"""
pygments.lexers.mime
~~~~~~~~~~~~~~~~~~~~
Lexer
for Multipurpose Internet Mail Extensions (MIME) data.
:copyright: Copyright
2006-
2024 by the Pygments team, see AUTHORS.
:license: BSD, see LICENSE
for details.
"""
import re
from pygments.lexer
import RegexLexer, include
from pygments.lexers
import get_lexer_for_mimetype
from pygments.token
import Text, Name, String, Operator, Comment, Other
from pygments.util
import get_int_opt, ClassNotFound
__all__ = [
"MIMELexer"]
class MIMELexer(RegexLexer):
"""
Lexer
for Multipurpose Internet Mail Extensions (MIME) data. This lexer
is
designed to process nested multipart data.
It assumes that the given data contains both header
and body (
and is
split at an empty line).
If no valid header
is found, then the entire data
will be treated
as body.
Additional options accepted:
`MIME-max-level`
Max recursion level
for nested MIME structure. Any negative number
would treated
as unlimited. (default: -
1)
`Content-Type`
Treat the data
as a specific content type. Useful when header
is
missing,
or this lexer would
try to parse
from header. (default:
`text/plain`)
`Multipart-Boundary`
Set the default multipart boundary delimiter. This option
is only used
when `Content-Type`
is `multipart`
and header
is missing. This lexer
would
try to parse
from header by default. (default:
None)
`Content-Transfer-Encoding`
Treat the data
as a specific encoding.
Or this lexer would
try to parse
from header by default. (default:
None)
"""
name =
"MIME"
aliases = [
"mime"]
mimetypes = [
"multipart/mixed",
"multipart/related",
"multipart/alternative"]
url =
'https://en.wikipedia.org/wiki/MIME'
version_added =
'2.5'
def __init__(self, **options):
super().__init__(**options)
self.boundary = options.get(
"Multipart-Boundary")
self.content_transfer_encoding = options.get(
"Content_Transfer_Encoding")
self.content_type = options.get(
"Content_Type",
"text/plain")
self.max_nested_level = get_int_opt(options,
"MIME-max-level", -
1)
def get_header_tokens(self, match):
field = match.group(
1)
if field.lower()
in self.attention_headers:
yield match.start(
1), Name.Tag, field +
":"
yield match.start(
2), Text.Whitespace, match.group(
2)
pos = match.end(
2)
body = match.group(
3)
for i, t, v
in self.get_tokens_unprocessed(body, (
"root", field.lower())):
yield pos + i, t, v
else:
yield match.start(), Comment, match.group()
def get_body_tokens(self, match):
pos_body_start = match.start()
entire_body = match.group()
# skip first newline
if entire_body[
0] ==
'\n':
yield pos_body_start, Text.Whitespace,
'\n'
pos_body_start = pos_body_start +
1
entire_body = entire_body[
1:]
# if it is not a multipart
if not self.content_type.startswith(
"multipart")
or not self.boundary:
for i, t, v
in self.get_bodypart_tokens(entire_body):
yield pos_body_start + i, t, v
return
# find boundary
bdry_pattern = rf
"^--{re.escape(self.boundary)}(--)?\n"
bdry_matcher = re.compile(bdry_pattern, re.MULTILINE)
# some data has prefix text before first boundary
m = bdry_matcher.search(entire_body)
if m:
pos_part_start = pos_body_start + m.end()
pos_iter_start = lpos_end = m.end()
yield pos_body_start, Text, entire_body[:m.start()]
yield pos_body_start + lpos_end, String.Delimiter, m.group()
else:
pos_part_start = pos_body_start
pos_iter_start =
0
# process tokens of each body part
for m
in bdry_matcher.finditer(entire_body, pos_iter_start):
# bodypart
lpos_start = pos_part_start - pos_body_start
lpos_end = m.start()
part = entire_body[lpos_start:lpos_end]
for i, t, v
in self.get_bodypart_tokens(part):
yield pos_part_start + i, t, v
# boundary
yield pos_body_start + lpos_end, String.Delimiter, m.group()
pos_part_start = pos_body_start + m.end()
# some data has suffix text after last boundary
lpos_start = pos_part_start - pos_body_start
if lpos_start != len(entire_body):
yield pos_part_start, Text, entire_body[lpos_start:]
def get_bodypart_tokens(self, text):
# return if:
# * no content
# * no content type specific
# * content encoding is not readable
# * max recurrsion exceed
if not text.strip()
or not self.content_type:
return [(
0, Other, text)]
cte = self.content_transfer_encoding
if cte
and cte
not in {
"8bit",
"7bit",
"quoted-printable"}:
return [(
0, Other, text)]
if self.max_nested_level ==
0:
return [(
0, Other, text)]
# get lexer
try:
lexer = get_lexer_for_mimetype(self.content_type)
except ClassNotFound:
return [(
0, Other, text)]
if isinstance(lexer, type(self)):
lexer.max_nested_level = self.max_nested_level -
1
return lexer.get_tokens_unprocessed(text)
def store_content_type(self, match):
self.content_type = match.group(
1)
prefix_len = match.start(
1) - match.start(
0)
yield match.start(
0), Text.Whitespace, match.group(
0)[:prefix_len]
yield match.start(
1), Name.Label, match.group(
2)
yield match.end(
2), String.Delimiter,
'/'
yield match.start(
3), Name.Label, match.group(
3)
def get_content_type_subtokens(self, match):
yield match.start(
1), Text, match.group(
1)
yield match.start(
2), Text.Whitespace, match.group(
2)
yield match.start(
3), Name.Attribute, match.group(
3)
yield match.start(
4), Operator, match.group(
4)
yield match.start(
5), String, match.group(
5)
if match.group(
3).lower() ==
"boundary":
boundary = match.group(
5).strip()
if boundary[
0] ==
'"' and boundary[-
1] ==
'"':
boundary = boundary[
1:-
1]
self.boundary = boundary
def store_content_transfer_encoding(self, match):
self.content_transfer_encoding = match.group(
0).lower()
yield match.start(
0), Name.Constant, match.group(
0)
attention_headers = {
"content-type",
"content-transfer-encoding"}
tokens = {
"root": [
(r
"^([\w-]+):( *)([\s\S]*?\n)(?![ \t])", get_header_tokens),
(r
"^$[\s\S]+", get_body_tokens),
],
"header": [
# folding
(r
"\n[ \t]", Text.Whitespace),
(r
"\n(?![ \t])", Text.Whitespace,
"#pop"),
],
"content-type": [
include(
"header"),
(
r
"^\s*((multipart|application|audio|font|image|model|text|video"
r
"|message)/([\w-]+))",
store_content_type,
),
(r
'(;)((?:[ \t]|\n[ \t])*)([\w:-]+)(=)([\s\S]*?)(?=;|\n(?![ \t]))',
get_content_type_subtokens),
(r
';[ \t]*\n(?![ \t])', Text,
'#pop'),
],
"content-transfer-encoding": [
include(
"header"),
(r
"([\w-]+)", store_content_transfer_encoding),
],
}
