modularized
This commit is contained in:
randogoth
parent
4e754528c0
commit
de6e99c24a
5 changed files with 1416 additions and 1217 deletions
542
markdown_parser.py
Normal file
542
markdown_parser.py
Normal file
|
|
@ -0,0 +1,542 @@
|
|||
from __future__ import annotations
|
||||
|
||||
import re
|
||||
from typing import Iterable, Iterator, List, Optional, Union
|
||||
|
||||
from md_types import (
|
||||
BlockEvent,
|
||||
BlockKind,
|
||||
BlockQuotePayload,
|
||||
BlockStyle,
|
||||
CodeBlockPayload,
|
||||
HeadingPayload,
|
||||
ListItemPayload,
|
||||
ParagraphPayload,
|
||||
StyleSpec,
|
||||
StyleUpdateEvent,
|
||||
)
|
||||
|
||||
|
||||
HEADING_PATTERN = re.compile(r"^(#{1,6})\s+(.*)$")
|
||||
ORDERED_LIST_PATTERN = re.compile(r"^(\s*)(\d+\.)(\s+)(.*)$")
|
||||
UNORDERED_LIST_PATTERN = re.compile(r"^(\s*)([*+-])(\s+)(.*)$")
|
||||
BLOCKQUOTE_PATTERN = re.compile(r"^\s{0,3}>(.*)$")
|
||||
HORIZONTAL_RULE_PATTERN = re.compile(r"^\s*([-*_])(?:\s*\1){2,}\s*$")
|
||||
INLINE_PARA_RE = re.compile(r"^\s*<p\b([^>]*)>(.*?)</p>\s*$", re.IGNORECASE)
|
||||
PARA_OPEN_RE = re.compile(r"^\s*<p\b([^>]*)>\s*$", re.IGNORECASE)
|
||||
PARA_CLOSE_RE = re.compile(r"^\s*</p>\s*$", re.IGNORECASE)
|
||||
MMD_ATTR_LINE_RE = re.compile(r"^\{\s*:(.+)\}\s*$")
|
||||
MMD_ATTR_TAIL_RE = re.compile(r"(.*?)\s*\{\s*:(.+?)\}\s*$")
|
||||
|
||||
|
||||
class MarkdownParser:
|
||||
def __init__(self, base_style: BlockStyle) -> None:
|
||||
self._base_style = base_style
|
||||
self._style_stack: List[BlockStyle] = [self._make_base_style()]
|
||||
self._paragraph_style_spec: Optional[StyleSpec] = None
|
||||
self._pending_block_style_spec: Optional[StyleSpec] = None
|
||||
self._last_stylable_block: bool = False
|
||||
|
||||
def parse(self, lines: Iterable[str]) -> Iterator[Union[BlockEvent, StyleUpdateEvent]]:
|
||||
self._reset_state()
|
||||
iterator = iter(lines)
|
||||
in_code_block = False
|
||||
code_lines: List[str] = []
|
||||
indented_code_lines: List[str] = []
|
||||
current_paragraph: List[str] = []
|
||||
|
||||
for raw_line in iterator:
|
||||
line = raw_line.rstrip("\n")
|
||||
|
||||
if in_code_block:
|
||||
if line.strip().startswith("```"):
|
||||
event = self._flush_code_block(code_lines)
|
||||
if event is not None:
|
||||
yield event
|
||||
code_lines = []
|
||||
in_code_block = False
|
||||
else:
|
||||
code_lines.append(line)
|
||||
continue
|
||||
|
||||
if indented_code_lines:
|
||||
if line.startswith(" "):
|
||||
indented_code_lines.append(line[4:])
|
||||
continue
|
||||
if not line.strip():
|
||||
event = self._flush_code_block(indented_code_lines)
|
||||
if event is not None:
|
||||
yield event
|
||||
indented_code_lines = []
|
||||
else:
|
||||
event = self._flush_code_block(indented_code_lines)
|
||||
if event is not None:
|
||||
yield event
|
||||
indented_code_lines = []
|
||||
|
||||
inline_para = INLINE_PARA_RE.match(line.strip())
|
||||
if inline_para:
|
||||
event = self._flush_paragraph(current_paragraph)
|
||||
if event is not None:
|
||||
yield event
|
||||
current_paragraph = []
|
||||
spec = self._style_spec_from_html_attributes(inline_para.group(1) or "")
|
||||
self._push_style(spec)
|
||||
content = inline_para.group(2)
|
||||
if content:
|
||||
current_paragraph.append(content)
|
||||
event = self._flush_paragraph(current_paragraph)
|
||||
if event is not None:
|
||||
yield event
|
||||
current_paragraph = []
|
||||
self._pop_style()
|
||||
continue
|
||||
|
||||
open_para = PARA_OPEN_RE.match(line)
|
||||
if open_para:
|
||||
spec = self._style_spec_from_html_attributes(open_para.group(1) or "")
|
||||
self._push_style(spec)
|
||||
continue
|
||||
|
||||
close_para = PARA_CLOSE_RE.match(line)
|
||||
if close_para:
|
