BigUpdate

md2gost/extended_markdown/table.py

@@ -0,0 +1,157 @@
+import re
+
+from marko import block
+from marko.ext.gfm.elements import TableCell as GfmTableCell
+
+
+MERGE_V_MARKERS = {"^", "^^"}
+MERGE_H_MARKERS = {">", ">>"}
+
+
+class TableCell(GfmTableCell):
+    """GFM table cell with rowspan/colspan continue markers (^ / >)."""
+
+    def __init__(self, text: str, position: int | None = None) -> None:
+        stripped = text.strip()
+        self.merge_v = "none"
+        self.merge_h = "none"
+        if stripped in MERGE_V_MARKERS:
+            self.merge_v = "continue"
+            text = " "
+        elif stripped in MERGE_H_MARKERS:
+            self.merge_h = "continue"
+            text = " "
+        super().__init__(text, position)
+
+
+class TableRow(block.BlockElement):
+    """A table row element."""
+
+    splitter = re.compile(r"\s*(?<!\\)\|\s*")
+    delimiter = re.compile(r":?-+:?")
+    virtual = True
+    _cells = None
+    _is_delimiter = False
+
+    def __init__(self, cells):
+        self.children = cells
+
+    @classmethod
+    def match(cls, source):
+        line = source.next_line()
+        if not line or not re.match(r" {,3}\S", line):
+            return False
+        parts = cls.splitter.split(line.strip())
+        if parts and not parts[0]:
+            parts.pop(0)
+        if parts and not parts[-1]:
+            parts.pop()
+        if len(parts) < 1:
+            return False
+        cls._cells = parts
+        cls._is_delimiter = all(cls.delimiter.match(cell) for cell in parts)
+        return True
+
+    @classmethod
+    def parse(cls, source):
+        source.consume()
+        parent = source.state
+        cells = cls._cells[:]
+        if len(cells) < parent._num_of_cols:
+            cells.extend("" for _ in range(parent._num_of_cols - len(cells)))
+        elif len(cells) > parent._num_of_cols:
+            cells = cells[: parent._num_of_cols]
+        cells = [TableCell(cell) for cell in cells]
+        if parent.children:
+            for head, cell in zip(parent.children[0].children, cells):
+                cell.align = head.align
+        return cells
+
+
+class Table(block.BlockElement):
+    """A table element."""
+
+    _num_of_cols = None
+    _prefix = ""
+    override = True
+
+    @classmethod
+    def match(cls, source):
+        source.anchor()
+        if TableRow.match(source) and not TableRow._is_delimiter:
+            if not TableRow.splitter.search(source.next_line()):
+                return False
+            source.pos = source.match.end()
+            num_of_cols = len(TableRow._cells)
+            if (
+                TableRow.match(source)
+                and TableRow._is_delimiter
+                and num_of_cols == len(TableRow._cells)
+            ):
+                cls._num_of_cols = num_of_cols
+                lens = [len(x) for x in TableRow._cells]
+                proportions = [x/sum(lens) for x in lens]
+                TableRow.proportions = proportions
+                source.reset()
+                return True
+        source.reset()
+        return False
+
+    @classmethod
+    def parse(cls, source):
+        rv = cls()
+        rv._num_of_cols = cls._num_of_cols
+        rv.children = []
+        with source.under_state(rv):
+            TableRow.match(source)
+            header = TableRow(TableRow.parse(source))
+            rv.children.append(header)
+            TableRow.match(source)
+            delimiters = TableRow._cells
+            source.consume()
+            for d, th in zip(delimiters, header.children):
+                stripped_d = d.strip()
+                th.header = True
+                if stripped_d[0] == ":" and stripped_d[-1] == ":":
+                    th.align = "center"
+                elif stripped_d[0] == ":":
+                    th.align = "left"
+                elif stripped_d[-1] == ":":
+                    th.align = "right"
+            while not source.exhausted:
+                for e in source.parser._build_block_element_list():
+                    if issubclass(e, (Table, block.Paragraph)):
+                        continue
+                    if e.match(source):
+                        break
+                else:
+                    if TableRow.match(source):
+                        rv.children.append(TableRow(TableRow.parse(source)))
+                        continue
+                break
+        _resolve_merge_restarts(rv)
+        return rv
+
+
+def _resolve_merge_restarts(table: Table) -> None:
+    """Mark restart cells that start a vertical/horizontal merge group."""
+    rows = table.children
+    if not rows:
+        return
+    n_cols = table._num_of_cols
+    n_rows = len(rows)
+
+    for col in range(n_cols):
+        for row in range(n_rows):
+            cell = rows[row].children[col]
+            if cell.merge_v != "continue":
+                # restart if any continue below until next non-continue
+                if row + 1 < n_rows and rows[row + 1].children[col].merge_v == "continue":
+                    cell.merge_v = "restart"
+
+    for row in range(n_rows):
+        for col in range(n_cols):
+            cell = rows[row].children[col]
+            if cell.merge_h != "continue":
+                if col + 1 < n_cols and rows[row].children[col + 1].merge_h == "continue":
+                    cell.merge_h = "restart"