chore: clean up readline package

if the last item in history is the same as the one being added, skip it.
this reduces the number of history entries. the behaviour is similar to
how most shells maintain history

readline/buffer.go

@@ -10,15 +10,15 @@ import (
 )
 
 type Buffer struct {
-	DisplayPos int
-	Pos        int
-	Buf        *arraylist.List[rune]
-	// LineHasSpace is an arraylist of bools to keep track of whether a line has a space at the end
-	LineHasSpace *arraylist.List[bool]
-	Prompt       *Prompt
-	LineWidth    int
-	Width        int
-	Height       int
+	Prompt    *Prompt
+	LineWidth int
+	Width     int
+	Height    int
+
+	line       *arraylist.List[rune]
+	spaceMask  *arraylist.List[bool]
+	pos        int
+	displayPos int
 }
 
 func NewBuffer(prompt *Prompt) (*Buffer, error) {
@@ -30,130 +30,113 @@ func NewBuffer(prompt *Prompt) (*Buffer, error) {
 
 	lwidth := width - len(prompt.prompt())
 
-	b := &Buffer{
-		DisplayPos:   0,
-		Pos:          0,
-		Buf:          arraylist.New[rune](),
-		LineHasSpace: arraylist.New[bool](),
-		Prompt:       prompt,
-		Width:        width,
-		Height:       height,
-		LineWidth:    lwidth,
-	}
-
-	return b, nil
+	return &Buffer{
+		displayPos: 0,
+		pos:        0,
+		line:       arraylist.New[rune](),
+		spaceMask:  arraylist.New[bool](),
+		Prompt:     prompt,
+		Width:      width,
+		Height:     height,
+		LineWidth:  lwidth,
+	}, nil
 }
 
 func (b *Buffer) GetLineSpacing(line int) bool {
-	hasSpace, _ := b.LineHasSpace.Get(line)
+	hasSpace, _ := b.spaceMask.Get(line)
 	return hasSpace
 }
 
 func (b *Buffer) MoveLeft() {
-	if b.Pos > 0 {
-		// asserts that we retrieve a rune
-		if r, ok := b.Buf.Get(b.Pos - 1); ok {
-			rLength := runewidth.RuneWidth(r)
+	if b.pos > 0 {
+		r, _ := b.line.Get(b.pos - 1)
+		rLength := runewidth.RuneWidth(r)
 
-			if b.DisplayPos%b.LineWidth == 0 {
-				fmt.Print(CursorUp + CursorBOL + CursorRightN(b.Width))
-				if rLength == 2 {
-					fmt.Print(CursorLeft)
-				}
-
-				line := b.DisplayPos/b.LineWidth - 1
-				hasSpace := b.GetLineSpacing(line)
-				if hasSpace {
-					b.DisplayPos -= 1
-					fmt.Print(CursorLeft)
-				}
-			} else {
-				fmt.Print(CursorLeftN(rLength))
+		if b.displayPos%b.LineWidth == 0 {
+			fmt.Print(CursorUp + CursorBOL + CursorRightN(b.Width))
+			if rLength == 2 {
+				fmt.Print(CursorLeft)
 			}
 
-			b.Pos -= 1
-			b.DisplayPos -= rLength
+			line := b.displayPos/b.LineWidth - 1
+			hasSpace := b.GetLineSpacing(line)
+			if hasSpace {
+				b.displayPos -= 1
+				fmt.Print(CursorLeft)
+			}
+		} else {
+			fmt.Print(CursorLeftN(rLength))
 		}
+
+		b.pos -= 1
+		b.displayPos -= rLength
 	}
 }
 
 func (b *Buffer) MoveLeftWord() {
-	if b.Pos > 0 {
-		var foundNonspace bool
-		for {
-			v, _ := b.Buf.Get(b.Pos - 1)
-			if v == ' ' {
-				if foundNonspace {
-					break
-				}
-			} else {
-				foundNonspace = true
-			}
-			b.MoveLeft()
-
-			if b.Pos == 0 {
+	var foundNonspace bool
+	for b.pos > 0 {
+		v, _ := b.line.Get(b.pos - 1)
+		if v == ' ' {
+			if foundNonspace {
 				break
 			}
+		} else {
+			foundNonspace = true
 		}
+		b.MoveLeft()
 	}
 }
 
