feat: yank operator implemented. tested

This is control+d and control+u

internal/action/action.go

@@ -61,6 +61,9 @@ type Model interface {
 	// Window
 	ScrollY() int
 	SetScrollY(y int)
+	WinH() int
+	WinW() int
+	ViewPortH() int
 
 	// Anchor
 	AnchorX() int
@@ -86,6 +89,12 @@ type Model interface {
 	Settings() Settings
 	SetSettings(s Settings)
 
+	// Registers
+	Registers() map[rune]Register
+	GetRegister(name rune) (Register, bool)
+	SetRegister(name rune, t RegisterType, cnt []string) error
+	UpdateDefault(t RegisterType, cnt []string)
+
 	// Mode
 	Mode() Mode
 	SetMode(mode Mode)
@@ -106,10 +115,16 @@ type Position struct {
 type MotionType int
 
 const (
-	Charwise MotionType = iota // h, l, w, e, f, t - operates on characters
+	CharwiseExclusive MotionType = iota // w, b, h, l, 0, ^ - end position not included
+	CharwiseInclusive                   // e, $, f - end position is included
 	Linewise                            // j, k, G, gg, {, } - operates on whole lines
 )
 
+// IsCharwise returns true if the motion type is character-based (not linewise)
+func (mt MotionType) IsCharwise() bool {
+	return mt == CharwiseExclusive || mt == CharwiseInclusive
+}
+
 // Action is the base interface - anything executable
 type Action interface {
 	Execute(m Model) tea.Cmd
@@ -124,7 +139,10 @@ type Motion interface {
 // Operator acts on a range (delete, yank, change)
 type Operator interface {
 	Operate(m Model, start, end Position, mtype MotionType) tea.Cmd
-	// DoublePress handles dd, yy, cc (line-wise)
+}
+
+// DoublePresser is an optional interface for operators that support double-press (dd, yy, cc)
+type DoublePresser interface {
 	DoublePress(m Model, count int) tea.Cmd
 }
 

internal/action/delete.go

@@ -21,3 +21,56 @@ func (a DeleteChar) Execute(m Model) tea.Cmd {
 func (a DeleteChar) WithCount(n int) Action {
 	return DeleteChar{Count: n}
 }
+
+type DeleteToEndOfLine struct {
+	Count int
+}
+
+func (a DeleteToEndOfLine) Execute(m Model) tea.Cmd {
+	// Delete to end of line
+	pos := m.CursorX()
+	line := m.Line(m.CursorY())
+
+	m.SetLine(m.CursorY(), line[:pos])
+	m.SetCursorX(pos - 1)
+
+	// If count is greater, than we will delete the next N - 1 lines below
+	initY := m.CursorY()
+	if a.Count > 1 {
+		// Copied from `internal/operator/delete.go`
+		opCount := min(a.Count-1, m.LineCount()-m.CursorY())
+
+		// Down one
+		m.SetCursorY(initY + 1)
+
+		for range opCount {
+			y := m.CursorY() // Changed from the copied code
+
+			// Stop if were on the starting line
+			if y == initY {
+				break
+			}
+			m.DeleteLine(y)
+
+			if m.LineCount() == 0 {
+				m.InsertLine(0, "")
+			}
+
+			if y >= m.LineCount() {
+				y = m.LineCount() - 1
+			}
+
+			m.SetCursorY(y)
+			m.ClampCursorX()
+		}
+	}
+
+	m.SetCursorY(initY)
+	m.ClampCursorX()
+
+	return nil
+}
+
+func (a DeleteToEndOfLine) WithCount(n int) Action {
+	return DeleteToEndOfLine{Count: n}
+}

internal/action/paste.go

@@ -0,0 +1,149 @@
+package action
+
+import (
+	"fmt"
+	"strings"
+
+	tea "github.com/charmbracelet/bubbletea"
+)
+
+// Paste implements Action (p) - pastes after cursor
+type Paste struct {
+	Count int
+}
+
+func (a Paste) Execute(m Model) tea.Cmd {
+	// Get reg
+	reg, found := m.GetRegister('"')
+	if !found {
+		m.SetCommandError(fmt.Errorf("\"\" register is broken. Uh oh."))
+		return nil
+	}
+
+	// Exit if blank
+	if len(reg.Content) == 0 {
+		return nil
+	}
+
+	switch reg.Type {
+	case LinewiseRegister:
+		{
+			initY := m.CursorY()
+			lines := reg.Content
+			insertPos := initY + 1
+
+			// Run count times
+			for range a.Count {
+				for _, line := range lines {
+					m.InsertLine(insertPos, line)
+					insertPos++
+				}
+			}
+
+			if m.LineCount() > 1 {
+				m.SetCursorY(initY + 1)
+			}
+		}
+	case CharwiseRegister:
+		{
+			lines := reg.Content
+
+			// Shouldn't happen, just a check
+			if len(lines) != 1 {
+				m.SetCommandError(fmt.Errorf("Charwise register should only have a single line of content."))
+				break
+			}
+
+			x := m.CursorX()
+			y := m.CursorY()
+
+			cnt := strings.Repeat(lines[0], max(1, a.Count))
+			curLine := m.Line(y)
+
+			// Catch edge cases, end of line, start of blank line
+			insertAt := min(x+1, len(curLine))
+			newLine := curLine[:insertAt] + cnt + curLine[insertAt:]
+			m.SetLine(y, newLine)
+
+			m.SetCursorX(x + len(cnt))
+			m.ClampCursorX()
+		}
+	default:
+		m.SetCommandError(fmt.Errorf("Register type is not implemented."))
+	}
+
+	return nil
+}
+
+// Ensure Paste implements Repeatable
+var _ Repeatable = Paste{}
+
+func (a Paste) WithCount(n int) Action {
+	return Paste{Count: n}
+}
+
+// PasteBefore implements Action (P) - pastes before cursor
+type PasteBefore struct {
+	Count int
+}
+
+func (a PasteBefore) Execute(m Model) tea.Cmd {
+	// Get reg
+	reg, found := m.GetRegister('"')
+	if !found {
+		m.SetCommandError(fmt.Errorf("\"\" register is broken. Uh oh."))
+		return nil
+	}
+
+	switch reg.Type {
+	case LinewiseRegister:
+		{
+			initY := m.CursorY()
+			lines := reg.Content
+			insertPos := initY // Leave here, this will effectively move the lines below
+
+			// Run count times
+			for range a.Count {
+				for _, line := range lines {
+					m.InsertLine(insertPos, line)
+					insertPos++
+				}
+			}
+		}
+	case CharwiseRegister:
+		{
+			lines := reg.Content
+
+			// Shouldn't happen, just a check
+			if len(lines) != 1 {
+				m.SetCommandError(fmt.Errorf("Charwise register should only have a single line of content."))
+				break
+			}
+
+			x := m.CursorX()
+			y := m.CursorY()
+
+			cnt := strings.Repeat(lines[0], max(1, a.Count))
+			curLine := m.Line(y)
+
+			// Catch edge cases, end of line, start of blank line
+			insertAt := min(x, len(curLine))
+			newLine := curLine[:insertAt] + cnt + curLine[insertAt:]
+			m.SetLine(y, newLine)
+
+			m.SetCursorX(x + len(cnt))
+			m.ClampCursorX()
+		}
+	default:
+		m.SetCommandError(fmt.Errorf("Register type is not implemented."))
+	}
+
+	return nil
+}
+
+// Ensure PasteBefore implements Repeatable
+var _ Repeatable = PasteBefore{}
+
+func (a PasteBefore) WithCount(n int) Action {
+	return PasteBefore{Count: n}
+}

internal/action/register.go

@@ -0,0 +1,75 @@
+package action
+
+type RegisterType int
+
+const (
+	CharwiseRegister RegisterType = iota
+	LinewiseRegister
+	BlockwiseRegister
+)
+
+type Register struct {
+	Type    RegisterType
+	Content []string
+}
+
+func DefaultRegisters() map[rune]Register {
+	reg := make(map[rune]Register)
+
+	addSpecialRegisters(reg)
+	addNamedRegisters(reg)
+	addNumberedRegisters(reg)
+
+	return reg
+}
+
+func addNamedRegisters(reg map[rune]Register) {
+	name := 'a'
+
+	for name <= 'z' {
+		reg[name] = emptyRegister()
+		name++
+	}
+}
+
+func addNumberedRegisters(reg map[rune]Register) {
+	name := '0'
+
+	for name <= '9' {
+		reg[name] = emptyRegister()
+		name++
+	}
+
+}
+
+func addSpecialRegisters(reg map[rune]Register) {
+	// Unnamed (default)
+	reg['"'] = emptyRegister()
+
+	// Black hole (readonly)
+	reg['_'] = emptyRegister()
+
+	// System clipboard
+	reg['*'] = emptyRegister()
+
+	// Small delete? Expression?
+
+	// Last inserted text (readonly)
+	reg['.'] = emptyRegister()
+
+	// Current file name (readonly)
+	reg['%'] = emptyRegister()
+
+	// Last executed command (readonly)
+	reg[':'] = emptyRegister()
+
+	// Alternate (previous) file (readonly)
+	reg['#'] = emptyRegister()
+}
+
+func emptyRegister() Register {
+	return Register{
+		Type:    CharwiseRegister,
+		Content: []string{},
+	}
+}

internal/action/tmp

@@ -0,0 +1,2 @@
+
+hello

internal/command/handlers.go

@@ -53,6 +53,32 @@ func cmdWriteQuit(m action.Model, args []string) tea.Cmd {
 	}
 }
 
