Netmime_tut. Parsers for MIME headers are now in
Netmime_header. Parser and printers for MIME channels are now in
[ `File of string | `Memory ]
`File namemeans in the file
name. The body is stored in decoded form (i.e. without transfer encoding).
exception Immutable of
mime_body_ro), and after that the full class type including write access is defined (
The idea is that you can write functions that take an ro value as input to indicate that they do not modify the value. For example:
let number_of_fields (h:#mime_header_ro) = List.length (h#fields)
This function accepts both
mime_header_ro values as
input, but the typing ensures that the function cannot mutate anything.
There is another way to ensure that a header or body is not modified.
The read-only flag can be set when creating the object, and this flag
causes that all trials to modify the value will raise the exception
Immutable. Of course, such trials of mutation are only detected at
The advantage of the read-only flag is that it even works if
mutation depends on a condition, but it can be ensured that this
condition is never true. Furthermore, typing is much simpler (getting
subtyping correct can be annoying).
class type mime_header_ro =
class type mime_header =
class type mime_body_ro =
class type mime_body =
(mime_header, mime_body)as simple MIME message with one header and one body. Of course, this simple representation does not support multi-part messages (attachments). For that reason, the
complex_mime_messagewas invented: The body can be further structured as a sequence of parts that are complex messages themselves.
For example, a mail message with an attachment is usually represented as
(mail_header, `Parts [ (main_header, `Body main_body); (att_header, `Body att_body) ] )
mail_header is the real header of the mail message.
main_header is the header of the main message, usually
only containing the content type of
main_body, the body
of the main message. The attachment has also its own
att_header, again usually only containing the content type,
and the data of the attachment can be found in
Nowadays, mails have often even a more complicated structure
`Parts containing nested
is recursive, any kind of nesting can be easily represented.
mime_header * complex_mime_body
[ `Body of mime_body | `Parts of complex_mime_message list ]
mime_header_ro * complex_mime_body_ro
[ `Body of mime_body_ro
| `Parts of complex_mime_message_ro list ]
`Parts , i.e.
`Partstogether with an empty list, is considered as illegal. Such a value cannot be transformed into printable text.
mime_header * [ `Body of mime_body ]
mime_header_ro * [ `Body of mime_body_ro ]
class basic_mime_header :
(string * string) list ->
val basic_mime_header :
(string * string) list -> mime_header
class wrap_mime_header :
class wrap_mime_header_ro :
val wrap_mime_header_ro :
#mime_header_ro -> mime_header
class memory_mime_body :
mime_bodywhere the value is stored in-memory.
val memory_mime_body :
string -> mime_body
class file_mime_body :
?fin:bool -> string ->
mime_bodywhere the value is stored in an external file.
val file_mime_body :
?fin:bool -> string -> mime_body
class wrap_mime_body :
class wrap_mime_body_ro :
val wrap_mime_body_ro :
#mime_body_ro -> mime_body
val wrap_complex_mime_message_ro :
complex_mime_message_ro -> complex_mime_message