Library for parsring/generating Maildir filenames.

maildir.go

@@ -0,0 +1,80 @@
+// Package email helps manage emails stored in Maildir format.  A good
+// write-up on the format is available at http://cr.yp.to/proto/maildir.html
+package email
+
+import (
+	"bytes"
+	"fmt"
+	"strings"
+)
+
+// Info represents the info bits encoded as the suffix of a Maildir file.  info
+// starting with "2,": Each character after the comma is an independent flag.
+//   Flag "P" (passed): the user has resent/forwarded/bounced this message to someone else.
+//   Flag "R" (replied): the user has replied to this message.
+//   Flag "S" (seen): the user has viewed this message, though perhaps he didn't read all the way through it.
+//   Flag "T" (trashed): the user has moved this message to the trash; the trash will be emptied by a later user action.
+//   Flag "D" (draft): the user considers this message a draft; toggled at user discretion.
+//   Flag "F" (flagged): user-defined flag; toggled at user discretion.
+// New flags may be defined later. Flags must be stored in ASCII order: e.g., "2,FRS".
+type Info struct {
+	Base    string // The portion of the filename before the ':'.
+	Passed  bool
+	Replied bool
+	Seen    bool
+	Trashed bool
+	Draft   bool
+	Flagged bool
+}
+
+// NewInfo returns an Info containing the version 2 Maildir flags parsed from
+// fn's suffix.
+func NewInfo(fn string) (info Info) {
+	info.Base = fn
+	i := strings.LastIndex(fn, ":")
+	if i != -1 {
+		info.Base = fn[:i]
+		infoStr := fn[i:]
+		i = strings.Index(infoStr, ",")
+		if i == -1 {
+			return
+		}
+
+		flags := infoStr[i:]
+		info.Passed = strings.Contains(flags, "P")
+		info.Replied = strings.Contains(flags, "R")
+		info.Seen = strings.Contains(flags, "S")
+		info.Trashed = strings.Contains(flags, "T")
+		info.Draft = strings.Contains(flags, "D")
+		info.Flagged = strings.Contains(flags, "F")
+	}
+	return
+}
+
+func (i Info) String() string {
+	if i.Passed || i.Replied || i.Seen || i.Trashed || i.Draft || i.Flagged {
+		b := new(bytes.Buffer)
+		fmt.Fprintf(b, "%s:2,", i.Base)
+		if i.Passed {
+			fmt.Fprint(b, "P")
+		}
+		if i.Replied {
+			fmt.Fprint(b, "R")
+		}
+		if i.Seen {
+			fmt.Fprint(b, "S")
+		}
+		if i.Trashed {
+			fmt.Fprint(b, "T")
+		}
+		if i.Draft {
+			fmt.Fprint(b, "D")
+		}
+		if i.Flagged {
+			fmt.Fprint(b, "F")
+		}
+		return b.String()
+	}
+
+	return i.Base
+}

maildir_test.go

@@ -0,0 +1,91 @@
+package email
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestInfo(t *testing.T) {
+	datum := []struct {
+		input string
+		want  Info
+		clean string // Expected result from .String(), empty defaults to input.
+	}{
+		{
+			input: "mail:2,PRSTDF",
+			want: Info{
+				Base:    "mail",
+				Passed:  true,
+				Replied: true,
+				Seen:    true,
+				Trashed: true,
+				Draft:   true,
+				Flagged: true,
+			},
+		},
+		{
+			input: "mail:2,PRTDF",
+			want: Info{
+				Base:    "mail",
+				Passed:  true,
+				Replied: true,
+				Seen:    false,
+				Trashed: true,
+				Draft:   true,
+				Flagged: true,
+			},
+		},
+		{
+			input: "mail:2,PRSTD",
+			want: Info{
+				Base:    "mail",
+				Passed:  true,
+				Replied: true,
+				Seen:    true,
+				Trashed: true,
+				Draft:   true,
+				Flagged: false,
+			},
+		},
+		{
+			input: "mail:2,RSTDF",
+			want: Info{
+				Base:    "mail",
+				Passed:  false,
+				Replied: true,
+				Seen:    true,
+				Trashed: true,
+				Draft:   true,
+				Flagged: true,
+			},
+		},
+		{
+			input: "mail",
+			want: Info{
+				Base: "mail",
+			},
+		},
+		{
+			input: "mail:2,",
+			want: Info{
+				Base: "mail",
+			},
+			clean: "mail",
+		},
+	}
+
+	for i, d := range datum {
+		got := NewInfo(d.input)
+		if !reflect.DeepEqual(d.want, got) {
+			t.Errorf("%d. Got %#v want %#v", i, got, d.want)
+		}
+
+		expected := d.input
+		if d.clean != "" {
+			expected = d.clean
+		}
+		if gotStr := got.String(); gotStr != expected {
+			t.Errorf("%d. Got %q want %q", i, gotStr, expected)
+		}
+	}
+}