── child 2
+	// │       └── child 3
+	// └── child 4
+	// -----
+	// Primate
+	// ├── Strepsirrhini
+	// │   ├── Lemuriformes
+	// │   └── Lorisiformes
+	// └── Haplorrhini
+	//     ├── Tarsiiformes
+	//     └── Simiiformes
+}
+
+```

example/main.go → example/like_cli/main.go

@@ -4,7 +4,7 @@ import (
 	"fmt"
 	"strings"
 
-	"github.com/ddddddO/gtree/example/adapter"
+	"github.com/ddddddO/gtree/example/like_cli/adapter"
 )
 
 func main() {

example/programable/main.go

@@ -0,0 +1,54 @@
+package main
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/ddddddO/gtree"
+)
+
+func main() {
+	root := gtree.NewRoot("root")
+	root.Add("child 1").Add("child 2").Add("child 3")
+	root.Add("child 4")
+	if err := gtree.ExecuteProgrammably(root, os.Stdout); err != nil {
+		panic(err)
+	}
+
+	// root
+	// ├── child 1
+	// │   └── child 2
+	// │       └── child 3
+	// └── child 4
+
+	fmt.Println("-----")
+
+	// https://ja.wikipedia.org/wiki/%E3%82%B5%E3%83%AB%E7%9B%AE
+	primate := gtree.NewRoot("Primate")
+
+	strepsirrhini := primate.Add("Strepsirrhini")
+	haplorrhini := primate.Add("Haplorrhini")
+
+	_ = strepsirrhini.Add("Lemuriformes")
+	_ = strepsirrhini.Add("Lorisiformes")
+
+	_ = haplorrhini.Add("Tarsiiformes")
+	_ = haplorrhini.Add("Simiiformes")
+	if err := gtree.ExecuteProgrammably(primate, os.Stdout); err != nil {
+		panic(err)
+	}
+
+	// root
+	// ├── child 1
+	// │   └── child 2
+	// │       └── child 3
+	// └── child 4
+	// -----
+	// Primate
+	// ├── Strepsirrhini
+	// │   ├── Lemuriformes
+	// │   └── Lorisiformes
+	// └── Haplorrhini
+	//     ├── Tarsiiformes
+	//     └── Simiiformes
+}

programable.go

@@ -0,0 +1,38 @@
+package gtree
+
+import "io"
+
+// TODO: 命名がイマイチ
+func ExecuteProgrammably(root *node, w io.Writer) error {
+	tree := &tree{
+		roots: []*node{root},
+		lastNodeFormat: lastNodeFormat{
+			directly:   "└──",
+			indirectly: "    ",
+		},
+		intermedialNodeFormat: intermedialNodeFormat{
+			directly:   "├──",
+			indirectly: "│   ",
+		},
+	}
+
+	tree.grow()
+	return tree.expand(w)
+}
+
+var programableNodeIdx int
+
+func NewRoot(name string) *node {
+	programableNodeIdx++
+
+	return newNode(name, rootHierarchyNum, programableNodeIdx)
+}
+
+func (current *node) Add(name string) *node {
+	programableNodeIdx++
+
+	n := newNode(name, current.hierarchy+1, programableNodeIdx)
+	n.parent = current
+	current.children = append(current.children, n)
+	return n
+}

testdata/sample0.md

@@ -1,10 +1,13 @@
 - ## Description
-    - CLI or Package.
-    - Given a markdown file or format, the result of the tree command is printed.
-    - `gtree` does not temporarily create directories or files.
-    - Create markdown file by referring to the file in the `testdata/` directory.
-        - Hierarchy is represented by indentation.
-        - Indentation should be unified by one of the following.
-            - Tab
-            - Two half-width spaces（required: `-ts`）
-            - Four half-width spaces（required: `-fs`）
+    - CLI and Package(1).
+        - Given a markdown file or format, the result of the tree command is printed.
+        - `gtree` does not temporarily create directories or files.
+        - Create markdown file by referring to the file in the `testdata/` directory.
+            - Hierarchy is represented by indentation.
+            - Indentation should be unified by one of the following.
+                - Tab
+                - Two half-width spaces（required: `-ts`）
+                - Four half-width spaces（required: `-fs`）
+    - Package(2).
+        - You can also generate a tree programmatically.
+        - Markdown is irrelevant.