regexmodule.c

python s60 1.4.5版本的源代码

/*
XXX support range parameter on search
XXX support mstop parameter on search
*/


/* Regular expression objects */
/* This uses Tatu Ylonen's copyleft-free reimplementation of
   GNU regular expressions */

#include "Python.h"

#include <ctype.h>

#include "regexpr.h"

static PyObject *RegexError;	/* Exception */	

typedef struct {
	PyObject_HEAD
	struct re_pattern_buffer re_patbuf; /* The compiled expression */
	struct re_registers re_regs; /* The registers from the last match */
	char re_fastmap[256];	/* Storage for fastmap */
	PyObject *re_translate;	/* String object for translate table */
	PyObject *re_lastok;	/* String object last matched/searched */
	PyObject *re_groupindex;	/* Group name to index dictionary */
	PyObject *re_givenpat;	/* Pattern with symbolic groups */
	PyObject *re_realpat;	/* Pattern without symbolic groups */
} regexobject;

/* Regex object methods */

static void
reg_dealloc(regexobject *re)
{
	if (re->re_patbuf.buffer)
		free(re->re_patbuf.buffer);
	Py_XDECREF(re->re_translate);
	Py_XDECREF(re->re_lastok);
	Py_XDECREF(re->re_groupindex);
	Py_XDECREF(re->re_givenpat);
	Py_XDECREF(re->re_realpat);
	PyObject_Del(re);
}

static PyObject *
makeresult(struct re_registers *regs)
{
	PyObject *v;
	int i;
	static PyObject *filler = NULL;

	if (filler == NULL) {
		filler = Py_BuildValue("(ii)", -1, -1);
		if (filler == NULL)
			return NULL;
	}
	v = PyTuple_New(RE_NREGS);
	if (v == NULL)
		return NULL;

	for (i = 0; i < RE_NREGS; i++) {
		int lo = regs->start[i];
		int hi = regs->end[i];
		PyObject *w;
		if (lo == -1 && hi == -1) {
			w = filler;
			Py_INCREF(w);
		}
		else
			w = Py_BuildValue("(ii)", lo, hi);
		if (w == NULL || PyTuple_SetItem(v, i, w) < 0) {
			Py_DECREF(v);
			return NULL;
		}
	}
	return v;
}

static PyObject *
regobj_match(regexobject *re, PyObject *args)
{
	PyObject *argstring;
	char *buffer;
	int size;
	int offset = 0;
	int result;

	if (!PyArg_ParseTuple(args, "O|i:match", &argstring, &offset))
		return NULL;
	if (!PyArg_Parse(argstring, "t#", &buffer, &size))
		return NULL;

	if (offset < 0 || offset > size) {
		PyErr_SetString(RegexError, "match offset out of range");
		return NULL;
	}
	Py_XDECREF(re->re_lastok);
	re->re_lastok = NULL;
	result = _Py_re_match(&re->re_patbuf, (unsigned char *)buffer, size, offset,
			      &re->re_regs);
	if (result < -1) {
		/* Serious failure of some sort; if re_match didn't 
		   set an exception, raise a generic error */
	        if (!PyErr_Occurred())
		        PyErr_SetString(RegexError, "match failure");
		return NULL;
	}
	if (result >= 0) {
		Py_INCREF(argstring);
		re->re_lastok = argstring;
	}
	return PyInt_FromLong((long)result); /* Length of the match or -1 */
}

static PyObject *
regobj_search(regexobject *re, PyObject *args)
{
	PyObject *argstring;
	char *buffer;
	int size;
	int offset = 0;
	int range;
	int result;
	
	if (!PyArg_ParseTuple(args, "O|i:search", &argstring, &offset))
		return NULL;
	if (!PyArg_Parse(argstring, "t#:search", &buffer, &size))
		return NULL;

	if (offset < 0 || offset > size) {
		PyErr_SetString(RegexError, "search offset out of range");
		return NULL;
	}
	/* NB: In Emacs 18.57, the documentation for re_search[_2] and
	   the implementation don't match: the documentation states that
	   |range| positions are tried, while the code tries |range|+1
	   positions.  It seems more productive to believe the code! */
	range = size - offset;
	Py_XDECREF(re->re_lastok);
	re->re_lastok = NULL;
	result = _Py_re_search(&re->re_patbuf, (unsigned char *)buffer, size, offset, range,
			   &re->re_regs);
	if (result < -1) {
		/* Serious failure of some sort; if re_match didn't 
		   set an exception, raise a generic error */
	        if (!PyErr_Occurred())
	  	        PyErr_SetString(RegexError, "match failure");
		return NULL;
	}
	if (result >= 0) {
		Py_INCREF(argstring);
		re->re_lastok = argstring;
	}
	return PyInt_FromLong((long)result); /* Position of the match or -1 */
}

