add more ways to interact with a buffer's lines

1 files changed, 16 insertions, 0 deletions

diff --git a/go/ui/buffer.go b/go/ui/buffer.go
index 3abbc2cc..8294c905 100644
--- a/go/ui/buffer.go
+++ b/go/ui/buffer.go
@@ -2,6 +2,7 @@ package ui
 
 import (
 	"image/color"
+	"iter"
 
 	"github.com/hajimehoshi/ebiten/v2"
 	"github.com/hajimehoshi/ebiten/v2/text/v2"
@@ -72,6 +73,21 @@ func (b *Buffer) Remove(idx int) {
 	b.ForceRedraw()
 }
 
+func (b *Buffer) PrefixLine(idx int, prefix string) {
+	b.lines[idx] = prefix + b.lines[idx]
+	b.ForceRedraw()
+}
+
+func (b *Buffer) LinesSeq() iter.Seq[string] {
+	return func(yield func(string) bool) {
+		for _, l := range b.lines {
+			if !yield(l) {
+				return
+			}
+		}
+	}
+}
+
 func (*Buffer) IsScrollable() bool { return true }
 
 func (b *Buffer) Scroll(x, y int) {