Merge pull request #21 from asieira/i20_get_var

Better handling of encoding (resolves #20)

DESCRIPTION

@@ -1,6 +1,6 @@
 Package: SnakeCharmR
-Version: 1.0.2
-Date: 2016-05-20
+Version: 1.0.3
+Date: 2016-05-29
 Title: R and Python Integration
 Author: Alexandre Sieira, forked off of rPython by Carlos J. Gil Bellosta
 Maintainer: Alexandre Sieira <[email protected]>

NEWS.Rmd

@@ -10,6 +10,14 @@ knitr::opts_chunk$set(
   fig.retina = 2
 )
 ```
+# SnakeCharmR 1.0.3
+
+Taking measures to ensure SnakeCharmR will work properly on systems where the native encoding is not UTF-8:
+
+* Using Python API to check if variable is str/bytes or unicode and handling things correctly. In particular, when we read Python unicode values we flag the resulting R string as UTF-8 since that’s what we Python C API we are using will return;
+
+* Ensuring that Python code being executed is converted to UTF-8 and that the Python interpreter is made aware of that according to PEP 263.
+
 # SnakeCharmR 1.0.2
 
 Fixed linking and building errors on some platforms (such as Amazon Linux) by updating the

NEWS.md

@@ -1,5 +1,14 @@
 
 <!-- NEWS.md is generated from NEWS.Rmd. Please edit that file -->
+SnakeCharmR 1.0.3
+=================
+
+Taking measures to ensure SnakeCharmR will work properly on systems where the native encoding is not UTF-8:
+
+-   Using Python API to check if variable is str/bytes or unicode and handling things correctly. In particular, when we read Python unicode values we flag the resulting R string as UTF-8 since that’s what we Python C API we are using will return;
+
+-   Ensuring that Python code being executed is converted to UTF-8 and that the Python interpreter is made aware of that according to PEP 263.
+
 SnakeCharmR 1.0.2
 =================
 

R/misc.R

@@ -1,6 +1,6 @@
 .onAttach <- function(libname, pkgname) {
   packageStartupMessage(
-    c("SnakeCharmR v1.0.2 - R and Python Integration\n",
+    c("SnakeCharmR v1.0.3 - R and Python Integration\n",
       "Contribute and submit issues at https://github.com/asieira/SnakeCharmR")
   )
 }

src/python.cpp

@@ -27,19 +27,25 @@ void rcpp_Py_Finalize() {
 
 // [[Rcpp::export]]
 int rcpp_Py_run_code(String code) {
+  if (code.get_encoding() != "UTF-8")
+    code.set_encoding("UTF-8");
+  code.push_front("# -*- coding: utf-8 -*-\n");
   return PyRun_SimpleString(code.get_cstring());
 }
 
 // [[Rcpp::export]]
 String rcpp_Py_get_var(String varname) {
-  PyObject *result = PyDict_GetItemString(PyModule_GetDict(PyImport_AddModule("__main__")),
-                                          varname.get_cstring());
-  if (result == NULL)
+  PyObject *value = PyDict_GetItemString(PyModule_GetDict(PyImport_AddModule("__main__")),
+                                         varname.get_cstring());
+  if (value == NULL)
     return NA_STRING;
 
-#if PY_MAJOR_VERSION >= 3
-  return String(PyBytes_AS_STRING(PyUnicode_AsUTF8String(result)));
-#else
-  return String(PyString_AS_STRING(result));
-#endif
+  if (PyUnicode_Check(value)) {
+    String retval(PyString_AS_STRING(PyUnicode_AsUTF8String(value)));
+    retval.set_encoding("UTF-8");
+    return retval;
+  } else if (PyString_Check(value))
+    return String(PyString_AS_STRING(value));
+  else
+    throw std::invalid_argument("variable is not a string");
 }

tests/testthat/test-rcpp-get.R

@@ -0,0 +1,15 @@
+# context("Rcpp get of string/bytes and unicode types")
+# 
+# test_that("we can read string//bytes and unicode", {
+#   py.exec("_test_var = 'blah'")
+#   expect_equal(rcpp_Py_get_var("_test_var"), "blah")
+# 
+#   py.exec("_test_var = u'blah'")
+#   expect_equal(rcpp_Py_get_var("_test_var"), "blah")
+#   
+#   py.exec("_test_var = u'áéíóú'")
+#   expect_equal(rcpp_Py_get_var("_test_var"), "áéíóú")
+#   
+#   py.exec("_test_var = 1")
+#   expect_error(rcpp_Py_get_var("_test_var"), "variable is not a string")
+# })