Improve visit_BoolOp implementation (#62)

* improve visit_Compare

* improve boolop

* support multiple comparators

Author: Yusuke Oda

src/latexify/latexify_visitor.py

@@ -268,24 +268,16 @@ def visit_Compare(self, node: ast.Compare, action):  # pylint: disable=invalid-n
         ops_rhs = [f" {o} {r}" for o, r in zip(ops, rhs)]
         return "{" + lhs + "".join(ops_rhs) + "}"
 
-    def visit_BoolOp(self, node, action):  # pylint: disable=invalid-name
-        logic_operator = (
-            r"\lor "
-            if isinstance(node.op, ast.Or)
-            else r"\land "
-            if isinstance(node.op, ast.And)
-            else r" \mathrm{unknown\_operator} "
-        )
-        # visit all the elements in the ast.If node recursively
-        return (
-            r"\left("
-            + self.visit(node.values[0])
-            + r"\right)"
-            + logic_operator
-            + r"\left("
-            + self.visit(node.values[1])
-            + r"\right)"
-        )
+    _bool_ops: ClassVar[dict[type[ast.boolop], str]] = {
+        ast.And: r"\land",
+        ast.Or: r"\lor",
+    }
+
+    def visit_BoolOp(self, node: ast.BoolOp, action):  # pylint: disable=invalid-name
+        """Visit a BoolOp node."""
+        values = [rf"\left( {self.visit(x)} \right)" for x in node.values]
+        op = f" {self._bool_ops[type(node.op)]} "
+        return "{" + op.join(values) + "}"
 
     def visit_If(self, node, action):  # pylint: disable=invalid-name
         """Visit an if node."""

src/latexify/latexify_visitor_test.py

@@ -44,3 +44,24 @@ def test_visit_compare(code: str, latex: str) -> None:
     tree = ast.parse(code).body[0].value
     assert isinstance(tree, ast.Compare)
     assert LatexifyVisitor().visit(tree) == latex
+
+
+@pytest.mark.parametrize(
+    "code,latex",
+    [
+        ("a and b", r"{\left( a \right) \land \left( b \right)}"),
+        (
+            "a and b and c",
+            r"{\left( a \right) \land \left( b \right) \land \left( c \right)}",
+        ),
+        ("a or b", r"{\left( a \right) \lor \left( b \right)}"),
+        (
+            "a or b or c",
+            r"{\left( a \right) \lor \left( b \right) \lor \left( c \right)}",
+        ),
+    ],
+)
+def test_visit_boolop(code: str, latex: str) -> None:
+    tree = ast.parse(code).body[0].value
+    assert isinstance(tree, ast.BoolOp)
+    assert LatexifyVisitor().visit(tree) == latex