Adding upstream version 2.1.0.upstream/2.1.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 330 insertions, 0 deletions

diff --git a/markdown_it/tree.py b/markdown_it/tree.py
new file mode 100644
index 0000000..09476b2
--- /dev/null
+++ b/markdown_it/tree.py
@@ -0,0 +1,330 @@
+"""A tree representation of a linear markdown-it token stream.
+
+This module is not part of upstream JavaScript markdown-it.
+"""
+from __future__ import annotations
+
+from collections.abc import Generator, Sequence
+import textwrap
+from typing import Any, NamedTuple, TypeVar, overload
+
+from .token import Token
+from .utils import _removesuffix
+
+
+class _NesterTokens(NamedTuple):
+    opening: Token
+    closing: Token
+
+
+_NodeType = TypeVar("_NodeType", bound="SyntaxTreeNode")
+
+
+class SyntaxTreeNode:
+    """A Markdown syntax tree node.
+
+    A class that can be used to construct a tree representation of a linear
+    `markdown-it-py` token stream.
+
+    Each node in the tree represents either:
+      - root of the Markdown document
+      - a single unnested `Token`
+      - a `Token` "_open" and "_close" token pair, and the tokens nested in
+          between
+    """
+
+    def __init__(
+        self, tokens: Sequence[Token] = (), *, create_root: bool = True
+    ) -> None:
+        """Initialize a `SyntaxTreeNode` from a token stream.
+
+        If `create_root` is True, create a root node for the document.
+        """
+        # Only nodes representing an unnested token have self.token
+        self.token: Token | None = None
+
+        # Only containers have nester tokens
+        self.nester_tokens: _NesterTokens | None = None
+
+        # Root node does not have self.parent
+        self._parent: Any = None
+
+        # Empty list unless a non-empty container, or unnested token that has
+        # children (i.e. inline or img)
+        self._children: list = []
+
+        if create_root:
+            self._set_children_from_tokens(tokens)
+            return
+
+        if not tokens:
+            raise ValueError(
+                "Can only create root from empty token sequence."
+                " Set `create_root=True`."
+            )
+        elif len(tokens) == 1:
+            inline_token = tokens[0]
+            if inline_token.nesting:
+                raise ValueError(
+                    "Unequal nesting level at the start and end of token stream."
+                )
+            self.token = inline_token
+            if inline_token.children:
+                self._set_children_from_tokens(inline_token.children)
+        else:
+            self.nester_tokens = _NesterTokens(tokens[0], tokens[-1])
+            self._set_children_from_tokens(tokens[1:-1])
+
+    def __repr__(self) -> str:
+        return f"{type(self).__name__}({self.type})"
+
+    @overload
+    def __getitem__(self: _NodeType, item: int) -> _NodeType:
+        ...
+
+    @overload
+    def __getitem__(self: _NodeType, item: slice) -> list[_NodeType]:
+        ...
+
+    def __getitem__(self: _NodeType, item: int | slice) -> _NodeType | list[_NodeType]:
+        return self.children[item]
+
+    def to_tokens(self: _NodeType) -> list[Token]:
+        """Recover the linear token stream."""
+
+        def recursive_collect_tokens(node: _NodeType, token_list: list[Token]) -> None:
+            if node.type == "root":
+                for child in node.children:
+                    recursive_collect_tokens(child, token_list)
+            elif node.token:
+                token_list.append(node.token)
+            else:
+                assert node.nester_tokens
+                token_list.append(node.nester_tokens.opening)
+                for child in node.children:
+                    recursive_collect_tokens(child, token_list)
+                token_list.append(node.nester_tokens.closing)
+
+        tokens: list[Token] = []
+        recursive_collect_tokens(self, tokens)
+        return tokens
+
+    @property
+    def children(self: _NodeType) -> list[_NodeType]:
+        return self._children
+
+    @children.setter
+    def children(self: _NodeType, value: list[_NodeType]) -> None:
+        self._children = value
+
+    @property
+    def parent(self: _NodeType) -> _NodeType | None:
+        return self._parent
+
+    @parent.setter
+    def parent(self: _NodeType, value: _NodeType | None) -> None:
+        self._parent = value
+
+    @property
+    def is_root(self) -> bool:
+        """Is the node a special root node?"""
+        return not (self.token or self.nester_tokens)
+
+    @property
+    def is_nested(self) -> bool:
+        """Is this node nested?.
+
+        Returns `True` if the node represents a `Token` pair and tokens in the
+        sequence between them, where `Token.nesting` of the first `Token` in
+        the pair is 1 and nesting of the other `Token` is -1.
+        """
+        return bool(self.nester_tokens)
+
+    @property
+    def siblings(self: _NodeType) -> Sequence[_NodeType]:
+        """Get siblings of the node.
+
+        Gets the whole group of siblings, including self.
+        """
+        if not self.parent:
+            return [self]
+        return self.parent.children
+
+    @property
+    def type(self) -> str:
+        """Get a string type of the represented syntax.
+
+        - "root" for root nodes
+        - `Token.type` if the node represents an unnested token
+        - `Token.type` of the opening token, with "_open" suffix stripped, if
+            the node represents a nester token pair
+        """
+        if self.is_root:
+            return "root"
+        if self.token:
+            return self.token.type
+        assert self.nester_tokens
+        return _removesuffix(self.nester_tokens.opening.type, "_open")
+
+    @property
+    def next_sibling(self: _NodeType) -> _NodeType | None:
+        """Get the next node in the sequence of siblings.
