Add rmtrailingws feature

cmd/micro/buffer.go

@@ -9,6 +9,7 @@ import (
 	"os/exec"
 	"os/signal"
 	"path/filepath"
+	"regexp"
 	"strconv"
 	"strings"
 	"time"
@@ -283,6 +284,18 @@ func (b *Buffer) SaveAs(filename string) error {
 	b.UpdateRules()
 	dir, _ := homedir.Dir()
 	b.Path = strings.Replace(filename, "~", dir, 1)
+	if b.Settings["rmtrailingws"].(bool) {
+		r, _ := regexp.Compile(`[ \t]+$`)
+		for lineNum, line := range b.Lines(0, b.NumLines) {
+			indices := r.FindStringIndex(line)
+			if indices == nil {
+				continue
+			}
+			startLoc := Loc{indices[0], lineNum}
+			b.deleteToEnd(startLoc)
+		}
+		b.Cursor.Relocate()
+	}
 	if b.Settings["eofnewline"].(bool) {
 		end := b.End()
 		if b.RuneAt(Loc{end.X - 1, end.Y}) != '\n' {
@@ -362,6 +375,11 @@ func (b *Buffer) remove(start, end Loc) string {
 	b.Update()
 	return sub
 }
+func (b *Buffer) deleteToEnd(start Loc) {
+	b.IsModified = true
+	b.LineArray.DeleteToEnd(start)
+	b.Update()
+}
 
 // Start returns the location of the first character in the buffer
 func (b *Buffer) Start() Loc {

cmd/micro/settings.go

@@ -181,6 +181,7 @@ func DefaultGlobalSettings() map[string]interface{} {
 		"colorscheme":  "default",
 		"cursorline":   true,
 		"eofnewline":   false,
+		"rmtrailingws": false,
 		"ignorecase":   false,
 		"indentchar":   " ",
 		"infobar":      true,
@@ -212,6 +213,7 @@ func DefaultLocalSettings() map[string]interface{} {
 		"colorcolumn":  float64(0),
 		"cursorline":   true,
 		"eofnewline":   false,
+		"rmtrailingws": false,
 		"filetype":     "Unknown",
 		"ignorecase":   false,
 		"indentchar":   " ",