Move printedFull closer to its use, document

file.go

@@ -68,6 +68,15 @@ func (nptf *notPlainTextFlag) Type() string {
 	return "short|full|skip" // ???
 }
 
+var (
+	// printedFull is set by file() if it prints a full file's matches
+	// (i.e. a header line, then the match lines). It is cleared if we
+	// just printed a "Binary file <foo> matches" line. It lets us have a
+	// nice one-line separator between full files, but show the binary
+	// matches compactly.
+	printedFull bool
+)
+
 func file(path string, data []byte) {
 	var short string
 	isBinary, isMinified := notPlainText(data)

main.go

@@ -63,7 +63,6 @@ var (
 	ignoreCase   bool
 	noColour     bool
 	display      *Display
-	printedFull  bool
 )
 
 func init() {