+// cmdRegisters handles :register
+func cmdRegisters(m action.Model, args []string) tea.Cmd {
+	// TODO: This is temporary, for debugging
+	if len(args) < 1 {
+		m.SetCommandError(fmt.Errorf("Please provide a name. Register dump not yet implemented."))
+		return nil
+	}
+
+	if len(args[0]) != 1 {
+		m.SetCommandError(fmt.Errorf("Name should be a single character."))
+		return nil
+	}
+
+	name := rune(args[0][0])
+	reg, found := m.GetRegister(name)
+	if !found {
+		m.SetCommandError(fmt.Errorf("Could not find register '%c'.", name))
+		return nil
+	}
+
+	content := strings.Join(reg.Content, "\\n")
+	t := reg.Type
+	m.SetCommandOutput(fmt.Sprintf("Type: %d Name: \"%c Content: %s", t, name, content))
+	return nil
+}
+
 // cmdSet handles :set option[=value]
 // Examples:
 //

internal/command/registry.go

@@ -139,4 +139,11 @@ func (r *Registry) registerDefaults() {
 		ShortForm: "se",
 		Handler:   cmdSet,
 	})
+
+	// Register commands
+	r.Register(Command{
+		Name:      "register",
+		ShortForm: "reg",
+		Handler:   cmdRegisters,
+	})
 }

internal/editor/TEST_HELPERS.md

@@ -0,0 +1,124 @@
+# Test Helper Reference
+
+## Overview
+
+The test helpers use the **functional options pattern** to make test setup flexible and composable.
+
+## Basic Usage
+
+```go
+// Default model (6 lines, cursor at 0,0, terminal 80x24)
+tm := newTestModel(t)
+
+// With custom lines
+tm := newTestModel(t,
+    WithLines([]string{"hello", "world"}),
+)
+
+// With custom cursor position
+tm := newTestModel(t,
+    WithCursorPos(action.Position{Line: 1, Col: 5}),
+)
+
+// With custom terminal size
+tm := newTestModel(t,
+    WithTermSize(120, 40),
+)
+
+// With register content (useful for paste tests)
+tm := newTestModel(t,
+    WithRegister('"', action.CharwiseRegister, []string{"yanked text"}),
+)
+```
+
+## Combining Options
+
+You can combine multiple options in a single call:
+
+```go
+tm := newTestModel(t,
+    WithLines([]string{"line 1", "line 2", "line 3"}),
+    WithCursorPos(action.Position{Line: 1, Col: 0}),
+    WithTermSize(100, 30),
+    WithRegister('"', action.LinewiseRegister, []string{"deleted line"}),
+)
+```
+
+## Available Options
+
+| Option | Parameters | Description |
+|--------|-----------|-------------|
+| `WithLines` | `[]string` | Set buffer lines |
+| `WithCursorPos` | `action.Position` | Set cursor position |
+| `WithTermSize` | `width, height int` | Set terminal dimensions |
+| `WithRegister` | `name rune, type RegisterType, content []string` | Set register content |
+
+## Backward Compatibility
+
+The old helper functions still work for existing tests:
+
+```go
+newTestModelWithLines(t, []string{"a", "b"})
+newTestModelWithCursorPos(t, action.Position{Line: 1, Col: 2})
+newTestModelWithLinesAndCursorPos(t, lines, pos)
+newTestModelWithTermSize(t, lines, pos, width, height)
+```
+
+## Example Test
+
+```go
+func TestPasteCharwise(t *testing.T) {
+    tm := newTestModel(t,
+        WithLines([]string{"hello world"}),
+        WithCursorPos(action.Position{Line: 0, Col: 5}),
+        WithRegister('"', action.CharwiseRegister, []string{"PASTE"}),
+    )
+    
+    sendKeys(tm, "p")
+    m := getFinalModel(t, tm)
+    
+    // Assert expected behavior
+    if m.Line(0) != "hello PASTEworld" {
+        t.Errorf("unexpected result: %s", m.Line(0))
+    }
+}
+```
+
+## Default Values
+
+When options are not specified:
+
+- **Lines**: `[]string{"line 1", "line 2", "line 3", "line 4", "line 5", "line 6"}`
+- **Cursor**: `{Line: 0, Col: 0}`
+- **Terminal**: `80x24`
+- **Register**: None set
+
+## Adding New Options
+
+To add a new option:
+
+1. Add field to `testModelConfig`
+2. Create a `With*` function that returns `TestModelOption`
+3. Apply the option in `newTestModel` after creating the model
+
+Example:
+
+```go
+// In testModelConfig
+type testModelConfig struct {
+    // ... existing fields
+    scrollY int
+}
+
+// New option function
+func WithScrollY(y int) TestModelOption {
+    return func(c *testModelConfig) {
+        c.scrollY = y
+    }
+}
+
+// Apply in newTestModel
+if cfg.scrollY > 0 {
+    m.SetScrollY(cfg.scrollY)
+}
+```

internal/editor/helpers_example_test.go

@@ -0,0 +1,118 @@
+package editor
+
+import (
+	"testing"
+
+	"git.gophernest.net/azpect/TextEditor/internal/action"
+)
+
+// TestHelperExamples demonstrates the different ways to use the test helpers
+func TestHelperExamples(t *testing.T) {
+	t.Run("basic model with defaults", func(t *testing.T) {
+		// Uses default: 6 lines, cursor at 0,0, terminal 80x24
+		tm := newTestModel(t)
+		_ = getFinalModel(t, tm)
+	})
+
+	t.Run("custom lines only", func(t *testing.T) {
+		tm := newTestModel(t,
+			WithLines([]string{"hello", "world"}),
+		)
+		m := getFinalModel(t, tm)
+		if len(m.lines) != 2 {
+			t.Errorf("expected 2 lines, got %d", len(m.lines))
+		}
+	})
+
+	t.Run("custom cursor position", func(t *testing.T) {
+		tm := newTestModel(t,
+			WithCursorPos(action.Position{Line: 2, Col: 3}),
+		)
+		m := getFinalModel(t, tm)
+		if m.CursorY() != 2 || m.CursorX() != 3 {
+			t.Errorf("expected cursor at (2,3), got (%d,%d)", m.CursorY(), m.CursorX())
+		}
+	})
+
+	t.Run("custom terminal size", func(t *testing.T) {
+		tm := newTestModel(t,
+			WithTermSize(120, 40),
+		)
+		m := getFinalModel(t, tm)
+		if m.WinW() != 120 || m.WinH() != 40 {
+			t.Errorf("expected size 120x40, got %dx%d", m.WinW(), m.WinH())
+		}
+	})
+
+	t.Run("with register content for paste testing", func(t *testing.T) {
+		tm := newTestModel(t,
+			WithLines([]string{"hello world"}),
+			WithRegister('"', action.CharwiseRegister, []string{"foo"}),
+		)
+		m := getFinalModel(t, tm)
+
+		reg, ok := m.GetRegister('"')
+		if !ok {
+			t.Fatal("expected register to be set")
+		}
+		if reg.Type != action.CharwiseRegister {
+			t.Errorf("expected charwise register, got %v", reg.Type)
+		}
+		if len(reg.Content) != 1 || reg.Content[0] != "foo" {
+			t.Errorf("expected content ['foo'], got %v", reg.Content)
+		}
+	})
+
+	t.Run("combine multiple options", func(t *testing.T) {
+		tm := newTestModel(t,
+			WithLines([]string{"line one", "line two", "line three"}),
+			WithCursorPos(action.Position{Line: 1, Col: 5}),
+			WithTermSize(100, 30),
+			WithRegister('"', action.LinewiseRegister, []string{"deleted line 1", "deleted line 2"}),
+		)
+		m := getFinalModel(t, tm)
+
+		// Verify all options were applied
+		if len(m.Lines()) != 3 {
+			t.Errorf("expected 3 lines, got %d", len(m.Lines()))
+		}
+		if m.CursorY() != 1 || m.CursorX() != 5 {
+			t.Errorf("expected cursor at (1,5), got (%d,%d)", m.CursorY(), m.CursorX())
+		}
+		if m.WinW() != 100 || m.WinH() != 30 {
+			t.Errorf("expected size 100x30, got %dx%d", m.WinW(), m.WinH())
+		}
+
+		reg, ok := m.GetRegister('"')
+		if !ok || reg.Type != action.LinewiseRegister {
+			t.Error("register not set correctly")
+		}
+	})
+
+	t.Run("backward compatible helpers still work", func(t *testing.T) {
+		// Old style helpers still work for existing tests
+		tm1 := newTestModelWithLines(t, []string{"a", "b"})
+		m1 := getFinalModel(t, tm1)
+		if len(m1.Lines()) != 2 {
+			t.Error("newTestModelWithLines failed")
+		}
+
+		tm2 := newTestModelWithCursorPos(t, action.Position{Line: 1, Col: 2})
+		m2 := getFinalModel(t, tm2)
+		if m2.CursorY() != 1 {
+			t.Error("newTestModelWithCursorPos failed")
+		}
+
+		tm3 := newTestModelWithLinesAndCursorPos(t, []string{"x"}, action.Position{Line: 0, Col: 0})
+		m3 := getFinalModel(t, tm3)
+		if len(m3.Lines()) != 1 {
+			t.Error("newTestModelWithLinesAndCursorPos failed")
+		}
+
+		tm4 := newTestModelWithTermSize(t, []string{"y"}, action.Position{Line: 0, Col: 0}, 50, 20)
+		m4 := getFinalModel(t, tm4)
+		if m4.WinW() != 50 {
+			t.Error("newTestModelWithTermSize failed")
+		}
+	})
+}

internal/editor/helpers_test.go

@@ -23,6 +23,8 @@ func sendKeys(tm *teatest.TestModel, keys ...string) {
 			tm.Send(tea.KeyMsg{Type: tea.KeyCtrlC})
 		case "ctrl+d":
 			tm.Send(tea.KeyMsg{Type: tea.KeyCtrlD})
+		case "ctrl+u":
+			tm.Send(tea.KeyMsg{Type: tea.KeyCtrlU})
 		case "ctrl+v":
 			tm.Send(tea.KeyMsg{Type: tea.KeyCtrlV})
 		case "ctrl+w":
@@ -33,27 +35,91 @@ func sendKeys(tm *teatest.TestModel, keys ...string) {
 	}
 }
 
-// newTestModel creates a test model with default content
+// TestModelOption is a functional option for configuring test models
-func newTestModel(t *testing.T) *teatest.TestModel {
+type TestModelOption func(*testModelConfig)
-	lines := []string{"line 1", "line 2", "line 3", "line 4", "line 5", "line 6"}
+
-	return teatest.NewTestModel(t, NewModel(lines, action.Position{Col: 0, Line: 0}), teatest.WithInitialTermSize(80, 24))
+type testModelConfig struct {
+	lines      []string
+	pos        action.Position
+	width      int
+	height     int
+	regName    rune
+	regType    action.RegisterType
+	regContent []string
 }
 
+// WithLines sets the initial buffer lines
+func WithLines(lines []string) TestModelOption {
+	return func(c *testModelConfig) {
+		c.lines = lines
+	}
+}
+
+// WithCursorPos sets the initial cursor position
+func WithCursorPos(pos action.Position) TestModelOption {
+	return func(c *testModelConfig) {
+		c.pos = pos
+	}
+}
+
+// WithTermSize sets the terminal dimensions
+func WithTermSize(width, height int) TestModelOption {
+	return func(c *testModelConfig) {
+		c.width = width
+		c.height = height
+	}
+}
+
+// WithRegister sets a register's content
+func WithRegister(name rune, regType action.RegisterType, content []string) TestModelOption {
+	return func(c *testModelConfig) {
+		c.regName = name
+		c.regType = regType
+		c.regContent = content
+	}
+}
+
+// newTestModel creates a test model with optional configuration
+func newTestModel(t *testing.T, opts ...TestModelOption) *teatest.TestModel {
+	// Default configuration
+	cfg := testModelConfig{
+		lines:  []string{"line 1", "line 2", "line 3", "line 4", "line 5", "line 6"},
+		pos:    action.Position{Col: 0, Line: 0},
+		width:  80,
+		height: 24,
+	}
+
+	// Apply options
+	for _, opt := range opts {
+		opt(&cfg)
+	}
+
+	// Create model
+	m := NewModel(cfg.lines, cfg.pos)
+
+	// Set register if provided
+	if cfg.regContent != nil {
+		m.SetRegister(cfg.regName, cfg.regType, cfg.regContent)
+	}
+
+	return teatest.NewTestModel(t, m, teatest.WithInitialTermSize(cfg.width, cfg.height))
+}
+
+// Convenience functions for backward compatibility
 func newTestModelWithLines(t *testing.T, lines []string) *teatest.TestModel {
-	return teatest.NewTestModel(t, NewModel(lines, action.Position{Col: 0, Line: 0}), teatest.WithInitialTermSize(80, 24))
+	return newTestModel(t, WithLines(lines))
 }
 
 func newTestModelWithCursorPos(t *testing.T, pos action.Position) *teatest.TestModel {
-	lines := []string{"line 1", "line 2", "line 3", "line 4", "line 5", "line 6"}
+	return newTestModel(t, WithCursorPos(pos))
-	return teatest.NewTestModel(t, NewModel(lines, pos), teatest.WithInitialTermSize(80, 24))
 }
 
 func newTestModelWithLinesAndCursorPos(t *testing.T, lines []string, pos action.Position) *teatest.TestModel {
-	return teatest.NewTestModel(t, NewModel(lines, pos), teatest.WithInitialTermSize(80, 24))
+	return newTestModel(t, WithLines(lines), WithCursorPos(pos))
 }
 
 func newTestModelWithTermSize(t *testing.T, lines []string, pos action.Position, width, height int) *teatest.TestModel {
-	return teatest.NewTestModel(t, NewModel(lines, pos), teatest.WithInitialTermSize(width, height))
+	return newTestModel(t, WithLines(lines), WithCursorPos(pos), WithTermSize(width, height))
 }
 
