textcore: add metadata to Lines -- key for storing vcs repo in Code

text/lines/lines.go

@@ -17,6 +17,7 @@ import (
 
 	"cogentcore.org/core/base/errors"
 	"cogentcore.org/core/base/fileinfo"
+	"cogentcore.org/core/base/metadata"
 	"cogentcore.org/core/base/slicesx"
 	"cogentcore.org/core/text/highlighting"
 	"cogentcore.org/core/text/parse"
@@ -83,6 +84,12 @@ type Lines struct {
 	// save current version as a different file. It must block until the user responds.
 	FileModPromptFunc func()
 
+	// Meta can be used to maintain misc metadata associated with the Lines text,
+	// which allows the Lines object to be the primary data type for applications
+	// dealing with text data, if there are just a few additional data elements needed.
+	// Use standard Go camel-case key names, standards in [metadata].
+	Meta metadata.Data
+
 	// fontStyle is the default font styling to use for markup.
 	// Is set to use the monospace font.
 	fontStyle *rich.Style
@@ -174,6 +181,8 @@ type Lines struct {
 	sync.Mutex
 }
 
+func (ls *Lines) Metadata() *metadata.Data { return &ls.Meta }
+
 // numLines returns number of lines
 func (ls *Lines) numLines() int {
 	return len(ls.lines)