feature: add proper formula display in text and slides

renderer/fifty_ohm_html_renderer.py

@@ -3,6 +3,7 @@ from mistletoe import Document, HtmlRenderer
 
 from .comment import BlockComment
 from .dash import Dash
+from .formula import Formula
 from .halfwidth_spaces import HalfwidthSpaces
 from .include import Include
 from .morse import Morse
@@ -62,6 +63,7 @@ class FiftyOhmHtmlRenderer(HtmlRenderer):
             TableBody,
             Qso,
             Include,
+            Formula,
             *extras,
             **kwargs,
         )
@@ -324,3 +326,6 @@ class FiftyOhmHtmlRenderer(HtmlRenderer):
 
     def render_include(self, token):
         return self.include_handler(token.ident)
+
+    def render_formula(self, token):
+        return f"\n$${token.formula}$$\n"

renderer/formula.py

@@ -0,0 +1,27 @@
+import re
+
+from mistletoe.block_token import BlockToken
+
+
+class Formula(BlockToken):
+    r"""
+    Block token ("$ a \cdot b $").
+    Transfroms a line that contains only a formula enclosed in dollar signs into a Formula token.
+    """
+
+    @staticmethod
+    def start(line):
+        return re.match(r"^\s*\$[^$]+\$\s*$", line)
+
+    @classmethod
+    def check_interrupts_paragraph(cls, lines):
+        return cls.start(lines.peek())
+
+    @classmethod
+    def read(cls, lines):
+        line = next(lines)  # Consume the line with the formula
+        formula = re.match(r"^\s*\$([^$]+)\$\s*$", line).group(1)
+        return formula
+
+    def __init__(self, match):
+        self.formula = match