 // getFinalModel extracts the final model state (sends ctrl+c to quit first)

internal/editor/integration_delete_test.go

@@ -86,3 +86,92 @@ func TestDeleteCharWithCount(t *testing.T) {
 		}
 	})
 }
+
+func TestDeleteToEndOfLine(t *testing.T) {
+	t.Run("test 'D' deletes to end of line", func(t *testing.T) {
+		lines := []string{"hello world"}
+		tm := newTestModelWithLinesAndCursorPos(t, lines, action.Position{Col: 5, Line: 0})
+		sendKeys(tm, "D")
+
+		m := getFinalModel(t, tm)
+		if m.Line(0) != "hello" {
+			t.Errorf("Line(0) = %q, want 'hello'", m.Line(0))
+		}
+	})
+
+	t.Run("test 'D' from start of line deletes entire content", func(t *testing.T) {
+		lines := []string{"hello world"}
+		tm := newTestModelWithLines(t, lines)
+		sendKeys(tm, "D")
+
+		m := getFinalModel(t, tm)
+		if m.Line(0) != "" {
+			t.Errorf("Line(0) = %q, want ''", m.Line(0))
+		}
+	})
+
+	t.Run("test 'D' at last character", func(t *testing.T) {
+		lines := []string{"hello"}
+		tm := newTestModelWithLinesAndCursorPos(t, lines, action.Position{Col: 4, Line: 0})
+		sendKeys(tm, "D")
+
+		m := getFinalModel(t, tm)
+		if m.Line(0) != "hell" {
+			t.Errorf("Line(0) = %q, want 'hell'", m.Line(0))
+		}
+	})
+
+	t.Run("test 'D' cursor position after delete", func(t *testing.T) {
+		lines := []string{"hello world"}
+		tm := newTestModelWithLinesAndCursorPos(t, lines, action.Position{Col: 5, Line: 0})
+		sendKeys(tm, "D")
+
+		m := getFinalModel(t, tm)
+		// Cursor should move to last character of remaining text
+		if m.CursorX() != 4 {
+			t.Errorf("CursorX() = %d, want 4", m.CursorX())
+		}
+	})
+
+	t.Run("test 'D' deletes nothing on blank line", func(t *testing.T) {
+		lines := []string{""}
+		tm := newTestModelWithLines(t, lines)
+		sendKeys(tm, "D")
+
+		m := getFinalModel(t, tm)
+		if m.Line(0) != "" {
+			t.Errorf("Line(0) = %q, want ''", m.Line(0))
+		}
+	})
+
+	t.Run("test 'D' with count deletes following lines", func(t *testing.T) {
+		lines := []string{"hello", "world", "hi", "mom"}
+		tm := newTestModelWithLinesAndCursorPos(t, lines, action.Position{Col: 2, Line: 0})
+		sendKeys(tm, "2", "D")
+
+		m := getFinalModel(t, tm)
+		if m.LineCount() != 3 {
+			t.Errorf("LineCount() = %q, want '3'", m.LineCount())
+		}
+		if m.Line(0) != "he" {
+			t.Errorf("Line(0) = %q, want 'he'", m.Line(0))
+		}
+		if m.Line(1) != "hi" {
+			t.Errorf("Line(1) = %q, want 'hi'", m.Line(1))
+		}
+	})
+
+	t.Run("test 'D' with count deletes following lines with overflow", func(t *testing.T) {
+		lines := []string{"hello", "world", "hi", "mom"}
+		tm := newTestModelWithLinesAndCursorPos(t, lines, action.Position{Col: 2, Line: 0})
+		sendKeys(tm, "8", "D")
+
+		m := getFinalModel(t, tm)
+		if m.LineCount() != 1 {
+			t.Errorf("LineCount() = %q, want '1'", m.LineCount())
+		}
+		if m.Line(0) != "he" {
+			t.Errorf("Line(0) = %q, want 'he'", m.Line(0))
+		}
+	})
+}

internal/editor/integration_operator_delete_test.go

@@ -615,9 +615,9 @@ func TestDeleteOperatorWithWordMotion(t *testing.T) {
 		sendKeys(tm, "d", "e")
 
 		m := getFinalModel(t, tm)
-		// 'e' is inclusive - deletes "hello" (cols 0-4 inclusive)
+		// 'e' is inclusive - deletes "hello" (cols 0-4 inclusive), leaves " world"
-		if m.Line(0) != "o world" {
+		if m.Line(0) != " world" {
-			t.Errorf("Line(0) = %q, want \"o world\"", m.Line(0))
+			t.Errorf("Line(0) = %q, want \" world\"", m.Line(0))
 		}
 		if m.CursorX() != 0 {
 			t.Errorf("CursorX() = %d, want 0", m.CursorX())
@@ -631,8 +631,8 @@ func TestDeleteOperatorWithWordMotion(t *testing.T) {
 
 		m := getFinalModel(t, tm)
 		// From 'l' (col 2) to 'o' (col 4) inclusive → deletes "llo"
-		if m.Line(0) != "heo world" {
+		if m.Line(0) != "he world" {
-			t.Errorf("Line(0) = %q, want \"heo world\"", m.Line(0))
+			t.Errorf("Line(0) = %q, want \"he world\"", m.Line(0))
 		}
 	})
 
@@ -643,8 +643,8 @@ func TestDeleteOperatorWithWordMotion(t *testing.T) {
 
 		m := getFinalModel(t, tm)
 		// From 'o' of "hello" (col 4) to 'd' of "world" (col 10) inclusive
-		if m.Line(0) != "helld" {
+		if m.Line(0) != "hell" {
-			t.Errorf("Line(0) = %q, want \"helld\"", m.Line(0))
+			t.Errorf("Line(0) = %q, want \"hell\"", m.Line(0))
 		}
 	})
 
@@ -654,9 +654,9 @@ func TestDeleteOperatorWithWordMotion(t *testing.T) {
 		sendKeys(tm, "2", "d", "e")
 
 		m := getFinalModel(t, tm)
-		// Deletes "one" and "two" (to end of second word inclusive)
+		// Deletes "one" and " two" (to end of second word inclusive)
-		if m.Line(0) != "o three four" {
+		if m.Line(0) != " three four" {
-			t.Errorf("Line(0) = %q, want \"o three four\"", m.Line(0))
+			t.Errorf("Line(0) = %q, want \" three four\"", m.Line(0))
 		}
 	})
 

