From c18181c064d708c9df8433dfa4c58df349dfc76d Mon Sep 17 00:00:00 2001
From: "Timothy J. Warren" <tim@timshomepage.net>
Date: Wed, 7 Apr 2021 12:32:22 -0400
Subject: [PATCH] Refactor highlighting to use highlight array

---
 internal/editor/document/row.go        | 17 ++++++++++++++++-
 internal/editor/draw.go                | 25 +++++++++++++++++--------
 internal/editor/highlight/constants.go |  9 +++++++++
 internal/editor/highlight/fn.go        | 12 ++++++++++++
 internal/gilo/constants.go             |  1 +
 5 files changed, 55 insertions(+), 9 deletions(-)
 create mode 100644 internal/editor/highlight/constants.go
 create mode 100644 internal/editor/highlight/fn.go

diff --git a/internal/editor/document/row.go b/internal/editor/document/row.go
index 3ffe87a..1fe40a7 100644
--- a/internal/editor/document/row.go
+++ b/internal/editor/document/row.go
@@ -2,12 +2,15 @@ package document
 
 import (
 	"strings"
+	"timshome.page/gilo/internal/editor/highlight"
 	"timshome.page/gilo/internal/gilo"
+	"unicode"
 )
 
 type Row struct {
 	chars  []rune
 	render []rune
+	Hl     []int
 }
 
 func newRow(s string) *Row {
@@ -19,7 +22,7 @@ func newRow(s string) *Row {
 		render = append(render, ch)
 	}
 
-	return &Row{chars, render}
+	return &Row{chars, render, []int{}}
 }
 
 func (r *Row) Size() int {
@@ -98,6 +101,18 @@ func (r *Row) update() {
 	for _, ch := range str {
 		r.render = append(r.render, ch)
 	}
+
+	r.updateSyntax()
+}
+
+func (r *Row) updateSyntax() {
+	for _, ch := range r.render {
+		if unicode.IsDigit(ch) {
+			r.Hl = append(r.Hl, highlight.Number)
+		} else {
+			r.Hl = append(r.Hl, highlight.Normal)
+		}
+	}
 }
 
 func (r *Row) toString() string {
diff --git a/internal/editor/draw.go b/internal/editor/draw.go
index 5531f5e..ca2be71 100644
--- a/internal/editor/draw.go
+++ b/internal/editor/draw.go
@@ -5,9 +5,9 @@ import (
 	"fmt"
 	"strings"
 	"time"
+	"timshome.page/gilo/internal/editor/highlight"
 	"timshome.page/gilo/internal/gilo"
 	"timshome.page/gilo/internal/terminal"
-	"unicode"
 )
 
 // ----------------------------------------------------------------------------
@@ -74,20 +74,29 @@ func (e *editor) drawRows(ab *gilo.Buffer) {
 				continue
 			}
 
-			// rowLen := e.document.GetRow(fileRow).RenderSize() - e.offset.X
+			currentColor := terminal.DefaultFGColor
+			row := e.document.GetRow(fileRow)
+
+			for i, ch := range row.Render(e.offset) {
+				if row.Hl[i] == highlight.Normal {
+					if currentColor != terminal.DefaultFGColor {
+						ab.Append(terminal.DefaultFGColor)
+						currentColor = terminal.DefaultFGColor
+					}
 
-			for _, ch := range e.document.GetRow(fileRow).Render(e.offset) {
-				if unicode.IsDigit(ch) {
-					ab.Append(terminal.FGRed)
 					ab.AppendRune(ch)
-					ab.Append(terminal.DefaultFGColor)
 				} else {
+					color := highlight.SyntaxToColor(row.Hl[i])
+					if color != currentColor {
+						currentColor = color
+						ab.Append(color)
+					}
+
 					ab.AppendRune(ch)
 				}
 			}
 
-			// outputRow := gilo.Truncate(e.document.GetRow(fileRow).Render(e.offset), rowLen)
-			// ab.Append(outputRow)
+			ab.Append(terminal.DefaultFGColor)
 		}
 
 		ab.AppendLn(terminal.ClearLine)
diff --git a/internal/editor/highlight/constants.go b/internal/editor/highlight/constants.go
new file mode 100644
index 0000000..a78d120
--- /dev/null
+++ b/internal/editor/highlight/constants.go
@@ -0,0 +1,9 @@
+package highlight
+
+// ----------------------------------------------------------------------------
+// !Syntax Highlighting Constants
+// ----------------------------------------------------------------------------
+const (
+	Normal = iota
+	Number
+)
\ No newline at end of file
diff --git a/internal/editor/highlight/fn.go b/internal/editor/highlight/fn.go
new file mode 100644
index 0000000..33e88c2
--- /dev/null
+++ b/internal/editor/highlight/fn.go
@@ -0,0 +1,12 @@
+package highlight
+
+import "timshome.page/gilo/internal/terminal"
+
+func SyntaxToColor(hl int) string {
+	switch hl {
+	case Number:
+		return terminal.FGRed
+	default:
+		return terminal.DefaultFGColor
+	}
+}
diff --git a/internal/gilo/constants.go b/internal/gilo/constants.go
index b2e9bcf..04b4c50 100644
--- a/internal/gilo/constants.go
+++ b/internal/gilo/constants.go
@@ -9,3 +9,4 @@ const (
 	TabSize   = 4
 	QuitTimes = 3
 )
+