Added MatchString

test/readerat.go

@@ -6,7 +6,9 @@ package test
 import (
 	"io"
 
+	"git.codemonkeysoftware.net/b/gigaparsec"
 	"git.codemonkeysoftware.net/b/gigaparsec/cursor"
+	"github.com/shoenig/test"
 )
 
 type errReaderAt struct {
@@ -44,3 +46,7 @@ func (c errCursor[T]) Pos() uint64 {
 func ErrCursor[T any](err error) cursor.Cursor[T] {
 	return errCursor[T]{err: err}
 }
+
+func StateIsAt[Input any](t test.T, s gigaparsec.State[Input], pos uint64) {
+	test.EqOp(t, pos, s.Pos(), test.Sprintf("expected parser state to be at position %d, got %d", pos, s.Pos()))
+}