+
+        Returns `None` if this is the last sibling.
+        """
+        self_index = self.siblings.index(self)
+        if self_index + 1 < len(self.siblings):
+            return self.siblings[self_index + 1]
+        return None
+
+    @property
+    def previous_sibling(self: _NodeType) -> _NodeType | None:
+        """Get the previous node in the sequence of siblings.
+
+        Returns `None` if this is the first sibling.
+        """
+        self_index = self.siblings.index(self)
+        if self_index - 1 >= 0:
+            return self.siblings[self_index - 1]
+        return None
+
+    def _add_child(
+        self,
+        tokens: Sequence[Token],
+    ) -> None:
+        """Make a child node for `self`."""
+        child = type(self)(tokens, create_root=False)
+        child.parent = self
+        self.children.append(child)
+
+    def _set_children_from_tokens(self, tokens: Sequence[Token]) -> None:
+        """Convert the token stream to a tree structure and set the resulting
+        nodes as children of `self`."""
+        reversed_tokens = list(reversed(tokens))
+        while reversed_tokens:
+            token = reversed_tokens.pop()
+
+            if not token.nesting:
+                self._add_child([token])
+                continue
+            if token.nesting != 1:
+                raise ValueError("Invalid token nesting")
+
+            nested_tokens = [token]
+            nesting = 1
+            while reversed_tokens and nesting:
+                token = reversed_tokens.pop()
+                nested_tokens.append(token)
+                nesting += token.nesting
+            if nesting:
+                raise ValueError(f"unclosed tokens starting {nested_tokens[0]}")
+
+            self._add_child(nested_tokens)
+
+    def pretty(
+        self, *, indent: int = 2, show_text: bool = False, _current: int = 0
+    ) -> str:
+        """Create an XML style string of the tree."""
+        prefix = " " * _current
+        text = prefix + f"<{self.type}"
+        if not self.is_root and self.attrs:
+            text += " " + " ".join(f"{k}={v!r}" for k, v in self.attrs.items())
+        text += ">"
+        if show_text and not self.is_root and self.type == "text" and self.content:
+            text += "\n" + textwrap.indent(self.content, prefix + " " * indent)
+        for child in self.children:
+            text += "\n" + child.pretty(
+                indent=indent, show_text=show_text, _current=_current + indent
+            )
+        return text
+
+    def walk(
+        self: _NodeType, *, include_self: bool = True
+    ) -> Generator[_NodeType, None, None]:
+        """Recursively yield all descendant nodes in the tree starting at self.
+
+        The order mimics the order of the underlying linear token
+        stream (i.e. depth first).
+        """
+        if include_self:
+            yield self
+        for child in self.children:
+            yield from child.walk(include_self=True)
+
+    # NOTE:
+    # The values of the properties defined below directly map to properties
+    # of the underlying `Token`s. A root node does not translate to a `Token`
+    # object, so calling these property getters on a root node will raise an
+    # `AttributeError`.
+    #
+    # There is no mapping for `Token.nesting` because the `is_nested` property
+    # provides that data, and can be called on any node type, including root.
+
+    def _attribute_token(self) -> Token:
+        """Return the `Token` that is used as the data source for the
+        properties defined below."""
+        if self.token:
+            return self.token
+        if self.nester_tokens:
+            return self.nester_tokens.opening
+        raise AttributeError("Root node does not have the accessed attribute")
+
+    @property
+    def tag(self) -> str:
+        """html tag name, e.g. \"p\" """
+        return self._attribute_token().tag
+
+    @property
+    def attrs(self) -> dict[str, str | int | float]:
+        """Html attributes."""
+        return self._attribute_token().attrs
+
+    def attrGet(self, name: str) -> None | str | int | float:
+        """Get the value of attribute `name`, or null if it does not exist."""
+        return self._attribute_token().attrGet(name)
+
+    @property
+    def map(self) -> tuple[int, int] | None:
+        """Source map info. Format: `tuple[ line_begin, line_end ]`"""
+        map_ = self._attribute_token().map
+        if map_:
+            # Type ignore because `Token`s attribute types are not perfect
+            return tuple(map_)  # type: ignore
+        return None
+
+    @property
+    def level(self) -> int:
+        """nesting level, the same as `state.level`"""
+        return self._attribute_token().level
+
+    @property
+    def content(self) -> str:
+        """In a case of self-closing tag (code, html, fence, etc.), it
+        has contents of this tag."""
+        return self._attribute_token().content
+
+    @property
+    def markup(self) -> str:
+        """'*' or '_' for emphasis, fence string for fence, etc."""
+        return self._attribute_token().markup
+
+    @property
+    def info(self) -> str:
+        """fence infostring"""
+        return self._attribute_token().info
+
+    @property
+    def meta(self) -> dict:
+        """A place for plugins to store an arbitrary data."""
+        return self._attribute_token().meta
+
+    @property
+    def block(self) -> bool:
+        """True for block-level tokens, false for inline tokens."""
+        return self._attribute_token().block
+
+    @property
+    def hidden(self) -> bool:
+        """If it's true, ignore this element when rendering.
+        Used for tight lists to hide paragraphs."""
+        return self._attribute_token().hidden