internal/editor/integration_paste_test.go

@@ -0,0 +1,576 @@
+package editor
+
+import (
+	"testing"
+
+	"git.gophernest.net/azpect/TextEditor/internal/action"
+)
+
+func TestPasteLinewiseBasic(t *testing.T) {
+	t.Run("p pastes single line after cursor line", func(t *testing.T) {
+		tm := newTestModel(t,
+			WithLines([]string{"line 1", "line 2"}),
+			WithCursorPos(action.Position{Line: 0, Col: 0}),
+			WithRegister('"', action.LinewiseRegister, []string{"inserted"}),
+		)
+		sendKeys(tm, "p")
+
+		m := getFinalModel(t, tm)
+		if m.LineCount() != 3 {
+			t.Errorf("LineCount() = %d, want 3", m.LineCount())
+		}
+		if m.Line(0) != "line 1" {
+			t.Errorf("Line(0) = %q, want 'line 1'", m.Line(0))
+		}
+		if m.Line(1) != "inserted" {
+			t.Errorf("Line(1) = %q, want 'inserted'", m.Line(1))
+		}
+		if m.Line(2) != "line 2" {
+			t.Errorf("Line(2) = %q, want 'line 2'", m.Line(2))
+		}
+	})
+
+	t.Run("p moves cursor to first pasted line", func(t *testing.T) {
+		tm := newTestModel(t,
+			WithLines([]string{"line 1", "line 2", "line 3"}),
+			WithCursorPos(action.Position{Line: 0, Col: 5}),
+			WithRegister('"', action.LinewiseRegister, []string{"inserted"}),
+		)
+		sendKeys(tm, "p")
+
+		m := getFinalModel(t, tm)
+		if m.CursorY() != 1 {
+			t.Errorf("CursorY() = %d, want 1", m.CursorY())
+		}
+	})
+
+	t.Run("p from middle of file", func(t *testing.T) {
+		tm := newTestModel(t,
+			WithLines([]string{"line 1", "line 2", "line 3"}),
+			WithCursorPos(action.Position{Line: 1, Col: 0}),
+			WithRegister('"', action.LinewiseRegister, []string{"inserted"}),
+		)
+		sendKeys(tm, "p")
+
+		m := getFinalModel(t, tm)
+		if m.LineCount() != 4 {
+			t.Errorf("LineCount() = %d, want 4", m.LineCount())
+		}
+		if m.Line(2) != "inserted" {
+			t.Errorf("Line(2) = %q, want 'inserted'", m.Line(2))
+		}
+		if m.CursorY() != 2 {
+			t.Errorf("CursorY() = %d, want 2", m.CursorY())
+		}
+	})
+
+	t.Run("p at end of file", func(t *testing.T) {
+		tm := newTestModel(t,
+			WithLines([]string{"line 1", "line 2"}),
+			WithCursorPos(action.Position{Line: 1, Col: 0}),
+			WithRegister('"', action.LinewiseRegister, []string{"inserted"}),
+		)
+		sendKeys(tm, "p")
+
+		m := getFinalModel(t, tm)
+		if m.LineCount() != 3 {
+			t.Errorf("LineCount() = %d, want 3", m.LineCount())
+		}
+		if m.Line(2) != "inserted" {
+			t.Errorf("Line(2) = %q, want 'inserted'", m.Line(2))
+		}
+	})
+}
+
+func TestPasteLinewiseMultipleLines(t *testing.T) {
+	t.Run("p pastes multiple lines in correct order", func(t *testing.T) {
+		tm := newTestModel(t,
+			WithLines([]string{"line 1", "line 2"}),
+			WithCursorPos(action.Position{Line: 0, Col: 0}),
+			WithRegister('"', action.LinewiseRegister, []string{"first", "second", "third"}),
+		)
+		sendKeys(tm, "p")
+
+		m := getFinalModel(t, tm)
+		if m.LineCount() != 5 {
+			t.Errorf("LineCount() = %d, want 5", m.LineCount())
+		}
+		if m.Line(0) != "line 1" {
+			t.Errorf("Line(0) = %q, want 'line 1'", m.Line(0))
+		}
+		if m.Line(1) != "first" {
+			t.Errorf("Line(1) = %q, want 'first'", m.Line(1))
+		}
+		if m.Line(2) != "second" {
+			t.Errorf("Line(2) = %q, want 'second'", m.Line(2))
+		}
+		if m.Line(3) != "third" {
+			t.Errorf("Line(3) = %q, want 'third'", m.Line(3))
+		}
+		if m.Line(4) != "line 2" {
+			t.Errorf("Line(4) = %q, want 'line 2'", m.Line(4))
+		}
+	})
+
+	t.Run("p with multiple lines moves cursor to first pasted line", func(t *testing.T) {
+		tm := newTestModel(t,
+			WithLines([]string{"line 1", "line 2"}),
+			WithCursorPos(action.Position{Line: 0, Col: 0}),
+			WithRegister('"', action.LinewiseRegister, []string{"first", "second"}),
+		)
+		sendKeys(tm, "p")
+
+		m := getFinalModel(t, tm)
+		if m.CursorY() != 1 {
+			t.Errorf("CursorY() = %d, want 1", m.CursorY())
+		}
+	})
+}
+
+func TestPasteLinewiseWithCount(t *testing.T) {
+	t.Run("2p pastes content twice", func(t *testing.T) {
+		tm := newTestModel(t,
+			WithLines([]string{"line 1", "line 2"}),
+			WithCursorPos(action.Position{Line: 0, Col: 0}),
+			WithRegister('"', action.LinewiseRegister, []string{"inserted"}),
+		)
+		sendKeys(tm, "2", "p")
+
+		m := getFinalModel(t, tm)
+		if m.LineCount() != 4 {
+			t.Errorf("LineCount() = %d, want 4", m.LineCount())
+		}
+		// Both "inserted" lines should appear after line 1
+		if m.Line(1) != "inserted" {
+			t.Errorf("Line(1) = %q, want 'inserted'", m.Line(1))
+		}
+		if m.Line(2) != "inserted" {
+			t.Errorf("Line(2) = %q, want 'inserted'", m.Line(2))
+		}
+		if m.Line(3) != "line 2" {
+			t.Errorf("Line(3) = %q, want 'line 2'", m.Line(3))
+		}
+	})
+
+	t.Run("3p pastes content three times", func(t *testing.T) {
+		tm := newTestModel(t,
+			WithLines([]string{"original"}),
+			WithCursorPos(action.Position{Line: 0, Col: 0}),
+			WithRegister('"', action.LinewiseRegister, []string{"pasted"}),
+		)
+		sendKeys(tm, "3", "p")
+
+		m := getFinalModel(t, tm)
+		if m.LineCount() != 4 {
+			t.Errorf("LineCount() = %d, want 4", m.LineCount())
+		}
+		for i := 1; i <= 3; i++ {
+			if m.Line(i) != "pasted" {
+				t.Errorf("Line(%d) = %q, want 'pasted'", i, m.Line(i))
+			}
+		}
+	})
+
+	t.Run("2p with multiple lines pastes all lines twice in order", func(t *testing.T) {
+		tm := newTestModel(t,
+			WithLines([]string{"original"}),
+			WithCursorPos(action.Position{Line: 0, Col: 0}),
+			WithRegister('"', action.LinewiseRegister, []string{"first", "second"}),
+		)
+		sendKeys(tm, "2", "p")
+
+		m := getFinalModel(t, tm)
+		// Should be: original, first, second, first, second
+		if m.LineCount() != 5 {
+			t.Errorf("LineCount() = %d, want 5", m.LineCount())
+		}
+		if m.Line(0) != "original" {
+			t.Errorf("Line(0) = %q, want 'original'", m.Line(0))
+		}
+		if m.Line(1) != "first" {
+			t.Errorf("Line(1) = %q, want 'first'", m.Line(1))
+		}
+		if m.Line(2) != "second" {
+			t.Errorf("Line(2) = %q, want 'second'", m.Line(2))
+		}
+		if m.Line(3) != "first" {
+			t.Errorf("Line(3) = %q, want 'first'", m.Line(3))
+		}
+		if m.Line(4) != "second" {
+			t.Errorf("Line(4) = %q, want 'second'", m.Line(4))
+		}
+	})
+
+	t.Run("count paste moves cursor to first pasted line", func(t *testing.T) {
+		tm := newTestModel(t,
+			WithLines([]string{"line 1", "line 2"}),
+			WithCursorPos(action.Position{Line: 0, Col: 0}),
+			WithRegister('"', action.LinewiseRegister, []string{"inserted"}),
+		)
+		sendKeys(tm, "3", "p")
+
+		m := getFinalModel(t, tm)
+		if m.CursorY() != 1 {
+			t.Errorf("CursorY() = %d, want 1", m.CursorY())
+		}
+	})
+}
+
+// Tests for P (paste before)
+
+func TestPasteBeforeLinewiseBasic(t *testing.T) {
+	t.Run("P pastes single line before cursor line", func(t *testing.T) {
+		tm := newTestModel(t,
+			WithLines([]string{"line 1", "line 2"}),
+			WithCursorPos(action.Position{Line: 1, Col: 0}),
+			WithRegister('"', action.LinewiseRegister, []string{"inserted"}),
+		)
+		sendKeys(tm, "P")
+
+		m := getFinalModel(t, tm)
+		if m.LineCount() != 3 {
+			t.Errorf("LineCount() = %d, want 3", m.LineCount())
+		}
+		if m.Line(0) != "line 1" {
+			t.Errorf("Line(0) = %q, want 'line 1'", m.Line(0))
+		}
+		if m.Line(1) != "inserted" {
+			t.Errorf("Line(1) = %q, want 'inserted'", m.Line(1))
+		}
+		if m.Line(2) != "line 2" {
+			t.Errorf("Line(2) = %q, want 'line 2'", m.Line(2))
+		}
+	})
+
+	t.Run("P moves cursor to first pasted line", func(t *testing.T) {
+		tm := newTestModel(t,
+			WithLines([]string{"line 1", "line 2", "line 3"}),
+			WithCursorPos(action.Position{Line: 1, Col: 5}),
+			WithRegister('"', action.LinewiseRegister, []string{"inserted"}),
+		)
+		sendKeys(tm, "P")
+
+		m := getFinalModel(t, tm)
+		if m.CursorY() != 1 {
+			t.Errorf("CursorY() = %d, want 1", m.CursorY())
+		}
+	})
+
+	t.Run("P at first line pastes at very top", func(t *testing.T) {
+		tm := newTestModel(t,
+			WithLines([]string{"line 1", "line 2"}),
+			WithCursorPos(action.Position{Line: 0, Col: 0}),
+			WithRegister('"', action.LinewiseRegister, []string{"inserted"}),
+		)
+		sendKeys(tm, "P")
+
+		m := getFinalModel(t, tm)
+		if m.LineCount() != 3 {
+			t.Errorf("LineCount() = %d, want 3", m.LineCount())
+		}
+		if m.Line(0) != "inserted" {
+			t.Errorf("Line(0) = %q, want 'inserted'", m.Line(0))
+		}
+		if m.Line(1) != "line 1" {
+			t.Errorf("Line(1) = %q, want 'line 1'", m.Line(1))
+		}
+		if m.CursorY() != 0 {
+			t.Errorf("CursorY() = %d, want 0", m.CursorY())
+		}
+	})
+
+	t.Run("P from middle of file", func(t *testing.T) {
+		tm := newTestModel(t,
+			WithLines([]string{"line 1", "line 2", "line 3"}),
+			WithCursorPos(action.Position{Line: 1, Col: 0}),
+			WithRegister('"', action.LinewiseRegister, []string{"inserted"}),
+		)
+		sendKeys(tm, "P")
+
+		m := getFinalModel(t, tm)
+		if m.LineCount() != 4 {
+			t.Errorf("LineCount() = %d, want 4", m.LineCount())
+		}
+		if m.Line(1) != "inserted" {
+			t.Errorf("Line(1) = %q, want 'inserted'", m.Line(1))
+		}
+		if m.Line(2) != "line 2" {
+			t.Errorf("Line(2) = %q, want 'line 2'", m.Line(2))
+		}
+	})
+}
+
+func TestPasteBeforeLinewiseMultipleLines(t *testing.T) {
+	t.Run("P pastes multiple lines in correct order", func(t *testing.T) {
+		tm := newTestModel(t,
+			WithLines([]string{"line 1", "line 2"}),
+			WithCursorPos(action.Position{Line: 1, Col: 0}),
+			WithRegister('"', action.LinewiseRegister, []string{"first", "second", "third"}),
+		)
+		sendKeys(tm, "P")
+
+		m := getFinalModel(t, tm)
+		if m.LineCount() != 5 {
+			t.Errorf("LineCount() = %d, want 5", m.LineCount())
+		}
+		if m.Line(0) != "line 1" {
+			t.Errorf("Line(0) = %q, want 'line 1'", m.Line(0))
+		}
+		if m.Line(1) != "first" {
+			t.Errorf("Line(1) = %q, want 'first'", m.Line(1))
+		}
+		if m.Line(2) != "second" {
+			t.Errorf("Line(2) = %q, want 'second'", m.Line(2))
+		}
+		if m.Line(3) != "third" {
+			t.Errorf("Line(3) = %q, want 'third'", m.Line(3))
+		}
+		if m.Line(4) != "line 2" {
+			t.Errorf("Line(4) = %q, want 'line 2'", m.Line(4))
+		}
+	})
+
+	t.Run("P with multiple lines moves cursor to first pasted line", func(t *testing.T) {
+		tm := newTestModel(t,
+			WithLines([]string{"line 1", "line 2"}),
+			WithCursorPos(action.Position{Line: 1, Col: 0}),
+			WithRegister('"', action.LinewiseRegister, []string{"first", "second"}),
+		)
+		sendKeys(tm, "P")
+
+		m := getFinalModel(t, tm)
+		if m.CursorY() != 1 {
+			t.Errorf("CursorY() = %d, want 1", m.CursorY())
+		}
+	})
+}
+
+func TestPasteBeforeLinewiseWithCount(t *testing.T) {
+	t.Run("2P pastes content twice", func(t *testing.T) {
+		tm := newTestModel(t,
+			WithLines([]string{"line 1", "line 2"}),
+			WithCursorPos(action.Position{Line: 1, Col: 0}),
+			WithRegister('"', action.LinewiseRegister, []string{"inserted"}),
+		)
+		sendKeys(tm, "2", "P")
+
+		m := getFinalModel(t, tm)
+		if m.LineCount() != 4 {
+			t.Errorf("LineCount() = %d, want 4", m.LineCount())
+		}
+		// Both "inserted" lines should appear before line 2
+		if m.Line(1) != "inserted" {
+			t.Errorf("Line(1) = %q, want 'inserted'", m.Line(1))
+		}
+		if m.Line(2) != "inserted" {
+			t.Errorf("Line(2) = %q, want 'inserted'", m.Line(2))
+		}
+		if m.Line(3) != "line 2" {
+			t.Errorf("Line(3) = %q, want 'line 2'", m.Line(3))
+		}
+	})
+
+	t.Run("3P pastes content three times", func(t *testing.T) {
+		tm := newTestModel(t,
+			WithLines([]string{"original"}),
+			WithCursorPos(action.Position{Line: 0, Col: 0}),
+			WithRegister('"', action.LinewiseRegister, []string{"pasted"}),
+		)
+		sendKeys(tm, "3", "P")
+
+		m := getFinalModel(t, tm)
+		if m.LineCount() != 4 {
+			t.Errorf("LineCount() = %d, want 4", m.LineCount())
+		}
+		for i := 0; i < 3; i++ {
+			if m.Line(i) != "pasted" {
+				t.Errorf("Line(%d) = %q, want 'pasted'", i, m.Line(i))
+			}
+		}
+		if m.Line(3) != "original" {
+			t.Errorf("Line(3) = %q, want 'original'", m.Line(3))
+		}
+	})
+
+	t.Run("2P with multiple lines pastes all lines twice in order", func(t *testing.T) {
+		tm := newTestModel(t,
+			WithLines([]string{"original"}),
+			WithCursorPos(action.Position{Line: 0, Col: 0}),
+			WithRegister('"', action.LinewiseRegister, []string{"first", "second"}),
+		)
+		sendKeys(tm, "2", "P")
+
+		m := getFinalModel(t, tm)
+		// Should be: first, second, first, second, original
+		if m.LineCount() != 5 {
+			t.Errorf("LineCount() = %d, want 5", m.LineCount())
+		}
+		if m.Line(0) != "first" {
+			t.Errorf("Line(0) = %q, want 'first'", m.Line(0))
+		}
+		if m.Line(1) != "second" {
+			t.Errorf("Line(1) = %q, want 'second'", m.Line(1))
+		}
+		if m.Line(2) != "first" {
+			t.Errorf("Line(2) = %q, want 'first'", m.Line(2))
+		}
+		if m.Line(3) != "second" {
+			t.Errorf("Line(3) = %q, want 'second'", m.Line(3))
+		}
+		if m.Line(4) != "original" {
+			t.Errorf("Line(4) = %q, want 'original'", m.Line(4))
+		}
+	})
+
+	t.Run("count paste before moves cursor to first pasted line", func(t *testing.T) {
+		tm := newTestModel(t,
+			WithLines([]string{"line 1", "line 2"}),
+			WithCursorPos(action.Position{Line: 1, Col: 0}),
+			WithRegister('"', action.LinewiseRegister, []string{"inserted"}),
+		)
+		sendKeys(tm, "3", "P")
+
+		m := getFinalModel(t, tm)
+		if m.CursorY() != 1 {
+			t.Errorf("CursorY() = %d, want 1", m.CursorY())
+		}
+	})
+}
+
+func TestPasteBeforeLinewiseEdgeCases(t *testing.T) {
+	t.Run("P on single line buffer", func(t *testing.T) {
+		tm := newTestModel(t,
+			WithLines([]string{"only line"}),
+			WithCursorPos(action.Position{Line: 0, Col: 0}),
+			WithRegister('"', action.LinewiseRegister, []string{"inserted"}),
+		)
+		sendKeys(tm, "P")
+
+		m := getFinalModel(t, tm)
+		if m.LineCount() != 2 {
+			t.Errorf("LineCount() = %d, want 2", m.LineCount())
+		}
+		if m.Line(0) != "inserted" {
+			t.Errorf("Line(0) = %q, want 'inserted'", m.Line(0))
+		}
+		if m.Line(1) != "only line" {
+			t.Errorf("Line(1) = %q, want 'only line'", m.Line(1))
+		}
+	})
+
+	t.Run("P with empty register content does nothing", func(t *testing.T) {
+		tm := newTestModel(t,
+			WithLines([]string{"line 1", "line 2"}),
+			WithCursorPos(action.Position{Line: 0, Col: 0}),
+			WithRegister('"', action.LinewiseRegister, []string{}),
+		)
+		sendKeys(tm, "P")
+
+		m := getFinalModel(t, tm)
+		if m.LineCount() != 2 {
+			t.Errorf("LineCount() = %d, want 2", m.LineCount())
+		}
+	})
+
+	t.Run("P preserves indentation in pasted lines", func(t *testing.T) {
+		tm := newTestModel(t,
+			WithLines([]string{"line 1"}),
+			WithCursorPos(action.Position{Line: 0, Col: 0}),
+			WithRegister('"', action.LinewiseRegister, []string{"    indented", "\ttabbed"}),
+		)
+		sendKeys(tm, "P")
+
+		m := getFinalModel(t, tm)
+		if m.Line(0) != "    indented" {
+			t.Errorf("Line(0) = %q, want '    indented'", m.Line(0))
+		}
+		if m.Line(1) != "\ttabbed" {
+			t.Errorf("Line(1) = %q, want '\\ttabbed'", m.Line(1))
+		}
+	})
+
+	t.Run("P with large count", func(t *testing.T) {
+		tm := newTestModel(t,
+			WithLines([]string{"original"}),
+			WithCursorPos(action.Position{Line: 0, Col: 0}),
+			WithRegister('"', action.LinewiseRegister, []string{"x"}),
+		)
+		sendKeys(tm, "1", "0", "P") // 10P
+
+		m := getFinalModel(t, tm)
+		if m.LineCount() != 11 {
+			t.Errorf("LineCount() = %d, want 11", m.LineCount())
+		}
+		// Original should be at the end
+		if m.Line(10) != "original" {
+			t.Errorf("Line(10) = %q, want 'original'", m.Line(10))
+		}
+	})
+}
+
+func TestPasteLinewiseEdgeCases(t *testing.T) {
+	t.Run("p on single line buffer", func(t *testing.T) {
+		tm := newTestModel(t,
+			WithLines([]string{"only line"}),
+			WithCursorPos(action.Position{Line: 0, Col: 0}),
+			WithRegister('"', action.LinewiseRegister, []string{"inserted"}),
+		)
+		sendKeys(tm, "p")
+
+		m := getFinalModel(t, tm)
+		if m.LineCount() != 2 {
+			t.Errorf("LineCount() = %d, want 2", m.LineCount())
+		}
+		if m.Line(0) != "only line" {
+			t.Errorf("Line(0) = %q, want 'only line'", m.Line(0))
+		}
+		if m.Line(1) != "inserted" {
+			t.Errorf("Line(1) = %q, want 'inserted'", m.Line(1))
+		}
+	})
+
+	t.Run("p with empty register content does nothing", func(t *testing.T) {
+		tm := newTestModel(t,
+			WithLines([]string{"line 1", "line 2"}),
+			WithCursorPos(action.Position{Line: 0, Col: 0}),
+			WithRegister('"', action.LinewiseRegister, []string{}),
+		)
+		sendKeys(tm, "p")
+
+		m := getFinalModel(t, tm)
+		if m.LineCount() != 2 {
+			t.Errorf("LineCount() = %d, want 2", m.LineCount())
+		}
+	})
+
+	t.Run("p preserves indentation in pasted lines", func(t *testing.T) {
+		tm := newTestModel(t,
+			WithLines([]string{"line 1"}),
+			WithCursorPos(action.Position{Line: 0, Col: 0}),
+			WithRegister('"', action.LinewiseRegister, []string{"    indented", "\ttabbed"}),
+		)
+		sendKeys(tm, "p")
+
+		m := getFinalModel(t, tm)
+		if m.Line(1) != "    indented" {
+			t.Errorf("Line(1) = %q, want '    indented'", m.Line(1))
+		}
+		if m.Line(2) != "\ttabbed" {
+			t.Errorf("Line(2) = %q, want '\\ttabbed'", m.Line(2))
+		}
+	})
+
+	t.Run("p with large count", func(t *testing.T) {
+		tm := newTestModel(t,
+			WithLines([]string{"original"}),
+			WithCursorPos(action.Position{Line: 0, Col: 0}),
+			WithRegister('"', action.LinewiseRegister, []string{"x"}),
+		)
+		sendKeys(tm, "1", "0", "p") // 10p
+
+		m := getFinalModel(t, tm)
+		if m.LineCount() != 11 {
+			t.Errorf("LineCount() = %d, want 11", m.LineCount())
+		}
+	})
+}

