got backspace and enter working

file.go

@@ -29,9 +29,9 @@ func fileOpen(fname string) {
 			state.rows = append(state.rows, fread.Text())
 		}
 
-		// if len(state.rows) == 0 || (len(state.rows) == 1 && state.rows[0] == "") {
-		// 	state.rows = []string{" "}
-		// }
+		if len(state.rows) == 0 || (len(state.rows) == 1 && state.rows[0] == "") {
+			state.rows = []string{""}
+		}
 	}
 
 	f.Close()
@@ -47,14 +47,24 @@ func fileSave() {
 	defer f.Close()
 
 	bytesWritten := 0
+	charsWritten := 0
+	linesWritten := 0
 	for _, row := range state.rows {
 		bw, err := fmt.Fprintf(f, "%s\n", row)
 		if err != nil {
 			log.Fatalf("COULD NOT SAVE FILE: %v", err)
 		}
 		bytesWritten += bw
+		charsWritten += len([]rune(row)) + 1
+		linesWritten++
 	}
 
-	state.StatusLine = fmt.Sprintf("'%s' wrote %d bytes.", state.file, bytesWritten)
+	state.StatusLines[1] = fmt.Sprintf(
+		"'%s' saved. %dL, %dC, %d bytes", 
+		state.file, 
+		linesWritten, 
+		charsWritten, 
+		bytesWritten,
+	)
 
 }

input.go

@@ -33,9 +33,7 @@ const (
 
 func editorKeyPresses() bool {
 	char := editorReadKey()
-	state.StatusLine = ""
-
-	editorMoveCaret(char)
+	state.StatusLines[1] = ""
 
 	if char == ctrl_key('r') {
 		uiRefresh()
@@ -55,71 +53,133 @@ func editorKeyPresses() bool {
 		editorRemoveChar(char)
 	} else if char >= 32 && char <= 126 || char == KEY_ENTER || char == KEY_TAB {
 		editorInsertChar(char)
+	} else {
+		editorMoveCaret(char)
 	}
 
 	return true
 }
 
 func editorRemoveChar(char rune) {
-	lineText := state.rows[state.Cy]
-	rl := state.getCurrentRowLen()
-
 	cx := state.Cx
+	cy := state.Cy
+	rc := len(state.rows)
+
+	lt := ""
+	rl := 0
+
+	if rc > 0 {
+		lt = state.rows[cy]
+		rl = state.getCurrentRowLen()
+	}
+
+	// file is empty
+	if rc == 0 && lt == "" {
+		return
+	}
+
+	/*
+		1. Backspace at beginning of a line
+		2. Backspace in middle of a line
+		3. Backspace at end of a line
+		4. Backspace when there are 0 characters in the file
+	*/
 	if char == KEY_BACKSPACE {
-		if cx == 0 && state.Cy > 0 {
-			plt := state.rows[state.Cy-1]
-			state.rows[state.Cy-1] = fmt.Sprintf("%s%s", plt, lineText)
-			if state.Cy < len(state.rows)-1 {
-				state.rows = append(state.rows[:state.Cy-1], state.rows[state.Cy:]...)
-				editorMoveCaret(KEY_UP_ARROW)
-			} else {
-				state.rows = state.rows[:state.Cy-1]
-				state.Cy--
-			}
-			state.Cx = 0
-		} else if cx == 0 {
-			// do nothing because there are no characters
+		if cx == 0 && cy == 0 {
 			return
-		} else {
-			state.StatusLine = fmt.Sprintf("D: %d - %s%s", cx, lineText[:cx-1], lineText[cx:])
-			state.rows[state.Cy] = fmt.Sprintf("%s%s", lineText[:cx-1], lineText[cx:])
+		}
+		// backspace in the middle of a line
+		if cx > 0 && cx < rl {
+			state.rows[cy] = fmt.Sprintf("%s%s", lt[:cx-1], lt[cx:])
 			editorMoveCaret(KEY_LEFT_ARROW)
+			return
+		}
+
+		// backspace at start of line
+		// join lines together and remove
+		if cx == 0 && cy > 0 {
+			plt := state.rows[cy-1]
+			_, highlightedRowLen := renderLine(plt)
+			state.rows[cy-1] = fmt.Sprintf("%s%s", plt, lt)
+
+			editorMoveCaret(KEY_UP_ARROW)
+			for x := 0; x < highlightedRowLen; x++ {
+				editorMoveCaret(KEY_RIGHT_ARROW)
+			}
+
+			// if we're at the last row, make sure to only remove the last line
+			if cy == rc-1 {
+				state.rows = state.rows[:cy]
+			} else {
+				state.rows = append(state.rows[:cy], state.rows[cy+1:]...)
+			}
+
+			return
+		}
+
+		// backspace at end of line
+		if cx == rl {
+			state.rows[cy] = lt[:cx-1]
+			editorMoveCaret(KEY_LEFT_ARROW)
+			return
 		}
 
