From d5718ef98a3158f8921f1cdcd920f3f6d0f00afd Mon Sep 17 00:00:00 2001
From: Marcin Wojdyr <wojdyr@gmail.com>
Date: Mon, 24 May 2021 20:14:46 +0200
Subject: [PATCH] py: tao::pegtl::parse_error -> ValueError (#119)

---
 python/gemmi.cpp  | 3 +++
 tests/test_cif.py | 4 ++++
 2 files changed, 7 insertions(+)

diff --git a/python/gemmi.cpp b/python/gemmi.cpp
index 5d578fc06..5dc4ba5bc 100644
--- a/python/gemmi.cpp
+++ b/python/gemmi.cpp
@@ -9,6 +9,7 @@
 #include "gemmi/small.hpp"    // for SmallStructure
 #include "gemmi/interop.hpp"  // for atom_to_site, mx_to_sx_structure
 #include "gemmi/bessel.hpp"   // for bessel_i1_over_i0
+#include "gemmi/third_party/tao/pegtl/parse_error.hpp" // for parse_error
 
 namespace py = pybind11;
 
@@ -88,6 +89,8 @@ PYBIND11_MODULE(gemmi, mg) {
     } catch (const std::system_error &e) {
       const int errornum = e.code().value();
       PyErr_SetObject(PyExc_IOError, py::make_tuple(errornum, e.what()).ptr());
+    } catch (const tao::pegtl::parse_error &e) {
+      PyErr_SetString(PyExc_ValueError, e.what());
     }
   });
 
diff --git a/tests/test_cif.py b/tests/test_cif.py
index 7b4520e61..317764a63 100755
--- a/tests/test_cif.py
+++ b/tests/test_cif.py
@@ -243,6 +243,10 @@ def test_file_not_found(self):
         with self.assertRaises(IOError):
             cif.read('file-that-does-not-exist.cif')
 
+    def test_syntax_error(self):
+        with self.assertRaises(ValueError):
+            cif.read_string('data_a boom')
+
     def test_line_endings(self):
         lines = ['data_a', '_a_field', ';', 'text line', '2nd line', ';']
         for eol in ('\r\n', '\n'):