internal/editor/integration_scroll_test.go

@@ -87,11 +87,10 @@ func TestScrollBasic(t *testing.T) {
 		if m.CursorY() != 99 {
 			t.Errorf("CursorY() = %d, want 99", m.CursorY())
 		}
-		// With 100 lines and viewport 19, max scrollY = 100 - 19 = 81
+		// With 100 lines and viewport 18 (height - 2 for status + command bar),
-		// Cursor at 99 with scrollOff=8 means cursor at position 10 from top
+		// max scrollY = 100 - 18 = 82
-		// scrollY = 99 - 10 = 89, but clamped to maxScroll = 81
+		if m.ScrollY() != 82 {
-		if m.ScrollY() != 81 {
+			t.Errorf("ScrollY() = %d, want 82", m.ScrollY())
-			t.Errorf("ScrollY() = %d, want 81", m.ScrollY())
 		}
 	})
 
@@ -132,8 +131,8 @@ func TestScrollEdgeCases(t *testing.T) {
 		sendKeys(tm, "G")
 
 		m := getFinalModel(t, tm)
-		// 30 lines, viewport 19 -> maxScroll = 30 - 19 = 11
+		// 30 lines, viewport 18 (height - 2) -> maxScroll = 30 - 18 = 12
-		maxScroll := 30 - 19
+		maxScroll := 30 - 18
 		if m.ScrollY() > maxScroll {
 			t.Errorf("ScrollY() = %d, want <= %d", m.ScrollY(), maxScroll)
 		}
@@ -156,6 +155,263 @@ func TestScrollEdgeCases(t *testing.T) {
 	})
 }
 