/* get the group from the regex where index can be a string (group name) or
   an integer index [0 .. 99]
 */
static PyObject*
group_from_index(regexobject *re, PyObject *index)
{
	int i, a, b;
	char *v;

	if (PyString_Check(index))
		if (re->re_groupindex == NULL ||
		    !(index = PyDict_GetItem(re->re_groupindex, index)))
		{
			PyErr_SetString(RegexError,
					"group() group name doesn't exist");
			return NULL;
		}

	i = PyInt_AsLong(index);
	if (i == -1 && PyErr_Occurred())
		return NULL;

	if (i < 0 || i >= RE_NREGS) {
		PyErr_SetString(RegexError, "group() index out of range");
		return NULL;
	}
	if (re->re_lastok == NULL) {
		PyErr_SetString(RegexError,
			   "group() only valid after successful match/search");
		return NULL;
	}
	a = re->re_regs.start[i];
	b = re->re_regs.end[i];
	if (a < 0 || b < 0) {
		Py_INCREF(Py_None);
		return Py_None;
	}
	
	if (!(v = PyString_AsString(re->re_lastok)))
		return NULL;

	return PyString_FromStringAndSize(v+a, b-a);
}


static PyObject *
regobj_group(regexobject *re, PyObject *args)
{
	int n = PyTuple_Size(args);
	int i;
	PyObject *res = NULL;

	if (n < 0)
		return NULL;
	if (n == 0) {
		PyErr_SetString(PyExc_TypeError, "not enough arguments");
		return NULL;
	}
	if (n == 1) {
		/* return value is a single string */
		PyObject *index = PyTuple_GetItem(args, 0);
		if (!index)
			return NULL;
		
		return group_from_index(re, index);
	}

	/* return value is a tuple */
	if (!(res = PyTuple_New(n)))
		return NULL;

	for (i = 0; i < n; i++) {
		PyObject *index = PyTuple_GetItem(args, i);
		PyObject *group = NULL;

		if (!index)
			goto finally;
		if (!(group = group_from_index(re, index)))
			goto finally;
		if (PyTuple_SetItem(res, i, group) < 0)
			goto finally;
	}
	return res;

  finally:
	Py_DECREF(res);
	return NULL;
}


static struct PyMethodDef reg_methods[] = {
	{"match",	(PyCFunction)regobj_match, 1},
	{"search",	(PyCFunction)regobj_search, 1},
	{"group",	(PyCFunction)regobj_group, 1},
	{NULL,		NULL}		/* sentinel */
};



static char* members[] = {
	"last", "regs", "translate",
	"groupindex", "realpat", "givenpat",
	NULL
};


static PyObject *
regobj_getattr(regexobject *re, char *name)
{
	if (strcmp(name, "regs") == 0) {
		if (re->re_lastok == NULL) {
			Py_INCREF(Py_None);
			return Py_None;
		}
		return makeresult(&re->re_regs);
	}
	if (strcmp(name, "last") == 0) {
		if (re->re_lastok == NULL) {
			Py_INCREF(Py_None);
			return Py_None;
		}
		Py_INCREF(re->re_lastok);
		return re->re_lastok;
	}
	if (strcmp(name, "translate") == 0) {
		if (re->re_translate == NULL) {
			Py_INCREF(Py_None);
			return Py_None;
		}
		Py_INCREF(re->re_translate);
		return re->re_translate;
	}
	if (strcmp(name, "groupindex") == 0) {
		if (re->re_groupindex == NULL) {
			Py_INCREF(Py_None);
			return Py_None;
		}
		Py_INCREF(re->re_groupindex);
		return re->re_groupindex;
	}
	if (strcmp(name, "realpat") == 0) {
		if (re->re_realpat == NULL) {
			Py_INCREF(Py_None);
			return Py_None;
		}
		Py_INCREF(re->re_realpat);
		return re->re_realpat;
	}
	if (strcmp(name, "givenpat") == 0) {
		if (re->re_givenpat == NULL) {
			Py_INCREF(Py_None);
			return Py_None;
		}
		Py_INCREF(re->re_givenpat);
		return re->re_givenpat;
	}
	if (strcmp(name, "__members__") == 0) {
		int i = 0;
		PyObject *list = NULL;

		/* okay, so it's unlikely this list will change that often.
		   still, it's easier to change it in just one place.
		 */
		while (members[i])
			i++;
		if (!(list = PyList_New(i)))
			return NULL;

		i = 0;
		while (members[i]) {
			PyObject* v = PyString_FromString(members[i]);
			if (!v || PyList_SetItem(list, i, v) < 0) {
				Py_DECREF(list);
				return NULL;
			}
			i++;
		}
		return list;
	}
	return Py_FindMethod(reg_methods, (PyObject *)re, name);
}

static PyTypeObject Regextype = {
	PyObject_HEAD_INIT(NULL)
	0,				     /*ob_size*/
	"regex.regex",			     /*tp_name*/
	sizeof(regexobject),		     /*tp_size*/
	0,				     /*tp_itemsize*/
	/* methods */
	(destructor)reg_dealloc,	     /*tp_dealloc*/
	0,				     /*tp_print*/