Add google-endpoints to third_party/.

third_party/google-endpoints/past/builtins/noniterators.py

+"""
+This module is designed to be used as follows::
+
+    from past.builtins.noniterators import filter, map, range, reduce, zip
+
+And then, for example::
+
+    assert isinstance(range(5), list)
+    
+The list-producing functions this brings in are::
+
+- ``filter``
+- ``map``
+- ``range``
+- ``reduce``
+- ``zip``
+
+"""
+
+from __future__ import division, absolute_import, print_function
+
+from itertools import chain, starmap    
+import itertools       # since zip_longest doesn't exist on Py2
+from past.types import basestring
+from past.utils import PY3
+
+
+def flatmap(f, items):
+    return chain.from_iterable(map(f, items))
+
+
+if PY3:
+    import builtins
+
+    # list-producing versions of the major Python iterating functions
+    def oldfilter(*args):
+        """
+        filter(function or None, sequence) -> list, tuple, or string
+        
+        Return those items of sequence for which function(item) is true.
+        If function is None, return the items that are true.  If sequence
+        is a tuple or string, return the same type, else return a list.
+        """
+        mytype = type(args[1])
+        if isinstance(args[1], basestring):
+            return mytype().join(builtins.filter(*args))
+        elif isinstance(args[1], (tuple, list)):
+            return mytype(builtins.filter(*args))
+        else:
+            # Fall back to list. Is this the right thing to do?
+            return list(builtins.filter(*args))
+
+    # This is surprisingly difficult to get right. For example, the
+    # solutions here fail with the test cases in the docstring below:
+    # http://stackoverflow.com/questions/8072755/
+    def oldmap(func, *iterables):
+        """
+        map(function, sequence[, sequence, ...]) -> list
+        
+        Return a list of the results of applying the function to the
+        items of the argument sequence(s).  If more than one sequence is
+        given, the function is called with an argument list consisting of
+        the corresponding item of each sequence, substituting None for
+        missing values when not all sequences have the same length.  If
+        the function is None, return a list of the items of the sequence
+        (or a list of tuples if more than one sequence).
+        
+        Test cases:
+        >>> oldmap(None, 'hello world')
+        ['h', 'e', 'l', 'l', 'o', ' ', 'w', 'o', 'r', 'l', 'd']
+
+        >>> oldmap(None, range(4))
+        [0, 1, 2, 3]
+
+        More test cases are in past.tests.test_builtins.
+        """
+        zipped = itertools.zip_longest(*iterables)
+        l = list(zipped)
+        if len(l) == 0:
+            return []
+        if func is None:
+            result = l
+        else:
+            result = list(starmap(func, l))
+
+        # Inspect to see whether it's a simple sequence of tuples
+        try:
+            if max([len(item) for item in result]) == 1:
+                return list(chain.from_iterable(result))
+            # return list(flatmap(func, result))
+        except TypeError as e:
+            # Simple objects like ints have no len()
+            pass
+        return result
+
+        ############################
+        ### For reference, the source code for Py2.7 map function:
+        # static PyObject *
+        # builtin_map(PyObject *self, PyObject *args)
+        # {
+        #     typedef struct {
+        #         PyObject *it;           /* the iterator object */
+        #         int saw_StopIteration;  /* bool:  did the iterator end? */
+        #     } sequence;
+        # 
+        #     PyObject *func, *result;
+        #     sequence *seqs = NULL, *sqp;
+        #     Py_ssize_t n, len;
+        #     register int i, j;
+        # 
+        #     n = PyTuple_Size(args);
+        #     if (n < 2) {
+        #         PyErr_SetString(PyExc_TypeError,
+        #                         "map() requires at least two args");
+        #         return NULL;
+        #     }
+        # 
+        #     func = PyTuple_GetItem(args, 0);
+        #     n--;
+        # 
+        #     if (func == Py_None) {
+        #         if (PyErr_WarnPy3k("map(None, ...) not supported in 3.x; "
+        #                            "use list(...)", 1) < 0)
+        #             return NULL;
+        #         if (n == 1) {
+        #             /* map(None, S) is the same as list(S). */
+        #             return PySequence_List(PyTuple_GetItem(args, 1));
+        #         }
+        #     }
+        # 
+        #     /* Get space for sequence descriptors.  Must NULL out the iterator
+        #      * pointers so that jumping to Fail_2 later doesn't see trash.
+        #      */
+        #     if ((seqs = PyMem_NEW(sequence, n)) == NULL) {
+        #         PyErr_NoMemory();
+        #         return NULL;
+        #     }
+        #     for (i = 0; i < n; ++i) {
+        #         seqs[i].it = (PyObject*)NULL;
+        #         seqs[i].saw_StopIteration = 0;
+        #     }
+        # 
+        #     /* Do a first pass to obtain iterators for the arguments, and set len
+        #      * to the largest of their lengths.