+// Tests use terminal 80x30: viewportH=28, half-scroll=14, scrollOff=8, safe zone relY 8-19.
+
+func TestHalfPageScrollDown(t *testing.T) {
+	t.Run("ctrl+d scrolls viewport down by half", func(t *testing.T) {
+		// cursor at line 15 (relY=15, in safe zone), scrollY starts at 0
+		// After ctrl+d: newScrollY=14, newCursorY=14+15=29
+		lines := generateLines(100)
+		tm := newTestModelWithTermSize(t, lines, action.Position{Col: 0, Line: 15}, 80, 30)
+		sendKeys(tm, "ctrl+d")
+
+		m := getFinalModel(t, tm)
+		if m.ScrollY() != 14 {
+			t.Errorf("ScrollY() = %d, want 14", m.ScrollY())
+		}
+		if m.CursorY() != 29 {
+			t.Errorf("CursorY() = %d, want 29", m.CursorY())
+		}
+	})
+
+	t.Run("ctrl+d preserves cursor relative position in viewport", func(t *testing.T) {
+		// relY=15 before and after
+		lines := generateLines(100)
+		tm := newTestModelWithTermSize(t, lines, action.Position{Col: 0, Line: 15}, 80, 30)
+		sendKeys(tm, "ctrl+d")
+
+		m := getFinalModel(t, tm)
+		relY := m.CursorY() - m.ScrollY()
+		if relY != 15 {
+			t.Errorf("relative position = %d, want 15", relY)
+		}
+	})
+
+	t.Run("ctrl+d clamps cursor to scrollOff when cursor is near top", func(t *testing.T) {
+		// cursor at line 0 (relY=0 < scrollOff=8), clamp to scrollOff
+		// After ctrl+d: newScrollY=14, newCursorY=14+8=22
+		lines := generateLines(100)
+		tm := newTestModelWithTermSize(t, lines, action.Position{Col: 0, Line: 0}, 80, 30)
+		sendKeys(tm, "ctrl+d")
+
+		m := getFinalModel(t, tm)
+		if m.ScrollY() != 14 {
+			t.Errorf("ScrollY() = %d, want 14", m.ScrollY())
+		}
+		if m.CursorY() != 22 {
+			t.Errorf("CursorY() = %d, want 22", m.CursorY())
+		}
+	})
+
+	t.Run("ctrl+d at end of file does not scroll past max", func(t *testing.T) {
+		// 40 lines, viewport 28: maxScroll=12
+		// AdjustScroll puts cursor 35 at scrollY=12 (clamped), relY=23
+		// After ctrl+d: newScrollY clamped to 12, relY=23>19 clamped to 19, newCursorY=31
+		lines := generateLines(40)
+		tm := newTestModelWithTermSize(t, lines, action.Position{Col: 0, Line: 35}, 80, 30)
+		sendKeys(tm, "ctrl+d")
+
+		m := getFinalModel(t, tm)
+		maxScroll := 40 - 28
+		if m.ScrollY() > maxScroll {
+			t.Errorf("ScrollY() = %d, want <= %d", m.ScrollY(), maxScroll)
+		}
+		if m.CursorY() != 31 {
+			t.Errorf("CursorY() = %d, want 31", m.CursorY())
+		}
+	})
+
+	t.Run("ctrl+d on file smaller than viewport does not crash", func(t *testing.T) {
+		// 20 lines < viewport 28: maxScroll=0, scrollY stays 0
+		// relY=0 < scrollOff, clamp to 8; newCursorY=0+8=8
+		lines := generateLines(20)
+		tm := newTestModelWithTermSize(t, lines, action.Position{Col: 0, Line: 0}, 80, 30)
+		sendKeys(tm, "ctrl+d")
+
+		m := getFinalModel(t, tm)
+		if m.ScrollY() != 0 {
+			t.Errorf("ScrollY() = %d, want 0", m.ScrollY())
+		}
+		if m.CursorY() != 8 {
+			t.Errorf("CursorY() = %d, want 8", m.CursorY())
+		}
+	})
+
+	t.Run("ctrl+d clamps cursor x to new line length", func(t *testing.T) {
+		// Lines 0-14: "hello world" (11 chars), lines 15-99: "hi" (2 chars)
+		// cursor at line 5, cursorX=10
+		// ctrl+d: relY=5<8 clamp to 8; newScrollY=14; newCursorY=22 (a "hi" line)
+		// ClampCursorX: 10 >= 2, so cursorX=2
+		lines := make([]string, 100)
+		for i := range 15 {
+			lines[i] = "hello world"
+		}
+		for i := 15; i < 100; i++ {
+			lines[i] = "hi"
+		}
+		tm := newTestModelWithTermSize(t, lines, action.Position{Col: 10, Line: 5}, 80, 30)
+		sendKeys(tm, "ctrl+d")
+
+		m := getFinalModel(t, tm)
+		if m.CursorY() != 22 {
+			t.Errorf("CursorY() = %d, want 22", m.CursorY())
+		}
+		if m.CursorX() > len(m.Line(m.CursorY())) {
+			t.Errorf("CursorX() = %d exceeds line length %d", m.CursorX(), len(m.Line(m.CursorY())))
+		}
+	})
+
+	t.Run("multiple ctrl+d presses scroll incrementally", func(t *testing.T) {
+		// cursor at line 15, scrollY=0, relY=15
+		// ctrl+d #1: scrollY=14, cursorY=29, relY=15
+		// ctrl+d #2: scrollY=28, cursorY=43, relY=15
+		lines := generateLines(200)
+		tm := newTestModelWithTermSize(t, lines, action.Position{Col: 0, Line: 15}, 80, 30)
+		sendKeys(tm, "ctrl+d", "ctrl+d")
+
+		m := getFinalModel(t, tm)
+		if m.ScrollY() != 28 {
+			t.Errorf("ScrollY() = %d, want 28", m.ScrollY())
+		}
+		if m.CursorY() != 43 {
+			t.Errorf("CursorY() = %d, want 43", m.CursorY())
+		}
+	})
+}
+
+func TestHalfPageScrollUp(t *testing.T) {
+	t.Run("ctrl+u scrolls viewport up by half", func(t *testing.T) {
+		// cursor at line 50: AdjustScroll -> scrollY=31, relY=19
+		// After ctrl+u: newScrollY=17, newCursorY=17+19=36
+		lines := generateLines(100)
+		tm := newTestModelWithTermSize(t, lines, action.Position{Col: 0, Line: 50}, 80, 30)
+		sendKeys(tm, "ctrl+u")
+
+		m := getFinalModel(t, tm)
+		if m.ScrollY() != 17 {
+			t.Errorf("ScrollY() = %d, want 17", m.ScrollY())
+		}
+		if m.CursorY() != 36 {
+			t.Errorf("CursorY() = %d, want 36", m.CursorY())
+		}
+	})
+
+	t.Run("ctrl+u preserves cursor relative position in viewport", func(t *testing.T) {
+		// relY=19 before and after
+		lines := generateLines(100)
+		tm := newTestModelWithTermSize(t, lines, action.Position{Col: 0, Line: 50}, 80, 30)
+		sendKeys(tm, "ctrl+u")
+
+		m := getFinalModel(t, tm)
+		relY := m.CursorY() - m.ScrollY()
+		if relY != 19 {
+			t.Errorf("relative position = %d, want 19", relY)
+		}
+	})
+
+	t.Run("ctrl+u at top of file does not make scrollY negative", func(t *testing.T) {
+		// cursor at line 10, scrollY=0, relY=10 (in safe zone)
+		// ctrl+u: newScrollY=max(0,-14)=0, relY=10 preserved, cursorY=10
+		lines := generateLines(100)
+		tm := newTestModelWithTermSize(t, lines, action.Position{Col: 0, Line: 10}, 80, 30)
+		sendKeys(tm, "ctrl+u")
+
+		m := getFinalModel(t, tm)
+		if m.ScrollY() < 0 {
+			t.Errorf("ScrollY() = %d, want >= 0", m.ScrollY())
+		}
+		if m.ScrollY() != 0 {
+			t.Errorf("ScrollY() = %d, want 0", m.ScrollY())
+		}
+		if m.CursorY() != 10 {
+			t.Errorf("CursorY() = %d, want 10", m.CursorY())
+		}
+	})
+
+	t.Run("ctrl+u clamps cursor to scrollOff when cursor is near top of viewport", func(t *testing.T) {
+		// cursor at line 5, scrollY=0, relY=5 < scrollOff=8
+		// ctrl+u: newScrollY=0; relY clamp to 8; newCursorY=8
+		lines := generateLines(100)
+		tm := newTestModelWithTermSize(t, lines, action.Position{Col: 0, Line: 5}, 80, 30)
+		sendKeys(tm, "ctrl+u")
+
+		m := getFinalModel(t, tm)
+		if m.ScrollY() != 0 {
+			t.Errorf("ScrollY() = %d, want 0", m.ScrollY())
+		}
+		if m.CursorY() != 8 {
+			t.Errorf("CursorY() = %d, want 8", m.CursorY())
+		}
+	})
+
+	t.Run("multiple ctrl+u presses scroll incrementally", func(t *testing.T) {
+		// cursor at line 80: AdjustScroll -> scrollY=61, relY=19
+		// ctrl+u #1: newScrollY=47, cursorY=66
+		// ctrl+u #2: newScrollY=33, cursorY=52
+		lines := generateLines(200)
+		tm := newTestModelWithTermSize(t, lines, action.Position{Col: 0, Line: 80}, 80, 30)
+		sendKeys(tm, "ctrl+u", "ctrl+u")
+
+		m := getFinalModel(t, tm)
+		if m.ScrollY() != 33 {
+			t.Errorf("ScrollY() = %d, want 33", m.ScrollY())
+		}
+		if m.CursorY() != 52 {
+			t.Errorf("CursorY() = %d, want 52", m.CursorY())
+		}
+	})
+}
+
+func TestHalfPageScrollRoundTrip(t *testing.T) {
+	t.Run("ctrl+d then ctrl+u returns cursor to original position", func(t *testing.T) {
+		// cursor at line 15, scrollY=0, relY=15
+		// ctrl+d: scrollY=14, cursorY=29, relY=15
+		// ctrl+u: newScrollY=max(0,14-14)=0, cursorY=0+15=15
+		lines := generateLines(200)
+		tm := newTestModelWithTermSize(t, lines, action.Position{Col: 0, Line: 15}, 80, 30)
+		sendKeys(tm, "ctrl+d", "ctrl+u")
+
+		m := getFinalModel(t, tm)
+		if m.ScrollY() != 0 {
+			t.Errorf("ScrollY() = %d, want 0", m.ScrollY())
+		}
+		if m.CursorY() != 15 {
+			t.Errorf("CursorY() = %d, want 15", m.CursorY())
+		}
+	})
+
+	t.Run("ctrl+u then ctrl+d returns cursor to original position", func(t *testing.T) {
+		// cursor at line 50: AdjustScroll -> scrollY=31, relY=19
+		// ctrl+u: scrollY=17, cursorY=36, relY=19
+		// ctrl+d: scrollY=31, cursorY=50, relY=19
+		lines := generateLines(200)
+		tm := newTestModelWithTermSize(t, lines, action.Position{Col: 0, Line: 50}, 80, 30)
+		sendKeys(tm, "ctrl+u", "ctrl+d")
+
+		m := getFinalModel(t, tm)
+		if m.ScrollY() != 31 {
+			t.Errorf("ScrollY() = %d, want 31", m.ScrollY())
+		}
+		if m.CursorY() != 50 {
+			t.Errorf("CursorY() = %d, want 50", m.CursorY())
+		}
+	})
+
+	t.Run("alternating ctrl+d and ctrl+u maintains scroll stability", func(t *testing.T) {
+		lines := generateLines(200)
+		tm := newTestModelWithTermSize(t, lines, action.Position{Col: 0, Line: 15}, 80, 30)
+		sendKeys(tm, "ctrl+d", "ctrl+u", "ctrl+d", "ctrl+u")
+
+		m := getFinalModel(t, tm)
+		if m.ScrollY() != 0 {
+			t.Errorf("ScrollY() = %d, want 0 after 2 round trips", m.ScrollY())
+		}
+		if m.CursorY() != 15 {
+			t.Errorf("CursorY() = %d, want 15 after 2 round trips", m.CursorY())
+		}
+	})
+}
+
 func TestScrollWithCount(t *testing.T) {
 	t.Run("5j scrolls appropriately", func(t *testing.T) {
 		lines := generateLines(50)

internal/editor/model.go

@@ -1,6 +1,7 @@
 package editor
 
 import (
+	"fmt"
 	"strings"
 