||||
event = self._flush_paragraph(current_paragraph)
|
||||
if event is not None:
|
||||
yield event
|
||||
current_paragraph = []
|
||||
self._paragraph_style_spec = None
|
||||
self._pop_style()
|
||||
continue
|
||||
|
||||
stripped = line.strip()
|
||||
attr_match = MMD_ATTR_LINE_RE.match(stripped)
|
||||
if attr_match:
|
||||
spec = self._parse_style_spec_from_tokens(attr_match.group(1))
|
||||
if spec:
|
||||
if current_paragraph:
|
||||
self._paragraph_style_spec = self._merge_specs(self._paragraph_style_spec, spec)
|
||||
elif self._last_stylable_block:
|
||||
yield StyleUpdateEvent(spec)
|
||||
else:
|
||||
self._pending_block_style_spec = self._merge_specs(self._pending_block_style_spec, spec)
|
||||
continue
|
||||
|
||||
if line.strip().startswith("```"):
|
||||
event = self._flush_paragraph(current_paragraph)
|
||||
if event is not None:
|
||||
yield event
|
||||
current_paragraph = []
|
||||
in_code_block = True
|
||||
code_lines = []
|
||||
continue
|
||||
|
||||
if line.startswith(" "):
|
||||
event = self._flush_paragraph(current_paragraph)
|
||||
if event is not None:
|
||||
yield event
|
||||
current_paragraph = []
|
||||
indented_code_lines = [line[4:]]
|
||||
continue
|
||||
|
||||
heading_match = HEADING_PATTERN.match(line)
|
||||
if heading_match:
|
||||
event = self._flush_paragraph(current_paragraph)
|
||||
if event is not None:
|
||||
yield event
|
||||
current_paragraph = []
|
||||
level = len(heading_match.group(1))
|
||||
heading_text = heading_match.group(2).strip()
|
||||
heading_text, inline_spec = self._extract_trailing_attr(heading_text)
|
||||
combined_spec = self._merge_specs(self._pending_block_style_spec, inline_spec)
|
||||
style = self._combine_styles(self._current_style(), combined_spec)
|
||||
self._pending_block_style_spec = None
|
||||
self._last_stylable_block = True
|
||||
yield BlockEvent(
|
||||
kind=BlockKind.HEADING,
|
||||
payload=HeadingPayload(level=level, text=heading_text),
|
||||
style=style,
|
||||
stylable=True,
|
||||
)
|
||||
continue
|
||||
|
||||
if HORIZONTAL_RULE_PATTERN.match(line):
|
||||
event = self._flush_paragraph(current_paragraph)
|
||||
if event is not None:
|
||||
yield event
|
||||
current_paragraph = []
|
||||
self._last_stylable_block = False
|
||||
yield BlockEvent(
|
||||
kind=BlockKind.HORIZONTAL_RULE,
|
||||
payload=None,
|
||||
style=self._clone_style(),
|
||||
stylable=False,
|
||||
)
|
||||
continue
|
||||
|
||||
if BLOCKQUOTE_PATTERN.match(line):
|
||||
event = self._flush_paragraph(current_paragraph)
|
||||
if event is not None:
|
||||
yield event
|
||||
current_paragraph = []
|
||||
quote_event = self._parse_blockquote(line)
|
||||
if quote_event is not None:
|
||||
yield quote_event
|
||||
continue
|
||||
|
||||
if UNORDERED_LIST_PATTERN.match(line) or ORDERED_LIST_PATTERN.match(line):
|
||||
event = self._flush_paragraph(current_paragraph)
|
||||
if event is not None:
|
||||
yield event
|
||||
current_paragraph = []
|
||||
list_event = self._parse_list_line(line)
|
||||
if list_event is not None:
|
||||
yield list_event
|
||||
continue
|
||||
|
||||
if not line.strip():
|
||||
event = self._flush_paragraph(current_paragraph)
|
||||
if event is not None:
|
||||
yield event
|
||||
yield BlockEvent(
|
||||
kind=BlockKind.BLANK_LINE,
|
||||
payload=None,
|
||||
style=self._clone_style(),
|
||||
stylable=False,
|
||||
)
|
||||
current_paragraph = []
|
||||
continue
|
||||
|
||||
current_paragraph.append(line)
|
||||
|
||||
event = self._flush_paragraph(current_paragraph)
|
||||
if event is not None:
|
||||
yield event
|
||||
if in_code_block:
|
||||
final_event = self._flush_code_block(code_lines)
|
||||
if final_event is not None:
|
||||
yield final_event
