Part of review

Author: StanFromIreland

Doc/library/unicodedata.rst

@@ -146,8 +146,9 @@ following functions:
 
 .. function:: isidstart(chr, /)
 
-   Return ``True`` if the character has the ``XID_Start`` property, ``False``
-   otherwise. For example::
+   Return ``True`` if *chr* is a valid identifier start per the
+   `Unicode Standard Annex #31 <https://www.unicode.org/reports/tr31/>`_,
+   that is, it has the ``XID_Start`` property, ``False`` otherwise. For example::
 
       >>> unicodedata.isidstart('S')
       True
@@ -159,8 +160,9 @@ following functions:
 
 .. function:: isidcontinue(chr, /)
 
-   Return ``True`` if the character has the ``XID_Continue`` property, ``False``
-   otherwise. For example::
+   Return ``True`` if *chr* is a valid identifier charcter per the
+   `Unicode Standard Annex #31 <https://www.unicode.org/reports/tr31/>`_,
+   that is, it has the ``XID_Continue`` property, ``False`` otherwise. For example::
 
       >>> unicodedata.isidcontinue('S')
       True

Modules/unicodedata.c

@@ -1541,17 +1541,15 @@ static PyObject *
 unicodedata_UCD_isidstart_impl(PyObject *self, int chr)
 /*[clinic end generated code: output=29fbeaf6491d9f85 input=b71b6b1b2db3c16d]*/
 {
-    Py_UCS4 c = (Py_UCS4)chr;
-
     if (UCD_Check(self)) {
-        const change_record *old = get_old_record(self, c);
+        const change_record *old = get_old_record(self, chr);
         if (old->category_changed == 0) {
             /* unassigned */
             Py_RETURN_FALSE;
         }
     }
 
-    return PyBool_FromLong(_PyUnicode_IsXidStart(c));
+    return PyBool_FromLong(_PyUnicode_IsXidStart(chr));
 }
 
 /*[clinic input]
@@ -1569,17 +1567,15 @@ static PyObject *
 unicodedata_UCD_isidcontinue_impl(PyObject *self, int chr)
 /*[clinic end generated code: output=5ae694da0ee16534 input=01b4ccd399484e6b]*/
 {
-    Py_UCS4 c = (Py_UCS4)chr;
-
     if (UCD_Check(self)) {
-        const change_record *old = get_old_record(self, c);
+        const change_record *old = get_old_record(self, chr);
         if (old->category_changed == 0) {
             /* unassigned */
             Py_RETURN_FALSE;
         }
     }
 
-    return PyBool_FromLong(_PyUnicode_IsXidContinue(c));
+    return PyBool_FromLong(_PyUnicode_IsXidContinue(chr));
 }
 
 /*[clinic input]

Objects/unicodectype.c

@@ -9,7 +9,7 @@
 */
 
 #include "Python.h"
-#include "pycore_unicodedata.h"   // _PyUnicode_IsXidStart, _PyUnicode_IsXidContinue
+#include "pycore_unicodedata.h"   // export _PyUnicode_IsXidStart(), _PyUnicode_IsXidContinue()
 
 #define ALPHA_MASK 0x01
 #define DECIMAL_MASK 0x02