"""MyST Markdown parser for docutils."""
from dataclasses import Field
from typing import Any, Callable, Dict, Iterable, List, Optional, Sequence, Tuple, Union
from docutils import frontend, nodes
from docutils.core import default_description, publish_cmdline
from docutils.parsers.rst import Parser as RstParser
from typing_extensions import Literal, get_args, get_origin
from myst_parser.config.main import (
MdParserConfig,
TopmatterReadError,
merge_file_level,
read_topmatter,
)
from myst_parser.mdit_to_docutils.base import DocutilsRenderer, create_warning
from myst_parser.parsers.mdit import create_md_parser
def _validate_int(
setting, value, option_parser, config_parser=None, config_section=None
) -> int:
"""Validate an integer setting."""
return int(value)
def _create_validate_tuple(length: int) -> Callable[..., Tuple[str, ...]]:
"""Create a validator for a tuple of length `length`."""
def _validate(
setting, value, option_parser, config_parser=None, config_section=None
):
string_list = frontend.validate_comma_separated_list(
setting, value, option_parser, config_parser, config_section
)
if len(string_list) != length:
raise ValueError(
f"Expecting {length} items in {setting}, got {len(string_list)}."
)
return tuple(string_list)
return _validate
class Unset:
"""A sentinel class for unset settings."""
def __repr__(self):
return "UNSET"
DOCUTILS_UNSET = Unset()
"""Sentinel for arguments not set through docutils.conf."""
DOCUTILS_EXCLUDED_ARGS = (
# docutils.conf can't represent callables
"heading_slug_func",
# docutils.conf can't represent dicts
"html_meta",
"substitutions",
# we can't add substitutions so not needed
"sub_delimiters",
# sphinx only options
"heading_anchors",
"ref_domains",
"update_mathjax",
"mathjax_classes",
)
"""Names of settings that cannot be set in docutils.conf."""
def _attr_to_optparse_option(at: Field, default: Any) -> Tuple[dict, str]:
"""Convert a field into a Docutils optparse options dict."""
if at.type is int:
return {"metavar": "<int>", "validator": _validate_int}, f"(default: {default})"
if at.type is bool:
return {
"metavar": "<boolean>",
"validator": frontend.validate_boolean,
}, f"(default: {default})"
if at.type is str:
return {
"metavar": "<str>",
}, f"(default: '{default}')"
if get_origin(at.type) is Literal and all(
isinstance(a, str) for a in get_args(at.type)
):
args = get_args(at.type)
return {
"metavar": f"<{'|'.join(repr(a) for a in args)}>",
"type": "choice",
"choices": args,
}, f"(default: {default!r})"
if at.type in (Iterable[str], Sequence[str]):
return {
"metavar": "<comma-delimited>",
"validator": frontend.validate_comma_separated_list,
}, f"(default: '{','.join(default)}')"
if at.type == Tuple[str, str]:
return {
"metavar": "<str,str>",
"validator": _create_validate_tuple(2),
}, f"(default: '{','.join(default)}')"
if at.type == Union[int, type(None)]:
return {
"metavar": "<null|int>",
"validator": _validate_int,
}, f"(default: {default})"
if at.type == Union[Iterable[str], type(None)]:
default_str = ",".join(default) if default else ""
return {
"metavar": "<null|comma-delimited>",
"validator": frontend.validate_comma_separated_list,
}, f"(default: {default_str!r})"
raise AssertionError(
f"Configuration option {at.name} not set up for use in docutils.conf."
)
def attr_to_optparse_option(
attribute: Field, default: Any, prefix: str = "myst_"
) -> Tuple[str, List[str], Dict[str, Any]]:
"""Convert an ``MdParserConfig`` attribute into a Docutils setting tuple.
:returns: A tuple of ``(help string, option flags, optparse kwargs)``.
