Rename Tgt-related file

[goredo.git] / tgt.go

diff --git a/tgt.go b/tgt.go
new file mode 100644 (file)
index 0000000..e7f3359
--- /dev/null
+++ b/tgt.go
@@ -0,0 +1,76 @@
+package main
+
+import (
+       "path"
+       "path/filepath"
+)
+
+var TgtCache = make(map[string]*Tgt)
+
+func mustAbs(pth string) string {
+       pth, err := filepath.Abs(pth)
+       if err != nil {
+               panic(err)
+       }
+       return pth
+}
+
+func mustRel(basepath, targpath string) string {
+       pth, err := filepath.Rel(basepath, targpath)
+       if err != nil {
+               panic(err)
+       }
+       return pth
+}
+
+func cwdMustRel(paths ...string) string {
+       return mustRel(Cwd, path.Join(paths...))
+}
+
+func cwdAndTgt(tgt string) (string, string) {
+       cwd, tgt := path.Split(tgt)
+       return mustAbs(cwd), tgt
+}
+
+type Tgt struct {
+       // a/h/t resemble zsh'es :a, :h, :t modifiers
+       a   string // absolute path
+       h   string // head of the path, directory
+       t   string // tail of the path, only name
+       rel string // relative to Cwd
+       dep string // path to dependency file
+}
+
+func NewTgt(tgt string) *Tgt {
+       a := mustAbs(tgt)
+       if TgtCache != nil {
+               if t := TgtCache[a]; t != nil {
+                       return t
+               }
+       }
+       t := Tgt{a: a}
+       t.h, t.t = path.Split(t.a)
+       if len(t.h) > 1 {
+               t.h = t.h[:len(t.h)-1]
+       }
+       t.rel = mustRel(Cwd, t.a)
+       if TgtCache != nil {
+               TgtCache[a] = &t
+       }
+       return &t
+}
+
+func (tgt *Tgt) String() string {
+       return tgt.rel
+}
+
+func (tgt *Tgt) Dep() string {
+       if tgt.dep == "" {
+               tgt.dep = path.Join(tgt.h, RedoDir, tgt.t+DepSuffix)
+       }
+       return tgt.dep
+}
+
+func (tgt *Tgt) RelTo(cwd string) string {
+       return mustRel(cwd, tgt.a)
+}