*: initial thoughts

Signed-off-by: Vincent Batts <vbatts@hashbangbash.com>

mtree.go

@@ -0,0 +1,58 @@
+package mtree
+
+import "io"
+
+// Positioner responds with the newline delimited position
+type Positioner interface {
+	Pos() int
+}
+
+// DirectoryHierarchy is the mapped structure for an mtree directory hierarchy
+// spec
+type DirectoryHierarchy struct {
+	Comments []Comment
+	Entries  []Entry
+}
+
+// WriteTo simplifies the output of the resulting hierarchy spec
+func (dh DirectoryHierarchy) WriteTo(w io.Writer) (n int64, err error) {
+	return 0, nil
+}
+
+// Comment stores arbitrary metadata for the spec. Sometimes "user", "machine",
+// "tree", and "date". But most of the time, it includes the relative path of
+// the directory being stepped into. Or a "signature" like `#mtree v2.0`,
+type Comment struct {
+	Position int
+	Str      string
+	// TODO(vbatts) include a comment line parser
+}
+
+// Pos returns the line of this comment
+func (c Comment) Pos() int {
+	return c.Position
+}
+
+// Entry is each component of content in the mtree spec file
+type Entry struct {
+	Position int      // order in the spec
+	Name     string   // file or directory name
+	Keywords []string // TODO(vbatts) maybe a keyword typed set of values?
+	str      string   // raw string. needed?
+	Type     EntryType
+}
+
+// Pos returns the line of this comment
+func (e Entry) Pos() int {
+	return e.Position
+}
+
+type EntryType int
+
+const (
+	SpecialType   int = iota // line that has `/` prefix issue a "special" command (currently only /set and /unset)
+	FileType                 // indented line
+	DirectoryType            // ^ matched line, that is not /set
+	PathStepType             // .. - keywords/options are ignored
+	FullType                 // if the first word on the line has a `/` after the first character, it interpretted as a file pathname with options
+)