+        #      */
+        #     len = 0;
+        #     for (i = 0, sqp = seqs; i < n; ++i, ++sqp) {
+        #         PyObject *curseq;
+        #         Py_ssize_t curlen;
+        # 
+        #         /* Get iterator. */
+        #         curseq = PyTuple_GetItem(args, i+1);
+        #         sqp->it = PyObject_GetIter(curseq);
+        #         if (sqp->it == NULL) {
+        #             static char errmsg[] =
+        #                 "argument %d to map() must support iteration";
+        #             char errbuf[sizeof(errmsg) + 25];
+        #             PyOS_snprintf(errbuf, sizeof(errbuf), errmsg, i+2);
+        #             PyErr_SetString(PyExc_TypeError, errbuf);
+        #             goto Fail_2;
+        #         }
+        # 
+        #         /* Update len. */
+        #         curlen = _PyObject_LengthHint(curseq, 8);
+        #         if (curlen > len)
+        #             len = curlen;
+        #     }
+        # 
+        #     /* Get space for the result list. */
+        #     if ((result = (PyObject *) PyList_New(len)) == NULL)
+        #         goto Fail_2;
+        # 
+        #     /* Iterate over the sequences until all have stopped. */
+        #     for (i = 0; ; ++i) {
+        #         PyObject *alist, *item=NULL, *value;
+        #         int numactive = 0;
+        # 
+        #         if (func == Py_None && n == 1)
+        #             alist = NULL;
+        #         else if ((alist = PyTuple_New(n)) == NULL)
+        #             goto Fail_1;
+        # 
+        #         for (j = 0, sqp = seqs; j < n; ++j, ++sqp) {
+        #             if (sqp->saw_StopIteration) {
+        #                 Py_INCREF(Py_None);
+        #                 item = Py_None;
+        #             }
+        #             else {
+        #                 item = PyIter_Next(sqp->it);
+        #                 if (item)
+        #                     ++numactive;
+        #                 else {
+        #                     if (PyErr_Occurred()) {
+        #                         Py_XDECREF(alist);
+        #                         goto Fail_1;
+        #                     }
+        #                     Py_INCREF(Py_None);
+        #                     item = Py_None;
+        #                     sqp->saw_StopIteration = 1;
+        #                 }
+        #             }
+        #             if (alist)
+        #                 PyTuple_SET_ITEM(alist, j, item);
+        #             else
+        #                 break;
+        #         }
+        # 
+        #         if (!alist)
+        #             alist = item;
+        # 
+        #         if (numactive == 0) {
+        #             Py_DECREF(alist);
+        #             break;
+        #         }
+        # 
+        #         if (func == Py_None)
+        #             value = alist;
+        #         else {
+        #             value = PyEval_CallObject(func, alist);
+        #             Py_DECREF(alist);
+        #             if (value == NULL)
+        #                 goto Fail_1;
+        #         }
+        #         if (i >= len) {
+        #             int status = PyList_Append(result, value);
+        #             Py_DECREF(value);
+        #             if (status < 0)
+        #                 goto Fail_1;
+        #         }
+        #         else if (PyList_SetItem(result, i, value) < 0)
+        #             goto Fail_1;
+        #     }
+        # 
+        #     if (i < len && PyList_SetSlice(result, i, len, NULL) < 0)
+        #         goto Fail_1;
+        # 
+        #     goto Succeed;
+        # 
+        # Fail_1:
+        #     Py_DECREF(result);
+        # Fail_2:
+        #     result = NULL;
+        # Succeed:
+        #     assert(seqs);
+        #     for (i = 0; i < n; ++i)
+        #         Py_XDECREF(seqs[i].it);
+        #     PyMem_DEL(seqs);
+        #     return result;
+        # }
+
+    def oldrange(*args, **kwargs):
+        return list(builtins.range(*args, **kwargs))
+
+    def oldzip(*args, **kwargs):
+        return list(builtins.zip(*args, **kwargs))
+
+    filter = oldfilter
+    map = oldmap
+    range = oldrange
+    from functools import reduce
+    zip = oldzip
+    __all__ = ['filter', 'map', 'range', 'reduce', 'zip']
+
+else:
+    import __builtin__
+    # Python 2-builtin ranges produce lists
+    filter = __builtin__.filter
+    map = __builtin__.map
+    range = __builtin__.range
+    reduce = __builtin__.reduce
+    zip = __builtin__.zip
+    __all__ = []
+