 	} else if char == KEY_DELETE {
+		// in middle of line
 		if cx < rl-1 {
-			state.rows[state.Cy] = fmt.Sprintf("%s%s", lineText[:cx], lineText[cx+1:])
+			state.rows[state.Cy] = fmt.Sprintf("%s%s", lt[:cx], lt[cx+1:])
 		}
-	} else {
-		return
 	}
-
 }
 
 func editorInsertChar(char rune) {
-	lt := ""
 	cx := state.Cx
-	if len(state.rows) > 0 {
-		lt = state.rows[state.Cy]
-	} else {
-		state.rows = []string{fmt.Sprintf("%c", char)}
-		return
+	cy := state.Cy
+	rc := len(state.rows)
+
+	lt := ""
+	rl := 0
+
+	if rc > 0 {
+		lt = state.rows[cy]
+		rl = state.getCurrentRowLen()
 	}
 
+
+	/*
+		1. Enter at beginning line
+		2. Enter at middle of line
+		3. Enter at end of line
+	*/
 	if char == KEY_ENTER {
-		oldL := lt[:cx]
-		newL := lt[cx:]
-		state.rows[state.Cy] = oldL
-		if state.Cy == len(state.rows)-1 {
-			state.rows[state.Cy] = oldL
-			state.rows = append(state.rows, newL)
-		} else {
-			state.rows = append(append(state.rows[:state.Cy], newL), state.rows[state.Cy:]...)
+		// beginning of line
+		if cx == 0 {
+			if cy == rc {
+				state.rows = append(state.rows, lt)
+			} else if cy < rc {
+				state.rows = append(append(state.rows[:cy], lt), state.rows[cy:]...)
+			}
+			state.rows[cy] = ""
+
+		// end of a line
+		} else if cx >= rl {
+			if cy < rc {
+				state.rows = append(append(state.rows[:cy], ""), state.rows[cy:]...)
+				state.rows[cy] = lt
+			} else if cy == rc {
+				state.rows = append(state.rows[:cy], "")
+			}
+		// mid line
+		} else if cx > 0 {
+			state.rows = append(append(state.rows[:cy], lt[cx:]), state.rows[cy:]...)
+			state.rows[cy] = lt[:cx]
 		}
+
 		state.Cx = 0
 		editorMoveCaret(KEY_DOWN_ARROW)
 	} else {
-		state.rows[state.Cy] = fmt.Sprintf("%s%c%s", lt[:cx], char, lt[cx:])
+		state.StatusLines[1] = fmt.Sprintf("%c %d", char, char)
+		state.rows[cy] = fmt.Sprintf("%s%c%s", lt[:cx], char, lt[cx:])
 		editorMoveCaret(KEY_RIGHT_ARROW)
 	}
 }
@@ -165,6 +225,8 @@ func editorMoveCaret(char rune) {
 	case KEY_END:
 		x = state.Cols - 1
 		break
+	default:
+		return
 	}
 
