feat: custom address/date parser based on rfc5322 abnf

pkg/message/rfc5322/atom.go

@@ -0,0 +1,49 @@
+// Copyright (c) 2020 Proton Technologies AG
+//
+// This file is part of ProtonMail Bridge.
+//
+// ProtonMail Bridge is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// ProtonMail Bridge is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with ProtonMail Bridge.  If not, see <https://www.gnu.org/licenses/>.
+
+package rfc5322
+
+import (
+	"github.com/ProtonMail/proton-bridge/pkg/message/rfc5322/parser"
+	"github.com/sirupsen/logrus"
+)
+
+type atom struct {
+	value string
+}
+
+func (w *walker) EnterAtom(ctx *parser.AtomContext) {
+	logrus.WithField("text", ctx.GetText()).Trace("Entering atom")
+
+	w.enter(&atom{
+		value: ctx.GetText(),
+	})
+}
+
+func (w *walker) ExitAtom(ctx *parser.AtomContext) {
+	logrus.WithField("text", ctx.GetText()).Trace("Exiting atom")
+
+	type withAtom interface {
+		withAtom(*atom)
+	}
+
+	res := w.exit().(*atom)
+
+	if parent, ok := w.parent().(withAtom); ok {
+		parent.withAtom(res)
+	}
+}