fix: matrix not rendor in docx

app/services/converter.py

@@ -122,12 +122,18 @@ class Converter:
         # Convert matrix environments for better Word rendering
         cleaned_md = self._convert_matrix_environments(cleaned_md)
 
+        # Fix array environment column specifiers (remove spaces)
+        cleaned_md = self._fix_array_column_specifiers(cleaned_md)
+
         # Fix brace spacing for equation systems
         cleaned_md = self._fix_brace_spacing(cleaned_md)
 
         # Convert cases and aligned environments
         cleaned_md = self._convert_special_environments(cleaned_md)
 
+        # Handle LaTeX \tag{} commands for equation numbering
+        cleaned_md = self._convert_tag_commands(cleaned_md)
+
         return cleaned_md
 
     def _convert_matrix_environments(self, md_text: str) -> str:
@@ -153,6 +159,37 @@ class Converter:
 
         return md_text
 
+    def _fix_array_column_specifiers(self, md_text: str) -> str:
+        """Fix array environment column specifiers by removing spaces.
+
+        Pandoc's OMML converter doesn't accept spaces between column alignment
+        specifiers in array environments. This converts patterns like
+        {c c c c} to {cccc}.
+
+        Args:
+            md_text: Markdown text with LaTeX formulas.
+
+        Returns:
+            Markdown text with fixed array column specifiers.
+        """
+
+        def remove_spaces_in_specifier(match: re.Match) -> str:
+            """Remove spaces from column specifier."""
+            specifier = match.group(1)
+            # Remove all spaces from the specifier
+            specifier_no_spaces = re.sub(r"\s+", "", specifier)
+            return f"\\begin{{array}}{{{specifier_no_spaces}}}"
+
+        # Match \begin{array}{...} and remove spaces in the column specifier
+        # Pattern: \begin{array}{c c c ...} -> \begin{array}{ccc...}
+        md_text = re.sub(
+            r"\\begin\{array\}\{([^}]+)\}",
+            remove_spaces_in_specifier,
+            md_text,
+        )
+
+        return md_text
+
     def _fix_brace_spacing(self, md_text: str) -> str:
         """Fix spacing issues with braces in equation systems.
 
@@ -218,6 +255,41 @@ class Converter:
 
         return md_text
 
+    def _convert_tag_commands(self, md_text: str) -> str:
+        """Convert LaTeX \\tag{} commands to Word-compatible format.
+
+        The \\tag{} command is not supported in Word OMML format, so we convert it to
+        use simple spacing (\quad) to push the equation number to the right side.
+        The tag remains inside the formula for better compatibility.
+
+        Args:
+            md_text: Markdown text containing LaTeX formulas with \\tag{}.
+
+        Returns:
+            Markdown text with \\tag{} commands converted to spacing format.
+        """
+
+        def convert_tag(match: re.Match) -> str:
+            """Convert a single \\tag{} command within a formula."""
+            formula_content = match.group(1)
+            tag_content = match.group(2)
+
+            # Replace \tag{...} with \quad (...) to push the number to the right
+            # Keep it inside the formula for better Word compatibility
+            return f"$${formula_content} \\quad ({tag_content})$$"
+
+        # Match display formulas ($$...$$) containing \\tag{...}
+        # Pattern: $$...content...\\tag {?...}...$$
+        # Allow optional space between \tag and {
+        md_text = re.sub(
+            r"\$\$(.*?)\\tag\s*\{([^}]+)\}\s*\$\$",
+            convert_tag,
+            md_text,
+            flags=re.DOTALL,
+        )
+
+        return md_text
+
     def export_to_file(self, md_text: str, export_type: ExportType = "docx") -> bytes:
         """Export markdown to docx or pdf file.