 func (b *Buffer) MoveRight() {
-	if b.Pos < b.Buf.Size() {
-		if r, ok := b.Buf.Get(b.Pos); ok {
-			rLength := runewidth.RuneWidth(r)
-			b.Pos += 1
-			hasSpace := b.GetLineSpacing(b.DisplayPos / b.LineWidth)
-			b.DisplayPos += rLength
+	if b.pos < b.line.Size() {
+		r, _ := b.line.Get(b.pos)
+		rLength := runewidth.RuneWidth(r)
+		b.pos += 1
+		hasSpace := b.GetLineSpacing(b.displayPos / b.LineWidth)
+		b.displayPos += rLength
 
-			if b.DisplayPos%b.LineWidth == 0 {
-				fmt.Print(CursorDown + CursorBOL + CursorRightN(len(b.Prompt.prompt())))
-			} else if (b.DisplayPos-rLength)%b.LineWidth == b.LineWidth-1 && hasSpace {
-				fmt.Print(CursorDown + CursorBOL + CursorRightN(len(b.Prompt.prompt())+rLength))
-				b.DisplayPos += 1
-			} else if b.LineHasSpace.Size() > 0 && b.DisplayPos%b.LineWidth == b.LineWidth-1 && hasSpace {
-				fmt.Print(CursorDown + CursorBOL + CursorRightN(len(b.Prompt.prompt())))
-				b.DisplayPos += 1
-			} else {
-				fmt.Print(CursorRightN(rLength))
-			}
+		if b.displayPos%b.LineWidth == 0 {
+			fmt.Print(CursorDown + CursorBOL + CursorRightN(len(b.Prompt.prompt())))
+		} else if (b.displayPos-rLength)%b.LineWidth == b.LineWidth-1 && hasSpace {
+			fmt.Print(CursorDown + CursorBOL + CursorRightN(len(b.Prompt.prompt())+rLength))
+			b.displayPos += 1
+		} else if b.spaceMask.Size() > 0 && b.displayPos%b.LineWidth == b.LineWidth-1 && hasSpace {
+			fmt.Print(CursorDown + CursorBOL + CursorRightN(len(b.Prompt.prompt())))
+			b.displayPos += 1
+		} else {
+			fmt.Print(CursorRightN(rLength))
 		}
 	}
 }
 
 func (b *Buffer) MoveRightWord() {
-	if b.Pos < b.Buf.Size() {
-		for {
-			b.MoveRight()
-			v, _ := b.Buf.Get(b.Pos)
-			if v == ' ' {
-				break
-			}
-
-			if b.Pos == b.Buf.Size() {
-				break
-			}
+	for b.pos < b.line.Size() {
+		b.MoveRight()
+		v, _ := b.line.Get(b.pos)
+		if v == ' ' {
+			break
 		}
 	}
 }
 
 func (b *Buffer) MoveToStart() {
-	if b.Pos > 0 {
-		currLine := b.DisplayPos / b.LineWidth
+	if b.pos > 0 {
+		currLine := b.displayPos / b.LineWidth
 		if currLine > 0 {
 			for range currLine {
 				fmt.Print(CursorUp)
 			}
 		}
 		fmt.Print(CursorBOL + CursorRightN(len(b.Prompt.prompt())))
-		b.Pos = 0
-		b.DisplayPos = 0
+		b.pos = 0
+		b.displayPos = 0
 	}
 }
 
 func (b *Buffer) MoveToEnd() {
-	if b.Pos < b.Buf.Size() {
-		currLine := b.DisplayPos / b.LineWidth
+	if b.pos < b.line.Size() {
+		currLine := b.displayPos / b.LineWidth
 		totalLines := b.DisplaySize() / b.LineWidth
 		if currLine < totalLines {
 			for range totalLines - currLine {
@@ -162,18 +145,18 @@ func (b *Buffer) MoveToEnd() {
 			remainder := b.DisplaySize() % b.LineWidth
 			fmt.Print(CursorBOL + CursorRightN(len(b.Prompt.prompt())+remainder))
 		} else {
-			fmt.Print(CursorRightN(b.DisplaySize() - b.DisplayPos))
+			fmt.Print(CursorRightN(b.DisplaySize() - b.displayPos))
 		}
 
