add custom Cmd and Dep types

command.go

@@ -0,0 +1,64 @@
+package task
+
+import (
+	"errors"
+	"strings"
+)
+
+type Params map[string]string
+
+type Cmd struct {
+	Cmd    string
+	Task   string
+	Params Params
+}
+
+type Dep struct {
+	Task   string
+	Params Params
+}
+
+var (
+	ErrCantUnmarshalCmd = errors.New("task: can't unmarshal cmd value")
+	ErrCantUnmarshalDep = errors.New("task: can't unmarshal dep value")
+)
+
+func (c *Cmd) UnmarshalYAML(unmarshal func(interface{}) error) error {
+	var cmd string
+	if err := unmarshal(&cmd); err == nil {
+		if strings.HasPrefix(cmd, "^") {
+			c.Task = strings.TrimPrefix(cmd, "^")
+		} else {
+			c.Cmd = cmd
+		}
+		return nil
+	}
+	var taskCall struct {
+		Task   string
+		Params Params
+	}
+	if err := unmarshal(&taskCall); err == nil {
+		c.Task = taskCall.Task
+		c.Params = taskCall.Params
+		return nil
+	}
+	return ErrCantUnmarshalCmd
+}
+
+func (d *Dep) UnmarshalYAML(unmarshal func(interface{}) error) error {
+	var task string
+	if err := unmarshal(&task); err == nil {
+		d.Task = task
+		return nil
+	}
+	var taskCall struct {
+		Task   string
+		Params Params
+	}
+	if err := unmarshal(&taskCall); err == nil {
+		d.Task = taskCall.Task
+		d.Params = taskCall.Params
+		return nil
+	}
+	return ErrCantUnmarshalDep
+}