added ':delete' builtin command (#121)

* added ':delete' command

* fixed doc

* fixed typo

* added dummy function for delete for windows

* detacted the functionality from the OS

* now deletion works based on selections

* added effective selection

* delete no longer sends 'send sync'

* fixed typo

* fixed typo

* added DOC to effective selection

* added DOC to deleteFiles()

* fixed DOC typos

* added ability to overwrite :delete

* added ability to overwrite :delete

complete.go

@@ -31,6 +31,7 @@ var (
 		"copy",
 		"cut",
 		"paste",
+		"delete",
 		"clear",
 		"draw",
 		"redraw",

doc.go

@@ -62,6 +62,7 @@ The following commands are provided by lf without default keybindings:
     select  changes current file selection to its argument
     source  reads the configuration file in its argument
     push    simulate key pushes given in its argument
+    delete  deletes the selected files. Warning: no prompt
 
 The following command line commands are provided by lf with default
 keybindings:

docstring.go

@@ -65,6 +65,7 @@ The following commands are provided by lf without default keybindings:
     select  changes current file selection to its argument
     source  reads the configuration file in its argument
     push    simulate key pushes given in its argument
+    delete  deletes the selected files. Warning: no prompt
 
 The following command line commands are provided by lf with default
 keybindings:

eval.go

@@ -582,6 +582,17 @@ func (e *callExpr) eval(app *app, args []string) {
 		if err := sendRemote("send sync"); err != nil {
 			app.ui.printf("paste: %s", err)
 		}
+	case "delete":
+		if cmd, ok := gOpts.cmds["delete"]; ok {
+			cmd.eval(app, e.args)
+		} else if err := app.nav.deleteFiles(); err != nil {
+			app.ui.printf("delete: %s", err)
+			return
+		}
+		app.nav.unselect()
+		if err := sendRemote("send load"); err != nil {
+			app.ui.printf("delete: %s", err)
+		}
 	case "clear":
 		if err := saveFiles(nil, false); err != nil {
 			app.ui.printf("clear: %s", err)

lf.1

@@ -74,6 +74,7 @@ The following commands are provided by lf without default keybindings:
     select  changes current file selection to its argument
     source  reads the configuration file in its argument
     push    simulate key pushes given in its argument
+    delete  deletes the selected files. Warning: no prompt
 .EE
 .PP
 The following command line commands are provided by lf with default keybindings:

nav.go

@@ -550,6 +550,22 @@ func (nav *nav) unselect() {
 	nav.selectionInd = 0
 }
 
+// effectiveSelection is a pure function that returns the selected files's paths.
+// In case the user has not selected a file it returns the file on the user's cursor.
+// If the function can't return a selection it returns an error.
+func (nav *nav) effectiveSelection() (list []string, err error) {
+	if len(nav.selections) == 0 {
+		curr, err := nav.currFile()
+		if err != nil {
+			return nil, errors.New("no file selected")
+		}
+
+		return []string{curr.path}, nil
+	}
+
+	return nav.currSelections(), nil
+}
+
 func (nav *nav) save(cp bool) error {
 	if len(nav.selections) == 0 {
 		curr, err := nav.currFile()
@@ -604,6 +620,24 @@ func (nav *nav) paste() error {
 	return nil
 }
 
+// deleteFiles deletes the user's selected files
+// it returns an error if no files are selected or if the OS fails to delete a file
+func (nav *nav) deleteFiles() error {
+	list, err := nav.effectiveSelection()
+
+	if err != nil {
+		return err
+	}
+
+	for _, path := range list {
+		if err := os.RemoveAll(path); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
 func (nav *nav) sync() error {
 	list, cp, err := loadFiles()
 	if err != nil {