-		b.Pos = b.Buf.Size()
-		b.DisplayPos = b.DisplaySize()
+		b.pos = b.line.Size()
+		b.displayPos = b.DisplaySize()
 	}
 }
 
 func (b *Buffer) DisplaySize() int {
 	sum := 0
-	for i := range b.Buf.Size() {
-		if r, ok := b.Buf.Get(i); ok {
+	for i := range b.line.Size() {
+		if r, ok := b.line.Get(i); ok {
 			sum += runewidth.RuneWidth(r)
 		}
 	}
@@ -182,7 +165,7 @@ func (b *Buffer) DisplaySize() int {
 }
 
 func (b *Buffer) Add(r rune) {
-	if b.Pos == b.Buf.Size() {
+	if b.pos == b.line.Size() {
 		b.AddChar(r, false)
 	} else {
 		b.AddChar(r, true)
@@ -191,32 +174,32 @@ func (b *Buffer) Add(r rune) {
 
 func (b *Buffer) AddChar(r rune, insert bool) {
 	rLength := runewidth.RuneWidth(r)
-	b.DisplayPos += rLength
+	b.displayPos += rLength
 
-	if b.Pos > 0 {
-		if b.DisplayPos%b.LineWidth == 0 {
+	if b.pos > 0 {
+		if b.displayPos%b.LineWidth == 0 {
 			fmt.Printf("%c", r)
 			fmt.Printf("\n%s", b.Prompt.AltPrompt)
 
 			if insert {
-				b.LineHasSpace.Set(b.DisplayPos/b.LineWidth-1, false)
+				b.spaceMask.Set(b.displayPos/b.LineWidth-1, false)
 			} else {
-				b.LineHasSpace.Add(false)
+				b.spaceMask.Add(false)
 			}
 
 			// this case occurs when a double-width rune crosses the line boundary
-		} else if b.DisplayPos%b.LineWidth < (b.DisplayPos-rLength)%b.LineWidth {
+		} else if b.displayPos%b.LineWidth < (b.displayPos-rLength)%b.LineWidth {
 			if insert {
 				fmt.Print(ClearToEOL)
 			}
 			fmt.Printf("\n%s", b.Prompt.AltPrompt)
-			b.DisplayPos += 1
+			b.displayPos += 1
 			fmt.Printf("%c", r)
 
 			if insert {
-				b.LineHasSpace.Set(b.DisplayPos/b.LineWidth-1, true)
+				b.spaceMask.Set(b.displayPos/b.LineWidth-1, true)
 			} else {
-				b.LineHasSpace.Add(true)
+				b.spaceMask.Add(true)
 			}
 		} else {
 			fmt.Printf("%c", r)
@@ -226,12 +209,12 @@ func (b *Buffer) AddChar(r rune, insert bool) {
 	}
 
 	if insert {
-		b.Buf.Insert(b.Pos, r)
+		b.line.Insert(b.pos, r)
 	} else {
-		b.Buf.Add(r)
+		b.line.Add(r)
 	}
 
-	b.Pos += 1
+	b.pos += 1
 
 	if insert {
 		b.drawRemaining()
@@ -246,7 +229,7 @@ func (b *Buffer) countRemainingLineWidth(place int) int {
 	for place <= b.LineWidth {
 		counter += 1
 		sum += prevLen
-		if r, ok := b.Buf.Get(b.Pos + counter); ok {
+		if r, ok := b.line.Get(b.pos + counter); ok {
 			place += runewidth.RuneWidth(r)
 			prevLen = len(string(r))
 		} else {
@@ -259,9 +242,9 @@ func (b *Buffer) countRemainingLineWidth(place int) int {
 
 func (b *Buffer) drawRemaining() {
 	var place int
-	remainingText := b.StringN(b.Pos)
-	if b.Pos > 0 {
-		place = b.DisplayPos % b.LineWidth
+	remainingText := b.StringN(b.pos)
+	if b.pos > 0 {
+		place = b.displayPos % b.LineWidth
 	}
 	fmt.Print(CursorHide)
 
