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| -rw-r--r-- | Doc/faq/extending.rst | 156 |
1 files changed, 0 insertions, 156 deletions
diff --git a/Doc/faq/extending.rst b/Doc/faq/extending.rst index aecb56e..1d2aca6 100644 --- a/Doc/faq/extending.rst +++ b/Doc/faq/extending.rst @@ -254,7 +254,6 @@ For Red Hat, install the python-devel RPM to get the necessary files. For Debian, run ``apt-get install python-dev``. - How do I tell "incomplete input" from "invalid input"? ------------------------------------------------------ @@ -273,161 +272,6 @@ you. You can also set the :c:func:`PyOS_ReadlineFunctionPointer` to point at you custom input function. See ``Modules/readline.c`` and ``Parser/myreadline.c`` for more hints. -However sometimes you have to run the embedded Python interpreter in the same -thread as your rest application and you can't allow the -:c:func:`PyRun_InteractiveLoop` to stop while waiting for user input. The one -solution then is to call :c:func:`PyParser_ParseString` and test for ``e.error`` -equal to ``E_EOF``, which means the input is incomplete. Here's a sample code -fragment, untested, inspired by code from Alex Farber:: - - #define PY_SSIZE_T_CLEAN - #include <Python.h> - #include <node.h> - #include <errcode.h> - #include <grammar.h> - #include <parsetok.h> - #include <compile.h> - - int testcomplete(char *code) - /* code should end in \n */ - /* return -1 for error, 0 for incomplete, 1 for complete */ - { - node *n; - perrdetail e; - - n = PyParser_ParseString(code, &_PyParser_Grammar, - Py_file_input, &e); - if (n == NULL) { - if (e.error == E_EOF) - return 0; - return -1; - } - - PyNode_Free(n); - return 1; - } - -Another solution is trying to compile the received string with -:c:func:`Py_CompileString`. If it compiles without errors, try to execute the -returned code object by calling :c:func:`PyEval_EvalCode`. Otherwise save the -input for later. If the compilation fails, find out if it's an error or just -more input is required - by extracting the message string from the exception -tuple and comparing it to the string "unexpected EOF while parsing". Here is a -complete example using the GNU readline library (you may want to ignore -**SIGINT** while calling readline()):: - - #include <stdio.h> - #include <readline.h> - - #define PY_SSIZE_T_CLEAN - #include <Python.h> - #include <object.h> - #include <compile.h> - #include <eval.h> - - int main (int argc, char* argv[]) - { - int i, j, done = 0; /* lengths of line, code */ - char ps1[] = ">>> "; - char ps2[] = "... "; - char *prompt = ps1; - char *msg, *line, *code = NULL; - PyObject *src, *glb, *loc; - PyObject *exc, *val, *trb, *obj, *dum; - - Py_Initialize (); - loc = PyDict_New (); - glb = PyDict_New (); - PyDict_SetItemString (glb, "__builtins__", PyEval_GetBuiltins ()); - - while (!done) - { - line = readline (prompt); - - if (NULL == line) /* Ctrl-D pressed */ - { - done = 1; - } - else - { - i = strlen (line); - - if (i > 0) - add_history (line); /* save non-empty lines */ - - if (NULL == code) /* nothing in code yet */ - j = 0; - else - j = strlen (code); - - code = realloc (code, i + j + 2); - if (NULL == code) /* out of memory */ - exit (1); - - if (0 == j) /* code was empty, so */ - code[0] = '\0'; /* keep strncat happy */ - - strncat (code, line, i); /* append line to code */ - code[i + j] = '\n'; /* append '\n' to code */ - code[i + j + 1] = '\0'; - - src = Py_CompileString (code, "<stdin>", Py_single_input); - - if (NULL != src) /* compiled just fine - */ - { - if (ps1 == prompt || /* ">>> " or */ - '\n' == code[i + j - 1]) /* "... " and double '\n' */ - { /* so execute it */ - dum = PyEval_EvalCode (src, glb, loc); - Py_XDECREF (dum); - Py_XDECREF (src); - free (code); - code = NULL; - if (PyErr_Occurred ()) - PyErr_Print (); - prompt = ps1; - } - } /* syntax error or E_EOF? */ - else if (PyErr_ExceptionMatches (PyExc_SyntaxError)) - { - PyErr_Fetch (&exc, &val, &trb); /* clears exception! */ - - if (PyArg_ParseTuple (val, "sO", &msg, &obj) && - !strcmp (msg, "unexpected EOF while parsing")) /* E_EOF */ - { - Py_XDECREF (exc); - Py_XDECREF (val); - Py_XDECREF (trb); - prompt = ps2; - } - else /* some other syntax error */ - { - PyErr_Restore (exc, val, trb); - PyErr_Print (); - free (code); - code = NULL; - prompt = ps1; - } - } - else /* some non-syntax error */ - { - PyErr_Print (); - free (code); - code = NULL; - prompt = ps1; - } - - free (line); - } - } - - Py_XDECREF(glb); - Py_XDECREF(loc); - Py_Finalize(); - exit(0); - } - - How do I find undefined g++ symbols __builtin_new or __pure_virtual? -------------------------------------------------------------------- |