 	if char == ctrl_key(KEY_DOWN_ARROW) {

main.go

@@ -19,7 +19,7 @@ type editorState struct {
 	Cy         int
 	Rows       int
 	Cols       int
-	StatusLine string
+	StatusLines [2]string
 	DebugLine  string
 	rows       []string
 	rowOffset  int
@@ -66,6 +66,7 @@ func initEditor() {
 	state.Buffer = &bytes.Buffer{}
 	state.rows = []string{fmt.Sprintf("Pound Ed %s", Version)}
 	state.file = ""
+	state.StatusLines = [2]string{}
 }
 
 func cleanup() {

ui.go

@@ -16,8 +16,11 @@ import (
 const (
 	CLEAR             = "\x1b[K"
 	TAB_SIZE          = 8
-	EMPTY_LINE_GUTTER = " x~ "
+	EMPTY_LINE_GUTTER = "  ~ "
 	LINE_GUTTER       = "   "
+	STATUSLINEHEIGHT = 2
+	WHITESPACE = "\xB8"
+	NEWLINE = '\xAC'
 )
 
 func uiDrawRows() {
@@ -36,26 +39,22 @@ func uiDrawRows() {
 		file = "NO FILE"
 	}
 
-	statusLine := fmt.Sprintf(
-		"%s\x1b[1;7m '%s' \x1b[m L:%d/%d C:%d/%d | H:%d W: %d | %s",
+	state.StatusLines[0] = fmt.Sprintf(
+		"%s\x1b[1;7m '%s' \x1b[m L:%d/%d C:%d/%d | H:%d W: %d",
 		CLEAR,
 		file,
 		state.Cy+1,
 		len(state.rows),
 		rx+1,
-		highlightedRowLen,
+		highlightedRowLen+1,
 		state.Rows-1,
-		state.Cols-gutterWidth-1,
-		state.StatusLine)
+		state.Cols-gutterWidth-1)
+
 
 	for y := 0; y < state.Rows; y++ {
-		if y == state.Rows-1 {
-			statusLen := len(statusLine)
-			if statusLen > state.Cols {
-				statusLen = state.Cols
-			}
-			buf.WriteString(statusLine[:statusLen])
-		} else if y < state.Rows && state.Cy < len(state.rows) {
+		if y >= state.Rows-STATUSLINEHEIGHT {
+			buf.WriteString(drawStatusLine(y - (state.Rows - STATUSLINEHEIGHT)))
+		} else if state.Cy < len(state.rows) && y + state.rowOffset < len(state.rows) {
 			rowIdx := y + state.rowOffset
 
 			if rowIdx < len(state.rows) {
@@ -75,8 +74,8 @@ func uiDrawRows() {
 					renderLen = rowEnd
 				}
 
-				if state.colOffset < renderLen {
-					buf.WriteString(row[state.colOffset:renderLen])
+				if state.colOffset <= renderLen {
+					buf.WriteString(fmt.Sprintf("%s%c", row[state.colOffset:renderLen], NEWLINE))
 				}
 
 				if rowLen > rowEnd {
@@ -95,6 +94,16 @@ func uiDrawRows() {
 	}
 }
 
+func drawStatusLine(row int) string {
+		statusLine := state.StatusLines[row]
+		statusLen := len(statusLine)
+		if statusLen > state.Cols {
+			statusLen = state.Cols
+		}
+		return statusLine[:statusLen]
+}
+
+
 func uiRefresh() {
 	buf := state.Buffer
 	fmt.Fprintf(buf, "\x1b[?251")
@@ -222,7 +231,7 @@ func renderLine(line string) (string, int) {
 		if char == '\t' {
 			tabCount++
 			for i := 0; i < TAB_SIZE; i++ {
-				rl += " "
+				rl += WHITESPACE
 			}
 			continue
 		}