@@ -279,14 +262,14 @@ func (b *Buffer) drawRemaining() {
 	}
 
 	if currLineSpace != b.LineWidth-place && currLineSpace != remLength {
-		b.LineHasSpace.Set(b.DisplayPos/b.LineWidth, true)
+		b.spaceMask.Set(b.displayPos/b.LineWidth, true)
 	} else if currLineSpace != b.LineWidth-place {
-		b.LineHasSpace.Remove(b.DisplayPos / b.LineWidth)
+		b.spaceMask.Remove(b.displayPos / b.LineWidth)
 	} else {
-		b.LineHasSpace.Set(b.DisplayPos/b.LineWidth, false)
+		b.spaceMask.Set(b.displayPos/b.LineWidth, false)
 	}
 
-	if (b.DisplayPos+currLineSpace)%b.LineWidth == 0 && currLine == remainingText {
+	if (b.displayPos+currLineSpace)%b.LineWidth == 0 && currLine == remainingText {
 		fmt.Print(CursorRightN(currLineSpace))
 		fmt.Printf("\n%s", b.Prompt.AltPrompt)
 		fmt.Print(CursorUp + CursorBOL + CursorRightN(b.Width-currLineSpace))
@@ -306,9 +289,9 @@ func (b *Buffer) drawRemaining() {
 
 				if displayLength != 0 {
 					if lineLength == b.LineWidth {
-						b.LineHasSpace.Set(b.DisplayPos/b.LineWidth+totalLines-1, false)
+						b.spaceMask.Set(b.displayPos/b.LineWidth+totalLines-1, false)
 					} else {
-						b.LineHasSpace.Set(b.DisplayPos/b.LineWidth+totalLines-1, true)
+						b.spaceMask.Set(b.displayPos/b.LineWidth+totalLines-1, true)
 					}
 				}
 
@@ -321,9 +304,9 @@ func (b *Buffer) drawRemaining() {
 		}
 		fmt.Print(ClearToEOL + CursorUpN(totalLines) + CursorBOL + CursorRightN(b.Width-currLineSpace))
 
-		hasSpace := b.GetLineSpacing(b.DisplayPos / b.LineWidth)
+		hasSpace := b.GetLineSpacing(b.displayPos / b.LineWidth)
 
-		if hasSpace && b.DisplayPos%b.LineWidth != b.LineWidth-1 {
+		if hasSpace && b.displayPos%b.LineWidth != b.LineWidth-1 {
 			fmt.Print(CursorLeft)
 		}
 	}
@@ -332,22 +315,22 @@ func (b *Buffer) drawRemaining() {
 }
 
 func (b *Buffer) Remove() {
-	if b.Buf.Size() > 0 && b.Pos > 0 {
-		if r, ok := b.Buf.Get(b.Pos - 1); ok {
+	if b.line.Size() > 0 && b.pos > 0 {
+		if r, ok := b.line.Get(b.pos - 1); ok {
 			rLength := runewidth.RuneWidth(r)
-			hasSpace := b.GetLineSpacing(b.DisplayPos/b.LineWidth - 1)
+			hasSpace := b.GetLineSpacing(b.displayPos/b.LineWidth - 1)
 
-			if b.DisplayPos%b.LineWidth == 0 {
+			if b.displayPos%b.LineWidth == 0 {
 				// if the user backspaces over the word boundary, do this magic to clear the line
 				// and move to the end of the previous line
 				fmt.Print(CursorBOL + ClearToEOL + CursorUp + CursorBOL + CursorRightN(b.Width))
 
 				if b.DisplaySize()%b.LineWidth < (b.DisplaySize()-rLength)%b.LineWidth {
-					b.LineHasSpace.Remove(b.DisplayPos/b.LineWidth - 1)
+					b.spaceMask.Remove(b.displayPos/b.LineWidth - 1)
 				}
 
 				if hasSpace {
-					b.DisplayPos -= 1
+					b.displayPos -= 1
 					fmt.Print(CursorLeft)
 				}
 
@@ -356,13 +339,13 @@ func (b *Buffer) Remove() {
 				} else {
 					fmt.Print(" " + CursorLeft)
 				}
-			} else if (b.DisplayPos-rLength)%b.LineWidth == 0 && hasSpace {
+			} else if (b.displayPos-rLength)%b.LineWidth == 0 && hasSpace {
 				fmt.Print(CursorBOL + ClearToEOL + CursorUp + CursorBOL + CursorRightN(b.Width))
 
