fab

type Command struct {
	// Shell is the command to run,
	// as a single string with command name and arguments together.
	// It is parsed as if by a Unix shell,
	// with quoting and so on,
	// in order to produce the command name
	// and a list of individual argument strings.
	//
	// To bypass this parsing behavior,
	// you may specify Cmd and Args directly.
	Shell string

	// Cmd is the command to invoke,
	// either the path to a file,
	// or an executable file found in some directory
	// named in the PATH environment variable.
	//
	// Leave Cmd blank and specify Shell instead
	// to get shell-like parsing of a command and its arguments.
	Cmd string

	// Args is the list of command-line arguments
	// to pass to the command named in Cmd.
	Args []string

	// Dir is the directory in which to run the command.
	// The default is the value of GetDir(ctx) when the Run method is called.
	Dir string

	// Env is a list of VAR=VALUE strings to add to the environment when the command runs.
	Env []string

	// Verbose tells whether to connect the command's stdout and stderr
	// to this process's stdout and stderr.
	// If it's false,
	// the output is saved anyway in case the command fails.
	// If it does,
	// the returned error will be a CommandErr
	// containing the process's (combined) output.
	Verbose bool
	// contains filtered or unexported fields
}

type CommandErr struct {
	Err    error
	Output []byte
}

type FilesCommand struct {
	*Command
	In  []string
	Out []string
}

type HashDB interface {
	// Has tells whether the database contains the given entry.
	Has(context.Context, []byte) (bool, error)

	// Add adds an entry to the database.
	Add(context.Context, []byte) error
}

type HashTarget interface {
	Target
	Hash(context.Context) ([]byte, error)
}

type Runner struct {
	// contains filtered or unexported fields
}

type Target interface {
	// Run invokes the target's logic.
	//
	// Callers generally should not invoke a target's Run method.
	// Instead, pass the target to a Runner's Run method,
	// or to the global Run function.
	// That will handle concurrency properly
	// and make sure that the target is not rerun
	// when it doesn't need to be.
	Run(context.Context) error

	// ID is a unique ID for the target.
	ID() string
}