|
||||
if indented_code_lines:
|
||||
final_event = self._flush_code_block(indented_code_lines)
|
||||
if final_event is not None:
|
||||
yield final_event
|
||||
|
||||
def _reset_state(self) -> None:
|
||||
self._style_stack = [self._make_base_style()]
|
||||
self._paragraph_style_spec = None
|
||||
self._pending_block_style_spec = None
|
||||
self._last_stylable_block = False
|
||||
|
||||
def _flush_paragraph(self, paragraph_lines: List[str]) -> Optional[BlockEvent]:
|
||||
if not paragraph_lines:
|
||||
return None
|
||||
text = " ".join(line.strip() for line in paragraph_lines)
|
||||
combined_spec = self._merge_specs(self._pending_block_style_spec, self._paragraph_style_spec)
|
||||
style = self._combine_styles(self._current_style(), combined_spec)
|
||||
|
||||
paragraph_lines.clear()
|
||||
self._paragraph_style_spec = None
|
||||
self._pending_block_style_spec = None
|
||||
self._last_stylable_block = True
|
||||
return BlockEvent(
|
||||
kind=BlockKind.PARAGRAPH,
|
||||
payload=ParagraphPayload(text=text),
|
||||
style=style,
|
||||
stylable=True,
|
||||
)
|
||||
|
||||
def _flush_code_block(self, code_lines: List[str]) -> Optional[BlockEvent]:
|
||||
if not code_lines:
|
||||
return None
|
||||
lines = code_lines.copy()
|
||||
code_lines.clear()
|
||||
self._last_stylable_block = False
|
||||
return BlockEvent(
|
||||
kind=BlockKind.CODE_BLOCK,
|
||||
payload=CodeBlockPayload(lines=lines),
|
||||
style=self._clone_style(),
|
||||
stylable=False,
|
||||
)
|
||||
|
||||
def _parse_blockquote(self, line: str) -> Optional[BlockEvent]:
|
||||
content = line
|
||||
depth = 0
|
||||
while content.lstrip().startswith(">"):
|
||||
depth += 1
|
||||
content = content.lstrip()[1:]
|
||||
text = content.lstrip()
|
||||
self._last_stylable_block = False
|
||||
return BlockEvent(
|
||||
kind=BlockKind.BLOCKQUOTE,
|
||||
payload=BlockQuotePayload(depth=max(1, depth), text=text),
|
||||
style=self._clone_style(),
|
||||
stylable=False,
|
||||
)
|
||||
|
||||
def _parse_list_line(self, line: str) -> Optional[BlockEvent]:
|
||||
ordered = ORDERED_LIST_PATTERN.match(line)
|
||||
unordered = UNORDERED_LIST_PATTERN.match(line)
|
||||
if ordered:
|
||||
indent, marker, spacing, rest = ordered.groups()
|
||||
ordered_flag = True
|
||||
elif unordered:
|
||||
indent, marker, spacing, rest = unordered.groups()
|
||||
ordered_flag = False
|
||||
else:
|
||||
return None
|
||||
self._last_stylable_block = False
|
||||
return BlockEvent(
|
||||
kind=BlockKind.LIST_ITEM,
|
||||
payload=ListItemPayload(
|
||||
indent=indent,
|
||||
marker=marker,
|
||||
spacing=spacing,
|
||||
text=rest,
|
||||
ordered=ordered_flag,
|
||||
),
|
||||
style=self._clone_style(),
|
||||
stylable=False,
|
||||
)
|
||||
|
||||
def _make_base_style(self) -> BlockStyle:
|
||||
return BlockStyle(
|
||||
align=self._base_style.align,
|
||||
margin_left=self._base_style.margin_left,
|
||||
margin_right=self._base_style.margin_right,
|
||||
)
|
||||
|
||||
def _current_style(self) -> BlockStyle:
|
||||
return self._style_stack[-1]
|
||||
|
||||
def _clone_style(self) -> BlockStyle:
|
||||
style = self._current_style()
|
||||
return BlockStyle(
|
||||
align=style.align,
|
||||
margin_left=style.margin_left,
|
||||
margin_right=style.margin_right,
|
||||
)
|
||||
|
||||
def _push_style(self, spec: Optional[StyleSpec]) -> None:
|
||||
base = self._current_style()
|
||||
self._style_stack.append(self._combine_styles(base, spec))
|
||||
|
||||
def _pop_style(self) -> None:
|
||||
if len(self._style_stack) > 1:
|
||||
self._style_stack.pop()
|
||||
|
||||
def _combine_styles(self, base: BlockStyle, spec: Optional[StyleSpec]) -> BlockStyle:
|
||||
if spec is None:
|
||||
return BlockStyle(