-				if b.Pos == b.Buf.Size() {
-					b.LineHasSpace.Remove(b.DisplayPos/b.LineWidth - 1)
+				if b.pos == b.line.Size() {
+					b.spaceMask.Remove(b.displayPos/b.LineWidth - 1)
 				}
-				b.DisplayPos -= 1
+				b.displayPos -= 1
 			} else {
 				fmt.Print(CursorLeftN(rLength))
 				for range rLength {
@@ -376,18 +359,18 @@ func (b *Buffer) Remove() {
 				eraseExtraLine = true
 			}
 
-			b.Pos -= 1
-			b.DisplayPos -= rLength
-			b.Buf.Remove(b.Pos)
+			b.pos -= 1
+			b.displayPos -= rLength
+			b.line.Remove(b.pos)
 
-			if b.Pos < b.Buf.Size() {
+			if b.pos < b.line.Size() {
 				b.drawRemaining()
 				// this erases a line which is left over when backspacing in the middle of a line and there
 				// are trailing characters which go over the line width boundary
 				if eraseExtraLine {
-					remainingLines := (b.DisplaySize() - b.DisplayPos) / b.LineWidth
+					remainingLines := (b.DisplaySize() - b.displayPos) / b.LineWidth
 					fmt.Print(CursorDownN(remainingLines+1) + CursorBOL + ClearToEOL)
-					place := b.DisplayPos % b.LineWidth
+					place := b.displayPos % b.LineWidth
 					fmt.Print(CursorUpN(remainingLines+1) + CursorRightN(place+len(b.Prompt.prompt())))
 				}
 			}
@@ -396,14 +379,14 @@ func (b *Buffer) Remove() {
 }
 
 func (b *Buffer) Delete() {
-	if b.Buf.Size() > 0 && b.Pos < b.Buf.Size() {
-		b.Buf.Remove(b.Pos)
+	if b.line.Size() > 0 && b.pos < b.line.Size() {
+		b.line.Remove(b.pos)
 		b.drawRemaining()
 		if b.DisplaySize()%b.LineWidth == 0 {
-			if b.DisplayPos != b.DisplaySize() {
-				remainingLines := (b.DisplaySize() - b.DisplayPos) / b.LineWidth
+			if b.displayPos != b.DisplaySize() {
+				remainingLines := (b.DisplaySize() - b.displayPos) / b.LineWidth
 				fmt.Print(CursorDownN(remainingLines) + CursorBOL + ClearToEOL)
-				place := b.DisplayPos % b.LineWidth
+				place := b.displayPos % b.LineWidth
 				fmt.Print(CursorUpN(remainingLines) + CursorRightN(place+len(b.Prompt.prompt())))
 			}
 		}
@@ -411,16 +394,16 @@ func (b *Buffer) Delete() {
 }
 
 func (b *Buffer) DeleteBefore() {
-	if b.Pos > 0 {
-		for cnt := b.Pos - 1; cnt >= 0; cnt-- {
+	if b.pos > 0 {
+		for cnt := b.pos - 1; cnt >= 0; cnt-- {
 			b.Remove()
 		}
 	}
 }
 
 func (b *Buffer) DeleteRemaining() {
-	if b.DisplaySize() > 0 && b.Pos < b.DisplaySize() {
-		charsToDel := b.Buf.Size() - b.Pos
+	if b.DisplaySize() > 0 && b.pos < b.DisplaySize() {
+		charsToDel := b.line.Size() - b.pos
 		for range charsToDel {
 			b.Delete()
 		}
@@ -428,10 +411,10 @@ func (b *Buffer) DeleteRemaining() {
 }
 
