Add a format character %S to PyUnicode_FromFormat() that

embeds the result of PyObject_Unicode() into the resulting
unicode string.

diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index f2c5afa12563bacc6fe5d67c85da56b1f0b421c3..2fec095f1f46b1c0a82910a83e20d6cff20b199c 100644 (file)
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -504,14 +504,15 @@ PyUnicode_FromFormatV(const char *format, va_list vargs)
        count = vargs;
 #endif
 #endif
-       /* step 1: count the number of %R format specifications
-        * (we call PyObject_Repr() for these objects once during step 3
-        * and put the result in an array) */
+       /* step 1: count the number of %S/%R format specifications
+        * (we call PyObject_Unicode()/PyObject_Repr() for these objects
+        * once during step 3 and put the result in an array) */
        for (f = format; *f; f++) {
-               if (*f == '%' && *(f+1)=='R')
+               if (*f == '%' && (*(f+1)=='S' || *(f+1)=='R'))
                        ++callcount;
        }
-       /* step 2: allocate memory for the results of PyObject_Repr() calls */
+       /* step 2: allocate memory for the results of
+        * PyObject_Unicode()/PyObject_Repr() calls */
        if (callcount) {
                callresults = PyMem_Malloc(sizeof(PyObject *)*callcount);
                if (!callresults) {
@@ -558,6 +559,19 @@ PyUnicode_FromFormatV(const char *format, va_list vargs)
                                n += PyUnicode_GET_SIZE(obj);
                                break;
                        }
+                       case 'S':
+                       {
+                               PyObject *obj = va_arg(count, PyObject *);
+                               PyObject *str;
+                               assert(obj);
+                               str = PyObject_Unicode(obj);
+                               if (!str)
+                                       goto fail;
+                               n += PyUnicode_GET_SIZE(str);
+                               /* Remember the str and switch to the next slot */
+                               *callresult++ = str;
+                               break;
+                       }
                        case 'R':
                        {
                                PyObject *obj = va_arg(count, PyObject *);
@@ -683,6 +697,7 @@ PyUnicode_FromFormatV(const char *format, va_list vargs)
                                        *s++ = ucopy[upos++];
                                break;
                        }
+                       case 'S':
                        case 'R':
                        {
                                /* unused, since we already have the result */
@@ -692,9 +707,9 @@ PyUnicode_FromFormatV(const char *format, va_list vargs)
                                Py_ssize_t upos;
                                for (upos = 0; upos<usize;)
                                        *s++ = ucopy[upos++];
-                               /* We're done with the repr() => forget it */
+                               /* We're done with the unicode()/repr() => forget it */
                                Py_DECREF(*callresult);
-                               /* switch to next repr() result */
+                               /* switch to next unicode()/repr() result */
                                ++callresult;
                                break;
                        }