Introduce more strict numeric types for different kinds of indices

buffer.go

@@ -4,13 +4,14 @@ import (
  "strings"
 
  "github.com/elk-language/go-prompt/internal/debug"
+ istrings "github.com/elk-language/go-prompt/internal/strings"
 )
 
 // Buffer emulates the console buffer.
 type Buffer struct {
  workingLines []string // The working lines. Similar to history
- workingIndex int
- cursorPosition int
+ workingIndex int // index of the current line
+ cursorPosition istrings.RuneIndex
  cacheDocument *Document
  lastKeyStroke Key
 }
@@ -36,44 +37,43 @@ func (b *Buffer) Document() (d *Document) {
 
 // DisplayCursorPosition returns the cursor position on rendered text on terminal emulators.
 // So if Document is "日本(cursor)語", DisplayedCursorPosition returns 4 because '日' and '本' are double width characters.
-func (b *Buffer) DisplayCursorPosition(columns int) Position {
+func (b *Buffer) DisplayCursorPosition(columns istrings.StringWidth) Position {
  return b.Document().DisplayCursorPosition(columns)
 }
 
 // InsertText insert string from current line.
-func (b *Buffer) InsertText(v string, overwrite bool, moveCursor bool) {
- or := []rune(b.Text())
- oc := b.cursorPosition
+func (b *Buffer) InsertText(text string, overwrite bool, moveCursor bool) {
+ currentTextRunes := []rune(b.Text())
+ cursor := b.cursorPosition
 
  if overwrite {
- overwritten := string(or[oc:])
- if len(overwritten) >= oc+len(v) {
- overwritten = string(or[oc : oc+len(v)])
+ overwritten := string(currentTextRunes[cursor:])
+ if len(overwritten) >= int(cursor)+len(text) {
+ overwritten = string(currentTextRunes[cursor : cursor+istrings.RuneLen(text)])
  }
- if strings.Contains(overwritten, "\n") {
- i := strings.IndexAny(overwritten, "\n")
+ if i := strings.IndexAny(overwritten, "\n"); i != -1 {
  overwritten = overwritten[:i]
  }
- b.setText(string(or[:oc]) + v + string(or[oc+len(overwritten):]))
+ b.setText(string(currentTextRunes[:cursor]) + text + string(currentTextRunes[cursor+istrings.RuneLen(overwritten):]))
  } else {
- b.setText(string(or[:oc]) + v + string(or[oc:]))
+ b.setText(string(currentTextRunes[:cursor]) + text + string(currentTextRunes[cursor:]))
  }
 
  if moveCursor {
- b.cursorPosition += len([]rune(v))
+ b.cursorPosition += istrings.RuneLen(text)
  }
 }
 
 // SetText method to set text and update cursorPosition.
 // (When doing this, make sure that the cursor_position is valid for this text.
 // text/cursor_position should be consistent at any time, otherwise set a Document instead.)
-func (b *Buffer) setText(v string) {
- debug.Assert(b.cursorPosition <= len([]rune(v)), "length of input should be shorter than cursor position")
- b.workingLines[b.workingIndex] = v
+func (b *Buffer) setText(text string) {
+ debug.Assert(b.cursorPosition <= istrings.RuneLen(text), "length of input should be shorter than cursor position")
+ b.workingLines[b.workingIndex] = text
 }
 
 // Set cursor position. Return whether it changed.
-func (b *Buffer) setCursorPosition(p int) {
+func (b *Buffer) setCursorPosition(p istrings.RuneIndex) {
  if p > 0 {
  b.cursorPosition = p
  } else {
@@ -88,13 +88,13 @@ func (b *Buffer) setDocument(d *Document) {
 }
 
 // CursorLeft move to left on the current line.
-func (b *Buffer) CursorLeft(count int) {
+func (b *Buffer) CursorLeft(count istrings.RuneCount) {
  l := b.Document().GetCursorLeftPosition(count)
  b.cursorPosition += l
 }
 
 // CursorRight move to right on the current line.
-func (b *Buffer) CursorRight(count int) {
+func (b *Buffer) CursorRight(count istrings.RuneCount) {
  l := b.Document().GetCursorRightPosition(count)
  b.cursorPosition += l
 }
@@ -114,7 +114,7 @@ func (b *Buffer) CursorDown(count int) {
 }
 
 // DeleteBeforeCursor delete specified number of characters before cursor and return the deleted text.
-func (b *Buffer) DeleteBeforeCursor(count int) (deleted string) {
+func (b *Buffer) DeleteBeforeCursor(count istrings.RuneCount) (deleted string) {
  debug.Assert(count >= 0, "count should be positive")
  r := []rune(b.Text())
 
@@ -126,7 +126,7 @@ func (b *Buffer) DeleteBeforeCursor(count int) (deleted string) {
  deleted = string(r[start:b.cursorPosition])
  b.setDocument(&Document{
  Text: string(r[:start]) + string(r[b.cursorPosition:]),
- cursorPosition: b.cursorPosition - len([]rune(deleted)),
+ cursorPosition: b.cursorPosition - istrings.RuneIndex(len([]rune(deleted))),
  })
  }
  return
@@ -142,13 +142,19 @@ func (b *Buffer) NewLine(copyMargin bool) {
 }
 
 // Delete specified number of characters and Return the deleted text.
-func (b *Buffer) Delete(count int) (deleted string) {
+func (b *Buffer) Delete(count istrings.RuneCount) string {
  r := []rune(b.Text())
- if b.cursorPosition < len(r) {
- deleted = b.Document().TextAfterCursor()[:count]
- b.setText(string(r[:b.cursorPosition]) + string(r[b.cursorPosition+len(deleted):]))
+ if b.cursorPosition < istrings.RuneIndex(len(r)) {
+ textAfterCursor := b.Document().TextAfterCursor()
+ textAfterCursorRunes := []rune(textAfterCursor)
+ deletedRunes := textAfterCursorRunes[:count]
+ b.setText(string(r[:b.cursorPosition]) + string(r[b.cursorPosition+istrings.RuneCount(len(deletedRunes)):]))
+
+ deleted := string(deletedRunes)
+ return deleted
  }
- return
+
+ return ""
 }
 
 // JoinNextLine joins the next line to the current one by deleting the line ending after the current line.

buffer_test.go

@@ -3,6 +3,8 @@ package prompt
 import (
  "reflect"
  "testing"
+
+ istrings "github.com/elk-language/go-prompt/internal/strings"
 )
 
 func TestNewBuffer(t *testing.T) {
@@ -23,8 +25,8 @@ func TestBuffer_InsertText(t *testing.T) {
  t.Errorf("Text should be %#v, got %#v", "some_text", b.Text())
  }
 
- if b.cursorPosition != len("some_text") {
- t.Errorf("cursorPosition should be %#v, got %#v", len("some_text"), b.cursorPosition)
+ if b.cursorPosition != istrings.RuneLen("some_text") {
+ t.Errorf("cursorPosition should be %#v, got %#v", istrings.RuneLen("some_text"), b.cursorPosition)
  }
 }
 
@@ -36,8 +38,8 @@ func TestBuffer_InsertText_Overwrite(t *testing.T) {
  t.Errorf("Text should be %#v, got %#v", "ABC", b.Text())
  }
 
- if b.cursorPosition != len("ABC") {
- t.Errorf("cursorPosition should be %#v, got %#v", len("ABC"), b.cursorPosition)
+ if b.cursorPosition != istrings.RuneLen("ABC") {
+ t.Errorf("cursorPosition should be %#v, got %#v", istrings.RuneLen("ABC"), b.cursorPosition)
  }
 
  b.CursorLeft(1)
@@ -85,8 +87,8 @@ func TestBuffer_CursorMovement(t *testing.T) {
  if b.Text() != "some_teAxt" {
  t.Errorf("Text should be %#v, got %#v", "some_teAxt", b.Text())
  }
- if b.cursorPosition != len("some_teA") {
- t.Errorf("Text should be %#v, got %#v", len("some_teA"), b.cursorPosition)
+ if b.cursorPosition != istrings.RuneLen("some_teA") {
+ t.Errorf("Text should be %#v, got %#v", istrings.RuneLen("some_teA"), b.cursorPosition)
  }
 
  // Moving over left character counts.
@@ -95,8 +97,8 @@ func TestBuffer_CursorMovement(t *testing.T) {
  if b.Text() != "Asome_teAxt" {
  t.Errorf("Text should be %#v, got %#v", "some_teAxt", b.Text())
  }
- if b.cursorPosition != len("A") {
- t.Errorf("Text should be %#v, got %#v", len("some_teA"), b.cursorPosition)
+ if b.cursorPosition != istrings.RuneLen("A") {
+ t.Errorf("Text should be %#v, got %#v", istrings.RuneLen("some_teA"), b.cursorPosition)
  }
 
  // TODO: Going right already at right end.
@@ -109,6 +111,10 @@ func TestBuffer_CursorMovement_WithMultiByte(t *testing.T) {
  if l := b.Document().TextAfterCursor(); l != "お" {
  t.Errorf("Should be 'お', but got %s", l)
  }
+ b.InsertText("żółć", true, true)
+ if b.Text() != "あいうえżółć" {
+ t.Errorf("Text should be %#v, got %#v", "あいうえżółć", b.Text())
+ }
 }
 
 func TestBuffer_CursorUp(t *testing.T) {
@@ -141,17 +147,17 @@ func TestBuffer_CursorDown(t *testing.T) {
 