 func (b *Buffer) DeleteWord() {
-	if b.Buf.Size() > 0 && b.Pos > 0 {
+	if b.line.Size() > 0 {
 		var foundNonspace bool
-		for {
-			v, _ := b.Buf.Get(b.Pos - 1)
+		for b.pos > 0 {
+			v, _ := b.line.Get(b.pos - 1)
 			if v == ' ' {
 				if !foundNonspace {
 					b.Remove()
@@ -442,10 +425,6 @@ func (b *Buffer) DeleteWord() {
 				foundNonspace = true
 				b.Remove()
 			}
-
-			if b.Pos == 0 {
-				break
-			}
 		}
 	}
 }
@@ -456,10 +435,10 @@ func (b *Buffer) ClearScreen() {
 		ph := b.Prompt.placeholder()
 		fmt.Print(ColorGrey + ph + CursorLeftN(len(ph)) + ColorDefault)
 	} else {
-		currPos := b.DisplayPos
-		currIndex := b.Pos
-		b.Pos = 0
-		b.DisplayPos = 0
+		currPos := b.displayPos
+		currIndex := b.pos
+		b.pos = 0
+		b.displayPos = 0
 		b.drawRemaining()
 		fmt.Print(CursorReset + CursorRightN(len(b.Prompt.prompt())))
 		if currPos > 0 {
@@ -477,21 +456,21 @@ func (b *Buffer) ClearScreen() {
 				fmt.Print(CursorBOL + b.Prompt.AltPrompt)
 			}
 		}
-		b.Pos = currIndex
-		b.DisplayPos = currPos
+		b.pos = currIndex
+		b.displayPos = currPos
 	}
 }
 
 func (b *Buffer) IsEmpty() bool {
-	return b.Buf.Empty()
+	return b.line.Empty()
 }
 
 func (b *Buffer) Replace(r []rune) {
-	b.DisplayPos = 0
-	b.Pos = 0
+	b.displayPos = 0
+	b.pos = 0
 	lineNums := b.DisplaySize() / b.LineWidth
 
-	b.Buf.Clear()
+	b.line.Clear()
 
 	fmt.Print(CursorBOL + ClearToEOL)
 
@@ -517,10 +496,10 @@ func (b *Buffer) StringN(n int) string {
 func (b *Buffer) StringNM(n, m int) string {
 	var s string
 	if m == 0 {
-		m = b.Buf.Size()
+		m = b.line.Size()
 	}
 	for cnt := n; cnt < m; cnt++ {
-		c, _ := b.Buf.Get(cnt)
+		c, _ := b.line.Get(cnt)
 		s += string(c)
 	}
 	return s

readline/history.go

@@ -2,9 +2,7 @@ package readline
 
 import (
 	"bufio"
-	"errors"
 	"fmt"
-	"io"
 	"os"
 	"path/filepath"
 	"strings"
@@ -13,113 +11,91 @@ import (
 )
 
 type History struct {
-	Buf      *arraylist.List[string]
-	Autosave bool
-	Pos      int
-	Limit    int
-	Filename string
-	Enabled  bool
+	Enabled bool
+
+	lines    *arraylist.List[string]
+	limit    int
+	pos      int
+	filename string
 }
 
 func NewHistory() (*History, error) {
 	h := &History{
-		Buf:      arraylist.New[string](),
-		Limit:    100, // resizeme
-		Autosave: true,
-		Enabled:  true,
+		Enabled: true,
+		lines:   arraylist.New[string](),
+		limit:   100, // resizeme
 	}
 
-	err := h.Init()
+	home, err := os.UserHomeDir()
 	if err != nil {
 		return nil, err
 	}
 
+	path := filepath.Join(home, ".ollama", "history")
+	if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
+		return nil, err
+	}
+
+	h.filename = path
+
+	f, err := os.OpenFile(path, os.O_CREATE|os.O_RDONLY, 0o600)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+
+	scanner := bufio.NewScanner(f)
+	for scanner.Scan() {
+		if line := strings.TrimSpace(scanner.Text()); len(line) > 0 {
+			h.Add(line)
+		}
+	}
+
 	return h, nil
 }
 
