From 9eb067485dfd468e6442dcb902e6bbabe8eb74be Mon Sep 17 00:00:00 2001
From: Timothy Warren <twarren@nabancard.com>
Date: Fri, 6 Oct 2023 15:23:01 -0400
Subject: [PATCH] Highlight multiline comments

---
 editor/document/document.go | 21 ++++++++++++++++-----
 editor/document/row.go      | 29 ++++++++++++++++++++++-------
 editor/document/row_test.go |  8 ++++----
 justfile                    |  2 +-
 4 files changed, 43 insertions(+), 17 deletions(-)

diff --git a/editor/document/document.go b/editor/document/document.go
index 222c095..d4958cd 100644
--- a/editor/document/document.go
+++ b/editor/document/document.go
@@ -16,13 +16,11 @@ type Document struct {
 }
 
 func NewDocument() *Document {
-	var rows []*Row
-
 	return &Document{
 		false,
 		"",
 		nil,
-		rows,
+		[]*Row{},
 	}
 }
 
@@ -85,13 +83,15 @@ func (d *Document) GetRow(at int) *Row {
 }
 
 func (d *Document) AppendRow(s string) {
-	newRow := newRow(d, s)
+	at := d.RowCount()
+	newRow := newRow(at, d, s)
 	newRow.update()
 	d.rows = append(d.rows, newRow)
 
 	d.dirty = true
 }
 
+// InsertRow is the equivalent of editorInsertRow in kilo
 func (d *Document) InsertRow(at int, s string) {
 	if at < 0 || at > d.RowCount() {
 		return
@@ -105,9 +105,14 @@ func (d *Document) InsertRow(at int, s string) {
 
 	// Splice it back together
 	newRows = append(newRows, start...)
-	newRows = append(newRows, newRow(d, s))
+	newRows = append(newRows, newRow(at, d, s))
 	newRows = append(newRows, end...)
 
+	// Update indices
+	for j := at + 1; j <= len(newRows); j++ {
+		newRows[j].index += 1
+	}
+
 	d.rows = newRows
 	d.dirty = true
 }
@@ -163,6 +168,7 @@ func (d *Document) IsDirty() bool {
 	return d.dirty
 }
 
+// delRow is the equivalent of kilo's editorDelRow
 func (d *Document) delRow(at int) {
 	var newSlice []*Row
 
@@ -174,6 +180,11 @@ func (d *Document) delRow(at int) {
 	newSlice = append(newSlice, start...)
 	newSlice = append(newSlice, end...)
 
+	// Update indices
+	for j := at - 1; j <= len(newSlice); j++ {
+		newSlice[j].index -= 1
+	}
+
 	d.rows = newSlice
 	d.dirty = true
 }
diff --git a/editor/document/row.go b/editor/document/row.go
index 097b318..dce2b08 100644
--- a/editor/document/row.go
+++ b/editor/document/row.go
@@ -8,13 +8,15 @@ import (
 )
 
 type Row struct {
-	parent *Document
-	chars  []rune
-	render []rune
-	Hl     []int
+	index         int
+	parent        *Document
+	chars         []rune
+	render        []rune
+	Hl            []int
+	startsComment bool
 }
 
-func newRow(parent *Document, s string) *Row {
+func newRow(at int, parent *Document, s string) *Row {
 	var chars []rune
 	var render []rune
 
@@ -23,7 +25,14 @@ func newRow(parent *Document, s string) *Row {
 		render = append(render, ch)
 	}
 
-	return &Row{parent, chars, render, []int{}}
+	return &Row{
+		at,
+		parent,
+		chars,
+		render,
+		[]int{},
+		false,
+	}
 }
 
 func (r *Row) Size() int {
@@ -154,7 +163,7 @@ func (r *Row) updateSyntax() {
 
 	prevSep := true
 	inString := '0'
-	inComment := false
+	inComment := r.index > 0 && r.parent.rows[r.index-1].startsComment
 	for i < r.RenderSize() {
 		ch := r.render[i]
 		prevHl := highlight.Normal
@@ -283,6 +292,12 @@ func (r *Row) updateSyntax() {
 		prevSep = char.IsSeparator(ch)
 		i++
 	}
+
+	changed := r.startsComment != inComment
+	r.startsComment = inComment
+	if changed && (r.index+1) < r.parent.RowCount() {
+		r.parent.rows[r.index+1].updateSyntax()
+	}
 }
 
 func (r *Row) toString() string {
diff --git a/editor/document/row_test.go b/editor/document/row_test.go
index b9e448f..d46e4a9 100644
--- a/editor/document/row_test.go
+++ b/editor/document/row_test.go
@@ -6,7 +6,7 @@ var doc = NewDocument()
 
 func TestNewRow(t *testing.T) {
 	str := "abcdefg"
-	row := newRow(doc, str)
+	row := newRow(1, doc, str)
 
 	got := string(row.chars)
 	want := str
@@ -18,7 +18,7 @@ func TestNewRow(t *testing.T) {
 
 func TestRowSize(t *testing.T) {
 	str := "abcdefg"
-	row := newRow(doc, str)
+	row := newRow(1, doc, str)
 
 	got := row.Size()
 	want := 7
@@ -30,7 +30,7 @@ func TestRowSize(t *testing.T) {
 
 func TestRenderSize(t *testing.T) {
 	str := "\tabcdefg"
-	row := newRow(doc, str)
+	row := newRow(1, doc, str)
 	row.update()
 
 	got := row.RenderSize()
@@ -57,7 +57,7 @@ var insertRuneTests = []insertRune{
 
 func TestInsertRune(t *testing.T) {
 	for _, test := range insertRuneTests {
-		row := newRow(doc, test.initial)
+		row := newRow(1, doc, test.initial)
 		row.insertRune(test.ch, test.at)
 
 		if row.Size() != 5 {
diff --git a/justfile b/justfile
index 2d80492..d88dea6 100644
--- a/justfile
+++ b/justfile
@@ -4,7 +4,7 @@ default:
 
 # Run all the tests
 test:
-	go test ./... -v
+	go test ./...
 
 _cover:
 	go test ./... -coverprofile=coverage.out