  // Normally going down
  b.CursorDown(1)
- if b.Document().cursorPosition != len("line1\nlin") {
- t.Errorf("Should be %#v, got %#v", len("line1\nlin"), b.Document().cursorPosition)
+ if b.Document().cursorPosition != istrings.RuneLen("line1\nlin") {
+ t.Errorf("Should be %#v, got %#v", istrings.RuneLen("line1\nlin"), b.Document().cursorPosition)
  }
 
  // Going down to a line that's storter.
  b = NewBuffer()
  b.InsertText("long line1\na\nb", false, true)
  b.cursorPosition = 3
  b.CursorDown(1)
- if b.Document().cursorPosition != len("long line1\na") {
- t.Errorf("Should be %#v, got %#v", len("long line1\na"), b.Document().cursorPosition)
+ if b.Document().cursorPosition != istrings.RuneLen("long line1\na") {
+ t.Errorf("Should be %#v, got %#v", istrings.RuneLen("long line1\na"), b.Document().cursorPosition)
  }
 }
 
@@ -167,8 +173,8 @@ func TestBuffer_DeleteBeforeCursor(t *testing.T) {
  if deleted != "e" {
  t.Errorf("Should be %#v, got %#v", deleted, "e")
  }
- if b.cursorPosition != len("some_t") {
- t.Errorf("Should be %#v, got %#v", len("some_t"), b.cursorPosition)
+ if b.cursorPosition != istrings.RuneLen("some_t") {
+ t.Errorf("Should be %#v, got %#v", istrings.RuneLen("some_t"), b.cursorPosition)
  }
 
  // Delete over the characters length before cursor.

completion.go

@@ -4,6 +4,7 @@ import (
  "strings"
 
  "github.com/elk-language/go-prompt/internal/debug"
+ istrings "github.com/elk-language/go-prompt/internal/strings"
  runewidth "github.com/mattn/go-runewidth"
 )
 
@@ -155,7 +156,7 @@ func formatTexts(o []string, max int, prefix, suffix string) (new []string, widt
  return n, lenPrefix + width + lenSuffix
 }
 
-func formatSuggestions(suggests []Suggest, max int) (new []Suggest, width int) {
+func formatSuggestions(suggests []Suggest, max int) (new []Suggest, width istrings.StringWidth) {
  num := len(suggests)
  new = make([]Suggest, num)
 
@@ -177,7 +178,7 @@ func formatSuggestions(suggests []Suggest, max int) (new []Suggest, width int) {
  for i := 0; i < num; i++ {
  new[i] = Suggest{Text: left[i], Description: right[i]}
  }
- return new, leftWidth + rightWidth
+ return new, istrings.StringWidth(leftWidth + rightWidth)
 }
 
 // Constructor option for CompletionManager.

completion_test.go

@@ -3,14 +3,16 @@ package prompt
 import (
  "reflect"
  "testing"
+
+ istrings "github.com/elk-language/go-prompt/internal/strings"
 )
 
 func TestFormatShortSuggestion(t *testing.T) {
  var scenarioTable = []struct {
  in []Suggest
  expected []Suggest
  max int
- exWidth int
+ exWidth istrings.StringWidth
  }{
  {
  in: []Suggest{
@@ -38,7 +40,7 @@ func TestFormatShortSuggestion(t *testing.T) {
  {Text: " coconut ", Description: " This is coconut. "},
  },
  max: 100,
- exWidth: len(" apple " + " This is apple. "),
+ exWidth: istrings.StringWidth(len(" apple " + " This is apple. ")),
  },
  {
  in: []Suggest{
@@ -82,7 +84,7 @@ func TestFormatShortSuggestion(t *testing.T) {
  {Text: " --include-extended-apis ", Description: " --------------... "},
  },
  max: 50,
- exWidth: len(" --include-extended-apis " + " ---------------..."),
+ exWidth: istrings.StringWidth(len(" --include-extended-apis " + " ---------------...")),
  },
  {
  in: []Suggest{
@@ -102,7 +104,7 @@ func TestFormatShortSuggestion(t *testing.T) {
  {Text: " --include-extended-apis ", Description: " If true, include definitions of new APIs via calls to the API server. [default true] "},
  },
  max: 500,
- exWidth: len(" --include-extended-apis " + " If true, include definitions of new APIs via calls to the API server. [default true] "),
+ exWidth: istrings.StringWidth(len(" --include-extended-apis " + " If true, include definitions of new APIs via calls to the API server. [default true] ")),
  },
  }