-func (h *History) Init() error {
-	home, err := os.UserHomeDir()
-	if err != nil {
-		return err
-	}
-
-	path := filepath.Join(home, ".ollama", "history")
-	if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
-		return err
-	}
-
-	h.Filename = path
-
-	f, err := os.OpenFile(path, os.O_CREATE|os.O_RDONLY, 0o600)
-	if err != nil {
-		if errors.Is(err, os.ErrNotExist) {
-			return nil
-		}
-		return err
-	}
-	defer f.Close()
-
-	r := bufio.NewReader(f)
-	for {
-		line, err := r.ReadString('\n')
-		if err != nil {
-			if errors.Is(err, io.EOF) {
-				break
-			}
-			return err
-		}
-
-		line = strings.TrimSpace(line)
-		if len(line) == 0 {
-			continue
-		}
-
-		h.Add(line)
-	}
-
-	return nil
-}
-
 func (h *History) Add(s string) {
-	h.Buf.Add(s)
-	h.Compact()
-	h.Pos = h.Size()
-	if h.Autosave {
+	if latest, _ := h.lines.Get(h.Size() - 1); latest != s {
+		h.lines.Add(s)
+		h.Compact()
 		_ = h.Save()
 	}
+	// always set position to the end
+	h.pos = h.Size()
 }
 
 func (h *History) Compact() {
-	s := h.Buf.Size()
-	if s > h.Limit {
-		for range s - h.Limit {
-			h.Buf.Remove(0)
+	if s := h.lines.Size(); s > h.limit {
+		for range s - h.limit {
+			h.lines.Remove(0)
 		}
 	}
 }
 
 func (h *History) Clear() {
-	h.Buf.Clear()
+	h.lines.Clear()
 }
 
 func (h *History) Prev() (line string) {
-	if h.Pos > 0 {
-		h.Pos -= 1
+	if h.pos > 0 {
+		h.pos -= 1
 	}
-	line, _ = h.Buf.Get(h.Pos)
+	// return first line if at the beginning
+	line, _ = h.lines.Get(h.pos)
 	return line
 }
 
 func (h *History) Next() (line string) {
-	if h.Pos < h.Buf.Size() {
-		h.Pos += 1
-		line, _ = h.Buf.Get(h.Pos)
+	if h.pos < h.lines.Size() {
+		h.pos += 1
+		line, _ = h.lines.Get(h.pos)
 	}
+	// return empty string if at the end
 	return line
 }
 
 func (h *History) Size() int {
-	return h.Buf.Size()
+	return h.lines.Size()
 }
 
 func (h *History) Save() error {
@@ -127,25 +103,21 @@ func (h *History) Save() error {
 		return nil
 	}
 
-	tmpFile := h.Filename + ".tmp"
-
-	f, err := os.OpenFile(tmpFile, os.O_CREATE|os.O_WRONLY|os.O_TRUNC|os.O_APPEND, 0o600)
+	f, err := os.CreateTemp(filepath.Dir(h.filename), "")
 	if err != nil {
 		return err
 	}
-	defer f.Close()
 
-	buf := bufio.NewWriter(f)
-	for cnt := range h.Size() {
-		line, _ := h.Buf.Get(cnt)
-		fmt.Fprintln(buf, line)
-	}
-	buf.Flush()
-	f.Close()
+	func() {
+		defer f.Close()
 
-	if err = os.Rename(tmpFile, h.Filename); err != nil {
-		return err
-	}
+		w := bufio.NewWriter(f)
+		defer w.Flush()
 
-	return nil
+		h.lines.Each(func(i int, line string) {
+			fmt.Fprintln(w, line)
+		})
+	}()
+
+	return os.Rename(f.Name(), h.filename)
 }

readline/readline.go

@@ -91,8 +91,6 @@ func (i *Instance) Readline() (string, error) {
 	var escex bool
 	var metaDel bool
 
-	var currentLineBuf []rune
-
 	for {
 		// don't show placeholder when pasting unless we're in multiline mode
 		showPlaceholder := !i.Pasting || i.Prompt.UseAlt
@@ -116,19 +114,9 @@ func (i *Instance) Readline() (string, error) {
 
 			switch r {
 			case KeyUp:
-				if i.History.Pos > 0 {
-					if i.History.Pos == i.History.Size() {
-						currentLineBuf = []rune(buf.String())
-					}
-					buf.Replace([]rune(i.History.Prev()))
-				}
+				buf.Replace([]rune(i.History.Prev()))
 			case KeyDown:
-				if i.History.Pos < i.History.Size() {
-					buf.Replace([]rune(i.History.Next()))
-					if i.History.Pos == i.History.Size() {
-						buf.Replace(currentLineBuf)
-					}
-				}
+				buf.Replace([]rune(i.History.Next()))
 			case KeyLeft:
 				buf.MoveLeft()
 			case KeyRight: