Simplify ascii helpers

editor/draw.go

@@ -30,7 +30,7 @@ func (e *editor) drawRows(ab *buffer) {
 		if y == e.screen.Rows / 3 {
 			welcome := fmt.Sprintf("Gilo editor -- version %s", KiloVersion)
 			if len(welcome) > e.screen.Cols {
-				welcome = TruncateString(welcome, e.screen.Cols)
+				welcome = truncateString(welcome, e.screen.Cols)
 			}
 
 			padding := (e.screen.Cols - len(welcome)) / 2

editor/editor.go

@@ -31,12 +31,15 @@ func (e *editor) ProcessKeypress() bool {
 	var str string
 
 	ch, _ := terminal.ReadKey()
-	if ch == Ctrl('q') {
+	if isCtrl(ch) {
+		switch ch {
+		case ctrl('q'):
 			// Clean up on exit
 			terminal.Write(terminal.ClearScreen + terminal.ResetCursor)
 
 			return false
 		}
+	}
 
 	if ch == '\x1b' {
 		str = parseEscapeSequence()

editor/fn.go

@@ -2,7 +2,7 @@ package editor
 
 import "strings"
 
-func TruncateString(s string, length int) string {
+func truncateString(s string, length int) string {
 	if length < 1 {
 		return ""
 	}
@@ -23,29 +23,24 @@ func TruncateString(s string, length int) string {
 }
 
 func isAscii(char rune) bool {
-	ord := int(char)
+	return char < 0x80
-
-	return ord < 0x80
 }
 
-func IsCtrl(char rune) bool {
+func isCtrl(char rune) bool {
 	if !isAscii(char) {
 		return false
 	}
 
-	ord := int(char)
+	return char == 0x7f || char < 0x20
-
-	return ord == 0x7f || ord < 0x20
 }
 
 // Return the input code of a Ctrl-key chord.
-func Ctrl(char rune) rune {
+func ctrl(char rune) rune {
-	ord := int(char)
+	ch := char & 0x1f
-	raw := ord & 0x1f
 
-	if !IsCtrl(rune(raw)) {
+	if !isCtrl(ch) {
 		return 0
 	}
 
-	return rune(raw)
+	return ch
 }