1 files changed, 95 insertions, 0 deletions
diff --git a/src/pkg/mail/message.go b/src/pkg/mail/message.go
new file mode 100644
index 000000000..9723863fe
--- /dev/null
+++ b/src/pkg/mail/message.go
@@ -0,0 +1,95 @@
+// 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 mail implements parsing of mail messages according to RFC 5322.
+package mail
+
+import (
+	"bufio"
+	"io"
+	"net/textproto"
+	"os"
+	"time"
+)
+
+// A Message represents a parsed mail message.
+type Message struct {
+	Header Header
+	Body   io.Reader
+}
+
+// ReadMessage reads a message from r.
+// The headers are parsed, and the body of the message will be reading from r.
+func ReadMessage(r io.Reader) (msg *Message, err os.Error) {
+	tp := textproto.NewReader(bufio.NewReader(r))
+
+	hdr, err := tp.ReadMIMEHeader()
+	if err != nil {
+		return nil, err
+	}
+
+	return &Message{
+		Header: Header(hdr),
+		Body:   tp.R,
+	}, nil
+}
+
+// Layouts suitable for passing to time.Parse.
+// These are tried in order.
+var dateLayouts []string
+
+func init() {
+	// Generate layouts based on RFC 5322, section 3.3.
+
+	dows := [...]string{"", "Mon, "}     // day-of-week
+	days := [...]string{"2", "02"}       // day = 1*2DIGIT
+	years := [...]string{"2006", "06"}   // year = 4*DIGIT / 2*DIGIT
+	seconds := [...]string{":05", ""}    // second
+	zones := [...]string{"-0700", "MST"} // zone = (("+" / "-") 4DIGIT) / "GMT" / ...
+
+	for _, dow := range dows {
+		for _, day := range days {
+			for _, year := range years {
+				for _, second := range seconds {
+					for _, zone := range zones {
+						s := dow + day + " Jan " + year + " 15:04" + second + " " + zone
+						dateLayouts = append(dateLayouts, s)
+					}
+				}
+			}
+		}
+	}
+}
+
+func parseDate(date string) (*time.Time, os.Error) {
+	for _, layout := range dateLayouts {
+		t, err := time.Parse(layout, date)
+		if err == nil {
+			return t, nil
+		}
+	}
+	return nil, os.ErrorString("mail: header could not be parsed")
+}
+
+// TODO(dsymonds): Parsers for more specific headers such as To, From, etc.
+
+// A Header represents the key-value pairs in a mail message header.
+type Header map[string][]string
+
+// Get gets the first value associated with the given key.
+// If there are no values associated with the key, Get returns "".
+func (h Header) Get(key string) string {
+	return textproto.MIMEHeader(h).Get(key)
+}
+
+var ErrHeaderNotPresent = os.ErrorString("mail: header not in message")
+
+// Date parses the Date header field.
+func (h Header) Date() (*time.Time, os.Error) {
+	hdr := h.Get("Date")
+	if hdr == "" {
+		return nil, ErrHeaderNotPresent
+	}
+	return parseDate(hdr)
+}