|
||||
align=base.align,
|
||||
margin_left=base.margin_left,
|
||||
margin_right=base.margin_right,
|
||||
)
|
||||
return BlockStyle(
|
||||
align=spec.align or base.align,
|
||||
margin_left=spec.margin_left if spec.margin_left is not None else base.margin_left,
|
||||
margin_right=spec.margin_right if spec.margin_right is not None else base.margin_right,
|
||||
)
|
||||
|
||||
def _merge_specs(self, first: Optional[StyleSpec], second: Optional[StyleSpec]) -> Optional[StyleSpec]:
|
||||
if first is None and second is None:
|
||||
return None
|
||||
if first is None:
|
||||
return second
|
||||
if second is None:
|
||||
return first
|
||||
return StyleSpec(
|
||||
align=second.align or first.align,
|
||||
margin_left=second.margin_left if second.margin_left is not None else first.margin_left,
|
||||
margin_right=second.margin_right if second.margin_right is not None else first.margin_right,
|
||||
)
|
||||
|
||||
def _style_spec_from_html_attributes(self, attributes: str) -> Optional[StyleSpec]:
|
||||
if not attributes:
|
||||
return None
|
||||
attr_pattern = re.compile(r"([\w:-]+)\s*=\s*(\".*?\"|'.*?'|\S+)")
|
||||
attr_map = {name.lower(): value.strip().strip("\"'") for name, value in attr_pattern.findall(attributes)}
|
||||
|
||||
spec: Optional[StyleSpec] = None
|
||||
align_value = attr_map.get("align")
|
||||
if align_value:
|
||||
normalized = self._normalize_align(align_value)
|
||||
if normalized:
|
||||
spec = self._merge_specs(spec, StyleSpec(align=normalized))
|
||||
|
||||
style_value = attr_map.get("style")
|
||||
if style_value:
|
||||
css_spec = self._style_spec_from_css(style_value)
|
||||
spec = self._merge_specs(spec, css_spec)
|
||||
return spec
|
||||
|
||||
def _style_spec_from_css(self, css: str) -> Optional[StyleSpec]:
|
||||
spec = StyleSpec()
|
||||
changed = False
|
||||
for declaration in css.split(";"):
|
||||
if ":" not in declaration:
|
||||
continue
|
||||
name, value = declaration.split(":", 1)
|
||||
name = name.strip().lower()
|
||||
value = value.strip()
|
||||
if not value:
|
||||
continue
|
||||
if name == "text-align":
|
||||
normalized = self._normalize_align(value)
|
||||
if normalized:
|
||||
spec.align = normalized
|
||||
changed = True
|
||||
elif name == "margin":
|
||||
left, right, auto_center = self._parse_css_margin_shorthand(value)
|
||||
if left is not None:
|
||||
spec.margin_left = left
|
||||
changed = True
|
||||
if right is not None:
|
||||
spec.margin_right = right
|
||||
changed = True
|
||||
if auto_center:
|
||||
spec.align = "center"
|
||||
changed = True
|
||||
elif name == "margin-left":
|
||||
parsed = self._parse_space_value(value)
|
||||
if parsed is not None:
|
||||
spec.margin_left = parsed
|
||||
changed = True
|
||||
elif value.lower() == "auto":
|
||||
spec.align = spec.align or "center"
|
||||
changed = True
|
||||
elif name == "margin-right":
|
||||
parsed = self._parse_space_value(value)
|
||||
if parsed is not None:
|
||||
spec.margin_right = parsed
|
||||
changed = True
|
||||
elif value.lower() == "auto":
|
||||
spec.align = spec.align or "center"
|
||||
changed = True
|
||||
return spec if changed else None
|
||||
|
||||
def _parse_style_spec_from_tokens(self, token_str: str) -> Optional[StyleSpec]:
|
||||
tokens = re.split(r"\s+", token_str.strip())
|
||||
spec = StyleSpec()
|
||||
changed = False
|
||||
for token in tokens:
|
||||
token = token.strip()
|
||||
if not token:
|
||||
continue
|
||||
if token.startswith("."):
|
||||
align = self._class_to_align(token[1:])
|
||||
if align:
|
||||
spec.align = align
|
||||
changed = True
|
||||
continue
|
||||
if "=" in token:
|
||||
key, value = token.split("=", 1)
|
||||
key = key.strip().lower().lstrip(".")