 	"git.gophernest.net/azpect/TextEditor/internal/action"
@@ -36,6 +37,9 @@ type Model struct {
 
 	// Settings
 	settings action.Settings
+
+	// Registers
+	registers map[rune]action.Register // name -> register
 }
 
 func NewModel(lines []string, pos action.Position) Model {
@@ -50,6 +54,7 @@ func NewModel(lines []string, pos action.Position) Model {
 		command:   "",
 		input:     input.NewHandler(),
 		settings:  action.NewDefaultSettings(),
+		registers: action.DefaultRegisters(),
 	}
 }
 
@@ -186,6 +191,40 @@ func (m *Model) SetSettings(s action.Settings) {
 	m.settings = s
 }
 
+// Registers
+func (m *Model) Registers() map[rune]action.Register {
+	return m.registers
+}
+
+func (m *Model) GetRegister(name rune) (action.Register, bool) {
+	reg, found := m.registers[name]
+	return reg, found
+}
+
+func (m *Model) SetRegister(name rune, t action.RegisterType, cnt []string) error {
+	if _, found := m.GetRegister(name); !found {
+		return fmt.Errorf("Register '%c' does not exist.", name)
+	}
+
+	// TODO: This might be slow, pointers maybe?
+	reg := action.Register{Type: t, Content: cnt}
+	m.registers[name] = reg
+
+	return nil
+}
+
+// TODO: Errors?
+func (m *Model) UpdateDefault(t action.RegisterType, cnt []string) {
+	// Shift numbered registers: 0 -> 1 -> 2 -> ... -> 9 -> _ (discarded)
+	for i := rune('9'); i > '0'; i-- {
+		m.registers[i] = m.registers[i-1]
+	}
+
+	// 0 and " both hold the new content independently
+	m.SetRegister('0', t, cnt)
+	m.SetRegister('"', t, cnt)
+}
+
 // Window
 func (m *Model) ScrollY() int {
 	return m.scrollY
@@ -195,6 +234,18 @@ func (m *Model) SetScrollY(y int) {
 	m.scrollY = y
 }
 
+func (m *Model) WinH() int {
+	return m.win_h
+}
+
+func (m *Model) WinW() int {
+	return m.win_w
+}
+
+func (m *Model) ViewPortH() int {
+	return m.win_h - 2 // -2 for status bar and commmand bar
+}
+
 func (m *Model) ClampCursorX() {
 	lineLen := len(m.lines[m.cursor.y])
 	if lineLen == 0 {
@@ -207,7 +258,7 @@ func (m *Model) ClampCursorX() {
 // AdjustScroll ensures the cursor stays within the viewport with scrollOff margins.
 // Call this after any cursor movement.
 func (m *Model) AdjustScroll() {
-	viewportHeight := m.win_h - 1 // -1 for status bar
+	viewportHeight := m.ViewPortH()
 	if viewportHeight <= 0 {
 		return
 	}

internal/editor/update.go

@@ -14,6 +14,11 @@ func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 		m.win_w = msg.Width
 
 	case tea.KeyMsg:
+		// TODO: This needs to be removed, but for now its required for the tests.
+		// Ctrl+C always quits regardless of mode
+		if msg.Type == tea.KeyCtrlC {
+			return m, tea.Quit
+		}
 		cmd = m.input.Handle(&m, msg.String())
 	}
 

internal/editor/view.go

@@ -59,7 +59,7 @@ func posIsAnchor(m Model, col, line int) bool {
 func (m Model) View() string {
 	var view strings.Builder
 
-	viewportHeight := m.win_h - 2 // -2 for status bar and command bar
+	viewportHeight := m.ViewPortH()
 	start := m.ScrollY()
 	end := m.ScrollY() + viewportHeight
 

internal/input/handler.go

@@ -146,8 +146,8 @@ func (h *Handler) handleInitial(m action.Model, kind string, binding any, key st
 		// In visual mode, the selection is already defined — operate immediately
 		if m.Mode().IsVisualMode() {
 			start, end := normalizeVisualSelection(m)
-			// Visual line mode is linewise, others are charwise
+			// Visual line mode is linewise, others are charwise inclusive
-			mtype := action.Charwise
+			mtype := action.CharwiseInclusive
 			if m.Mode() == action.VisualLineMode {
 				mtype = action.Linewise
 			}
@@ -181,10 +181,15 @@ func (h *Handler) handleAfterOperator(m action.Model, kind string, binding any,
 
 	// dd, yy, cc - same operator key pressed twice
 	if kind == "operator" && key == h.operatorKey {
-		cmd := h.operator.DoublePress(m, count)
+		// Only call DoublePress if the operator supports it
+		if dp, ok := h.operator.(action.DoublePresser); ok {
+			cmd := dp.DoublePress(m, count)
 			h.Reset()
 			return cmd
 		}
+		h.Reset()
+		return nil
+	}
 
 	// Motion after operator
 	if kind == "motion" {

internal/input/keymap.go

@@ -28,12 +28,13 @@ func NewNormalKeymap() *Keymap {
 			"w":      motion.MoveForwardWord{Count: 1},
 			"e":      motion.MoveForwardWordEnd{Count: 1},
 			"b":      motion.MoveBackwardWord{Count: 1},
+			"ctrl+u": motion.ScrollUpHalfPage{},
+			"ctrl+d": motion.ScrollDownHalfPage{},
 		},
 		operators: map[string]action.Operator{
 			"d": operator.DeleteOperator{},
+			"y": operator.YankOperator{},
 			// "c": ChangeOp{},
-			// "y": YankOp{},
-			// "p": PasteOp{},
 			// "s": SubstitueOp{},
 			// "~": SwapCaseOp{},
 		},
@@ -45,11 +46,13 @@ func NewNormalKeymap() *Keymap {
 			"o":      action.OpenLineBelow{},
 			"O":      action.OpenLineAbove{},
 			"x":      action.DeleteChar{Count: 1},
-			"ctrl+c": action.Quit{},
 			":":      action.EnterComandMode{},
 			"v":      action.EnterVisualMode{},
 			"V":      action.EnterVisualLineMode{},
 			"ctrl+v": action.EnterVisualBlockMode{},
+			"D":      action.DeleteToEndOfLine{Count: 1},
+			"p":      action.Paste{Count: 1},
+			"P":      action.PasteBefore{Count: 1},
 		},
 	}
 }
@@ -73,6 +76,7 @@ func NewVisualKeymap() *Keymap {
 		operators: map[string]action.Operator{
 			"d": operator.DeleteOperator{},
 			"x": operator.DeleteOperator{},
+			"y": operator.YankOperator{},
 			// "c": ChangeOp{},
 			// "y": YankOp{},
 			// "p": PasteOp{},
@@ -80,7 +84,6 @@ func NewVisualKeymap() *Keymap {
 			// "~": SwapCaseOp{},
 		},
 		actions: map[string]action.Action{
-			"ctrl+c": action.Quit{},
 			// ":":      action.EnterComandMode{}, // Different OP
 		},
 	}
@@ -101,7 +104,6 @@ func NewInsertKeymap() *Keymap {
 			"delete":    action.InsertDelete{},
 			"tab":       action.InsertTab{},
 			"ctrl+w":    action.InsertDeletePreviousWord{},
-			"ctrl+c":    action.Quit{},
 		},
 	}
 

internal/motion/basic.go

@@ -56,7 +56,7 @@ func (a MoveLeft) Execute(m action.Model) tea.Cmd {
 	return nil
 }
 
-func (a MoveLeft) Type() action.MotionType { return action.Charwise }
+func (a MoveLeft) Type() action.MotionType { return action.CharwiseExclusive }
 
 func (a MoveLeft) WithCount(n int) action.Action {
 	return MoveLeft{Count: n}
@@ -76,7 +76,7 @@ func (a MoveRight) Execute(m action.Model) tea.Cmd {
 	return nil
 }
 
-func (a MoveRight) Type() action.MotionType { return action.Charwise }
+func (a MoveRight) Type() action.MotionType { return action.CharwiseExclusive }
 
 func (a MoveRight) WithCount(n int) action.Action {
 	return MoveRight{Count: n}

internal/motion/command.go

@@ -13,7 +13,7 @@ func (a MoveCommandLeft) Execute(m action.Model) tea.Cmd {
 	return nil
 }
 
-func (a MoveCommandLeft) Type() action.MotionType { return action.Charwise }
+func (a MoveCommandLeft) Type() action.MotionType { return action.CharwiseExclusive }
 
 type MoveCommandRight struct{}
 
@@ -23,4 +23,4 @@ func (a MoveCommandRight) Execute(m action.Model) tea.Cmd {
 	return nil
 }
 
-func (a MoveCommandRight) Type() action.MotionType { return action.Charwise }
+func (a MoveCommandRight) Type() action.MotionType { return action.CharwiseExclusive }

internal/motion/jump.go

@@ -36,7 +36,7 @@ func (a MoveToLineStart) Execute(m action.Model) tea.Cmd {
 	return nil
 }
 
-func (a MoveToLineStart) Type() action.MotionType { return action.Charwise }
+func (a MoveToLineStart) Type() action.MotionType { return action.CharwiseExclusive }
 
 // MoveToLineEnd implements Motion ($) - charwise
 type MoveToLineEnd struct{}
@@ -47,7 +47,7 @@ func (a MoveToLineEnd) Execute(m action.Model) tea.Cmd {
 	return nil
 }
 
-func (a MoveToLineEnd) Type() action.MotionType { return action.Charwise }
+func (a MoveToLineEnd) Type() action.MotionType { return action.CharwiseInclusive }
 
 // MoveToLineContentStart implements Motion (_) - charwise
 type MoveToLineContentStart struct{}
@@ -72,4 +72,82 @@ func (a MoveToLineContentStart) Execute(m action.Model) tea.Cmd {
 	return nil
 }
 