"""
name = f"{prefix}{attribute.name}"
flag = "--" + name.replace("_", "-")
options = {"dest": name, "default": DOCUTILS_UNSET}
at_options, type_str = _attr_to_optparse_option(attribute, default)
options.update(at_options)
help_str = attribute.metadata.get("help", "") if attribute.metadata else ""
return (f"{help_str} {type_str}", [flag], options)
def create_myst_settings_spec(
excluded: Sequence[str], config_cls=MdParserConfig, prefix: str = "myst_"
):
"""Return a list of Docutils setting for the docutils MyST section."""
defaults = config_cls()
return tuple(
attr_to_optparse_option(at, getattr(defaults, at.name), prefix)
for at in config_cls.get_fields()
if at.name not in excluded
)
def create_myst_config(
settings: frontend.Values,
excluded: Sequence[str],
config_cls=MdParserConfig,
prefix: str = "myst_",
):
"""Create a configuration instance from the given settings."""
values = {}
for attribute in config_cls.get_fields():
if attribute.name in excluded:
continue
setting = f"{prefix}{attribute.name}"
val = getattr(settings, setting, DOCUTILS_UNSET)
if val is not DOCUTILS_UNSET:
values[attribute.name] = val
return config_cls(**values)
[docs]class Parser(RstParser):
"""Docutils parser for Markedly Structured Text (MyST)."""
supported: Tuple[str, ...] = ("md", "markdown", "myst")
"""Aliases this parser supports."""
settings_spec = (
"MyST options",
None,
create_myst_settings_spec(DOCUTILS_EXCLUDED_ARGS),
*RstParser.settings_spec,
)
"""Runtime settings specification."""
config_section = "myst parser"
config_section_dependencies = ("parsers",)
translate_section_name = None
[docs] def parse(self, inputstring: str, document: nodes.document) -> None:
"""Parse source text.
:param inputstring: The source string to parse
:param document: The root docutils node to add AST elements to
"""
self.setup_parse(inputstring, document)
# check for exorbitantly long lines
if hasattr(document.settings, "line_length_limit"):
for i, line in enumerate(inputstring.split("\n")):
if len(line) > document.settings.line_length_limit:
error = document.reporter.error(
f"Line {i+1} exceeds the line-length-limit:"
f" {document.settings.line_length_limit}."
)
document.append(error)
return
# create parsing configuration from the global config
try:
config = create_myst_config(document.settings, DOCUTILS_EXCLUDED_ARGS)
except Exception as exc:
error = document.reporter.error(f"Global myst configuration invalid: {exc}")
document.append(error)
config = MdParserConfig()
# update the global config with the file-level config
try:
topmatter = read_topmatter(inputstring)
except TopmatterReadError:
pass # this will be reported during the render
else:
if topmatter:
warning = lambda wtype, msg: create_warning( # noqa: E731
document, msg, line=1, append_to=document, subtype=wtype
)
config = merge_file_level(config, topmatter, warning)
# parse content
parser = create_md_parser(config, DocutilsRenderer)
parser.options["document"] = document
parser.render(inputstring)
# post-processing
# replace raw nodes if raw is not allowed
if not getattr(document.settings, "raw_enabled", True):
for node in document.traverse(nodes.raw):
warning = document.reporter.warning("Raw content disabled.")
node.parent.replace(node, warning)
self.finish_parse()
def _run_cli(writer_name: str, writer_description: str, argv: Optional[List[str]]):
"""Run the command line interface for a particular writer."""
publish_cmdline(
parser=Parser(),
writer_name=writer_name,
description=(
f"Generates {writer_description} from standalone MyST sources.\n{default_description}"
),
argv=argv,
)
def cli_html(argv: Optional[List[str]] = None) -> None:
"""Cmdline entrypoint for converting MyST to HTML."""
_run_cli("html", "(X)HTML documents", argv)
def cli_html5(argv: Optional[List[str]] = None):
"""Cmdline entrypoint for converting MyST to HTML5."""
_run_cli("html5", "HTML5 documents", argv)
def cli_latex(argv: Optional[List[str]] = None):
"""Cmdline entrypoint for converting MyST to LaTeX."""
_run_cli("latex", "LaTeX documents", argv)
def cli_xml(argv: Optional[List[str]] = None):
"""Cmdline entrypoint for converting MyST to XML."""
_run_cli("xml", "Docutils-native XML", argv)
def cli_pseudoxml(argv: Optional[List[str]] = None):
"""Cmdline entrypoint for converting MyST to pseudo-XML."""
_run_cli("pseudoxml", "pseudo-XML", argv)