|
||||
value = value.strip().strip("\"'")
|
||||
if key in {"align", "text-align"}:
|
||||
normalized = self._normalize_align(value)
|
||||
if normalized:
|
||||
spec.align = normalized
|
||||
changed = True
|
||||
elif key in {"margin", "margin-left", "margin-right"}:
|
||||
if key == "margin":
|
||||
left, right, auto_center = self._parse_css_margin_shorthand(value)
|
||||
if left is not None:
|
||||
spec.margin_left = left
|
||||
changed = True
|
||||
if right is not None:
|
||||
spec.margin_right = right
|
||||
changed = True
|
||||
if auto_center:
|
||||
spec.align = "center"
|
||||
changed = True
|
||||
elif key == "margin-left":
|
||||
parsed = self._parse_space_value(value)
|
||||
if parsed is not None:
|
||||
spec.margin_left = parsed
|
||||
changed = True
|
||||
elif value.lower() == "auto":
|
||||
spec.align = spec.align or "center"
|
||||
changed = True
|
||||
elif key == "margin-right":
|
||||
parsed = self._parse_space_value(value)
|
||||
if parsed is not None:
|
||||
spec.margin_right = parsed
|
||||
changed = True
|
||||
elif value.lower() == "auto":
|
||||
spec.align = spec.align or "center"
|
||||
changed = True
|
||||
continue
|
||||
align = self._normalize_align(token)
|
||||
if align:
|
||||
spec.align = align
|
||||
changed = True
|
||||
return spec if changed else None
|
||||
|
||||
def _parse_css_margin_shorthand(self, value: str):
|
||||
parts = [part for part in re.split(r"\s+", value.strip()) if part]
|
||||
if not parts:
|
||||
return None, None, False
|
||||
|
||||
values: List[Optional[int]] = []
|
||||
autos: List[bool] = []
|
||||
for part in parts:
|
||||
if part.lower() == "auto":
|
||||
values.append(None)
|
||||
autos.append(True)
|
||||
else:
|
||||
parsed = self._parse_space_value(part)
|
||||
values.append(parsed)
|
||||
autos.append(False)
|
||||
|
||||
left_auto = False
|
||||
right_auto = False
|
||||
if len(values) == 1:
|
||||
left = right = values[0]
|
||||
left_auto = right_auto = autos[0]
|
||||
elif len(values) == 2:
|
||||
left = right = values[1]
|
||||
left_auto = right_auto = autos[1]
|
||||
elif len(values) == 3:
|
||||
left = right = values[1]
|
||||
left_auto = right_auto = autos[1]
|
||||
else:
|
||||
right = values[1]
|
||||
left = values[3]
|
||||
right_auto = autos[1]
|
||||
left_auto = autos[3]
|
||||
auto_center = left_auto and right_auto
|
||||
return left, right, auto_center
|
||||
|
||||
def _parse_space_value(self, value: str) -> Optional[int]:
|
||||
match = re.match(r"(-?\d+(?:\.\d+)?)", value.strip())
|
||||
if not match:
|
||||
return None
|
||||
number = float(match.group(1))
|
||||
return max(0, int(round(number)))
|
||||
|
||||
def _normalize_align(self, value: str) -> Optional[str]:
|
||||
normalized = value.strip().lower()
|
||||
mapping = {
|
||||
"centre": "center",
|
||||
"center": "center",
|
||||
"left": "left",
|
||||
"right": "right",
|
||||
}
|
||||
return mapping.get(normalized)
|
||||
|
||||
def _class_to_align(self, class_name: str) -> Optional[str]:
|
||||
name = class_name.strip().lower().lstrip(".")
|
||||
if name in {"center", "text-center", "align-center"}:
|
||||
return "center"
|
||||
if name in {"left", "text-left", "align-left"}:
|
||||
return "left"
|
||||
if name in {"right", "text-right", "align-right"}:
|
||||
return "right"
|
||||
return None
|
||||
|
||||
def _extract_trailing_attr(self, text: str):
|
||||
match = MMD_ATTR_TAIL_RE.match(text)
|
||||
if not match:
|
||||
return text, None
|
||||
clean_text = match.group(1).rstrip()
|
||||
spec = self._parse_style_spec_from_tokens(match.group(2))
|
||||
return clean_text, spec
|
||||
Loading…
Add table
Add a link
Reference in a new issue