-func (a MoveToLineContentStart) Type() action.MotionType { return action.Charwise }
+func (a MoveToLineContentStart) Type() action.MotionType { return action.CharwiseExclusive }
+
+// TODO: Count for these, maybe?
+
+// ScrollDownHalfPage implements Motion (ctrl+d) - linewise
+type ScrollDownHalfPage struct{}
+
+func (a ScrollDownHalfPage) Execute(m action.Model) tea.Cmd {
+	viewportHeight := m.ViewPortH()
+	if viewportHeight <= 0 {
+		return nil
+	}
+
+	scroll := viewportHeight / 2
+	scrollOff := m.Settings().ScrollOff
+
+	// Current relative position in viewport
+	relY := m.CursorY() - m.ScrollY()
+
+	// Scroll down, clamped to valid range
+	newScrollY := m.ScrollY() + scroll
+	maxScroll := max(0, m.LineCount()-viewportHeight)
+	newScrollY = min(newScrollY, maxScroll)
+	m.SetScrollY(newScrollY)
+
+	// Maintain relative position, respecting scrollOff
+	if relY < scrollOff {
+		relY = scrollOff
+	}
+	if relY > viewportHeight-1-scrollOff {
+		relY = viewportHeight - 1 - scrollOff
+	}
+
+	newCursorY := newScrollY + relY
+	newCursorY = max(0, min(newCursorY, m.LineCount()-1))
+	m.SetCursorY(newCursorY)
+	m.ClampCursorX()
+
+	return nil
+}
+
+func (a ScrollDownHalfPage) Type() action.MotionType { return action.Linewise }
+
+// ScrollUpHalfPage implements Motion (ctrl+u) - linewise
+type ScrollUpHalfPage struct{}
+
+func (a ScrollUpHalfPage) Execute(m action.Model) tea.Cmd {
+	viewportHeight := m.ViewPortH()
+	if viewportHeight <= 0 {
+		return nil
+	}
+	scroll := viewportHeight / 2
+	scrollOff := m.Settings().ScrollOff
+
+	// Current relative position in viewport
+	relY := m.CursorY() - m.ScrollY()
+
+	// Scroll up, clamped to valid range
+	newScrollY := m.ScrollY() - scroll
+	newScrollY = max(0, newScrollY)
+	m.SetScrollY(newScrollY)
+
+	// Maintain relative position, respecting scrollOff
+	if relY < scrollOff {
+		relY = scrollOff
+	}
+	if relY > viewportHeight-1-scrollOff {
+		relY = viewportHeight - 1 - scrollOff
+	}
+
+	newCursorY := newScrollY + relY
+	newCursorY = max(0, min(newCursorY, m.LineCount()-1))
+	m.SetCursorY(newCursorY)
+	m.ClampCursorX()
+
+	return nil
+}
+
+func (a ScrollUpHalfPage) Type() action.MotionType { return action.Linewise }

internal/motion/word.go

@@ -187,7 +187,7 @@ func (a MoveForwardWord) Execute(m action.Model) tea.Cmd {
 	return nil
 }
 
-func (a MoveForwardWord) Type() action.MotionType { return action.Charwise }
+func (a MoveForwardWord) Type() action.MotionType { return action.CharwiseExclusive }
 
 func (a MoveForwardWord) WithCount(n int) action.Action {
 	return MoveForwardWord{Count: n}
@@ -209,7 +209,7 @@ func (a MoveForwardWordEnd) Execute(m action.Model) tea.Cmd {
 	return nil
 }
 
-func (a MoveForwardWordEnd) Type() action.MotionType { return action.Charwise }
+func (a MoveForwardWordEnd) Type() action.MotionType { return action.CharwiseInclusive }
 
 func (a MoveForwardWordEnd) WithCount(n int) action.Action {
 	return MoveForwardWordEnd{Count: n}
@@ -231,7 +231,7 @@ func (a MoveBackwardWord) Execute(m action.Model) tea.Cmd {
 	return nil
 }
 
-func (a MoveBackwardWord) Type() action.MotionType { return action.Charwise }
+func (a MoveBackwardWord) Type() action.MotionType { return action.CharwiseExclusive }
 
 func (a MoveBackwardWord) WithCount(n int) action.Action {
 	return MoveBackwardWord{Count: n}

internal/operator/delete.go

@@ -22,13 +22,20 @@ func (o DeleteOperator) Operate(m action.Model, start, end action.Position, mtyp
 	return nil
 }
 
+// Verify DeleteOperator implements DoublePresser
+var _ action.DoublePresser = DeleteOperator{}
+
 // Double press handles dd - delete the entire line
 func (o DeleteOperator) DoublePress(m action.Model, count int) tea.Cmd {
 	// If we have a higher value than lines remaining, we can only run so many times
 	opCount := min(count, m.LineCount()-m.CursorY())
 
+	var lines []string
+
 	for range opCount {
 		y := m.CursorY()
+		lines = append(lines, m.Line(y))
+
 		m.DeleteLine(y)
 
 		if m.LineCount() == 0 {
@@ -43,6 +50,10 @@ func (o DeleteOperator) DoublePress(m action.Model, count int) tea.Cmd {
 		m.ClampCursorX()
 	}
 
+	// Put her in the register!
+	m.UpdateDefault(action.LinewiseRegister, lines)
+	// m.SetRegister('"', action.LinewiseRegister, lines)
+
 	return nil
 }
 
@@ -61,11 +72,13 @@ func deleteNormalMode(m action.Model, start, end action.Position, mtype action.M
 	// Charwise motions on same line
 	if start.Line == end.Line {
 		// No movement = nothing to delete
-		if start.Col == end.Col {
+		if start.Col == end.Col && mtype == action.CharwiseExclusive {
 			return
 		}
-		// Exclusive motion: delete [start.Col, end.Col)
+		// Exclusive motion: end position not included, so back up one
+		if mtype == action.CharwiseExclusive {
 			end.Col--
+		}
 		if end.Col >= start.Col {
 			deleteCharSelection(m, start, end)
 		}
@@ -104,7 +117,10 @@ func deleteCharSelection(m action.Model, start, end action.Position) {
 }
 
 func deleteLineSelection(m action.Model, start, end action.Position) {
+	var lines []string
+
 	for i := end.Line; i >= start.Line; i-- {
+		lines = append(lines, m.Line(i))
 		m.DeleteLine(i)
 	}
 
@@ -119,6 +135,9 @@ func deleteLineSelection(m action.Model, start, end action.Position) {
 
 	m.SetCursorY(y)
 	m.ClampCursorX()
+
+	// Update registers
+	m.UpdateDefault(action.LinewiseRegister, lines)
 }
 
 func deleteBlockSelection(m action.Model, start, end action.Position) {

internal/operator/yank.go

@@ -0,0 +1,169 @@
+package operator
+
+import (
+	"fmt"
+
+	"git.gophernest.net/azpect/TextEditor/internal/action"
+	tea "github.com/charmbracelet/bubbletea"
+)
+
+// Implements Operator (y)
+type YankOperator struct{}
+
+func (o YankOperator) Operate(m action.Model, start, end action.Position, mtype action.MotionType) tea.Cmd {
+	switch m.Mode() {
+	case action.VisualMode:
+		yankVisualMode(m, start, end)
+	case action.VisualLineMode:
+		yankVisualLineMode(m, start, end)
+	case action.VisualBlockMode:
+		yankVisualBlockMode(m, start, end)
+	case action.NormalMode:
+		yankNormalMode(m, start, end, mtype)
+	default:
+		m.SetCommandError(fmt.Errorf("'y' operator not yet implemented."))
+	}
+
+	m.SetCursorX(start.Col)
+	m.SetCursorY(start.Line)
+	return nil
+}
+
+// Verify YankOperator implements DoublePresser
+var _ action.DoublePresser = YankOperator{}
+
+func (o YankOperator) DoublePress(m action.Model, count int) tea.Cmd {
+	y := m.CursorY()
+
+	// If we have a higher value than lines remaining, we can only run so many times
+	opCount := min(count, m.LineCount()-y)
+
+	var lines []string
+
+	for i := range opCount {
+		lines = append(lines, m.Line(y+i))
+	}
+
+	// Put her in the register!
+	m.UpdateDefault(action.LinewiseRegister, lines)
+
+	return nil
+}
+
+func yankNormalMode(m action.Model, start, end action.Position, mtype action.MotionType) {
+	switch {
+	case mtype.IsCharwise():
+		// This shouldn't happen
+		if start.Line != end.Line {
+			m.SetCommandError(fmt.Errorf("Start line and end line must match for charwise yank operations."))
+			return
+		}
+
+		line := m.Line(start.Line)
+
+		startX := min(start.Col, end.Col)
+		endX := max(start.Col, end.Col)
+
+		// Inclusive motions include the end character
+		if mtype == action.CharwiseInclusive {
+			endX++
+		}
+
+		endX = min(endX, len(line)) // Catch overflow
+
+		cnt := line[startX:endX]
+		m.UpdateDefault(action.CharwiseRegister, []string{cnt})
+
+	case mtype == action.Linewise:
+		// This shouldn't happen
+		if start.Col != end.Col {
+			m.SetCommandError(fmt.Errorf("Start column and end column must match for linewise yank operations."))
+			return
+		}
+
+		// These don't need to be validated, they are validated before being passed into the function
+		startY := min(start.Line, end.Line)
+		endY := max(start.Line, end.Line)
+
+		cnt := m.Lines()[startY : endY+1]
+		m.UpdateDefault(action.LinewiseRegister, cnt)
+	}
+}
+
+func yankVisualMode(m action.Model, start, end action.Position) {
+	// Normalize so start is before end
+	if start.Line > end.Line || (start.Line == end.Line && start.Col > end.Col) {
+		start, end = end, start
+	}
+
+	// Single line selection
+	if start.Line == end.Line {
+		line := m.Line(start.Line)
+		endCol := min(end.Col+1, len(line)) // +1 because visual selection is inclusive
+		startCol := min(start.Col, len(line))
+		cnt := line[startCol:endCol]
+		m.UpdateDefault(action.CharwiseRegister, []string{cnt})
+		return
+	}
+
+	// Multi-line selection
+	var content []string
+
+	// First line: from start.Col to end of line
+	firstLine := m.Line(start.Line)
+	startCol := min(start.Col, len(firstLine))
+	content = append(content, firstLine[startCol:])
+
+	// Middle lines: entire lines
+	for y := start.Line + 1; y < end.Line; y++ {
+		content = append(content, m.Line(y))
+	}
+
+	// Last line: from beginning to end.Col (inclusive)
+	lastLine := m.Line(end.Line)
+	endCol := min(end.Col+1, len(lastLine))
+	content = append(content, lastLine[:endCol])
+
+	m.UpdateDefault(action.CharwiseRegister, content)
+}
+
+func yankVisualLineMode(m action.Model, start, end action.Position) {
+	// This shouldn't happen
+	if start.Col != end.Col {
+		m.SetCommandError(fmt.Errorf("Start column and end column must match for linewise yank operations."))
+		return
+	}
+
+	// These don't need to be validated, they are validated before being passed into the function
+	startY := min(start.Line, end.Line)
+	endY := max(start.Line, end.Line)
+
+	cnt := m.Lines()[startY : endY+1]
+	m.UpdateDefault(action.LinewiseRegister, cnt)
+
+}
+
+func yankVisualBlockMode(m action.Model, start, end action.Position) {
+	// Normalize so startY <= endY and startX <= endX
+	startY := min(start.Line, end.Line)
+	endY := max(start.Line, end.Line)
+	startX := min(start.Col, end.Col)
+	endX := max(start.Col, end.Col) + 1 // +1 for inclusive
+
+	var content []string
+
+	for y := startY; y <= endY; y++ {
+		line := m.Line(y)
+
+		// Handle lines shorter than the block selection
+		if startX >= len(line) {
+			content = append(content, "")
+			continue
+		}
+
+		lineEndX := min(endX, len(line))
+		content = append(content, line[startX:lineEndX])
+	}
+
+	m.UpdateDefault(action.BlockwiseRegister, content)
+}