Add ucsnarrow.c code.

1 files changed, 40 insertions, 0 deletions

diff --git a/numpy/core/src/ucsnarrow.c b/numpy/core/src/ucsnarrow.c
new file mode 100644
index 000000000..8960026d5
--- /dev/null
+++ b/numpy/core/src/ucsnarrow.c
@@ -0,0 +1,40 @@
+
+/* the ucs2 buffer must be large enough to hold 2*ucs4length characters
+   due to the use of surrogate pairs. 
+
+   The return value is the number of ucs2 bytes used-up which
+   is ucs4length + number of surrogate pairs found. 
+
+   values above 0xffff are converted to surrogate pairs. 
+ */
+static int
+PyUCS2Buffer_FromUCS4(Py_UNICODE *ucs2, PyArray_UCS4 *ucs4, int ucs4length)
+{
+        register int i;
+        int surrpairs = 0;
+        PyArray_UCS4 chr;
+        for (i=0; i<ucs4length; i++) {
+                chr = *ucs4++;
+                if (chr > 0xffff) {
+                        surrpairs++;
+                        chr -= 0x10000L;
+                        *ucs2++ = 0xD800 + (Py_UNICODE) (chr >> 10);
+                        *ucs2++ = 0xDC00 + (Py_UNICODE) (chr & 0x03FF);
+                }
+                else {
+                        *ucs2++ = (Py_UNICODE) (chr);
+                }
+        }
+        return ucs4length + surrpairs;
+}
+
+
+/* This converts a UCS2 buffer (from a Python unicode object)
+
+*/
+
+
+static int
+PyUCS2Buffer_AsUCS4(Py_UNICODE *ucs2, PyArray_UCS4 *ucs4, int ucs4length, int ucs2length)
+{
+}