Create a compat/json compatibility library

2 files changed, 54 insertions, 0 deletions

diff --git a/internal/borrowed_tags.go b/internal/borrowed_tags.go
new file mode 100644
index 0000000..e2bb54a
--- /dev/null
+++ b/internal/borrowed_tags.go
@@ -0,0 +1,38 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package internal // MODIFIED
+
+import (
+	"strings"
+)
+
+// tagOptions is the string following a comma in a struct field's "json"
+// tag, or the empty string. It does not include the leading comma.
+type tagOptions string
+
+// parseTag splits a struct field's json tag into its name and
+// comma-separated options.
+func parseTag(tag string) (string, tagOptions) {
+	tag, opt, _ := strings.Cut(tag, ",")
+	return tag, tagOptions(opt)
+}
+
+// Contains reports whether a comma-separated list of options
+// contains a particular substr flag. substr must be surrounded by a
+// string boundary or commas.
+func (o tagOptions) Contains(optionName string) bool {
+	if len(o) == 0 {
+		return false
+	}
+	s := string(o)
+	for s != "" {
+		var name string
+		name, s, _ = strings.Cut(s, ",")
+		if name == optionName {
+			return true
+		}
+	}
+	return false
+}
diff --git a/internal/export.go b/internal/export.go
new file mode 100644
index 0000000..d8cf622
--- /dev/null
+++ b/internal/export.go
@@ -0,0 +1,16 @@
+// Copyright (C) 2022  Luke Shumaker <lukeshu@lukeshu.com>
+//
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+package internal
+
+import (
+	"io"
+)
+
+var ParseTag = parseTag
+
+var (
+	EncodeStringFromBytes  func(io.Writer, []byte)
+	EncodeStringFromString func(io.Writer, string)
+)