# Copyright (C) 2014 The Android Open Source Project
|
#
|
# Licensed under the Apache License, Version 2.0 (the "License");
|
# you may not use this file except in compliance with the License.
|
# You may obtain a copy of the License at
|
#
|
# http://www.apache.org/licenses/LICENSE-2.0
|
#
|
# Unless required by applicable law or agreed to in writing, software
|
# distributed under the License is distributed on an "AS IS" BASIS,
|
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
# See the License for the specific language governing permissions and
|
# limitations under the License.
|
|
from __future__ import print_function
|
|
import heapq
|
import itertools
|
|
|
__all__ = ["RangeSet"]
|
|
|
class RangeSet(object):
|
"""A RangeSet represents a set of non-overlapping ranges on integers.
|
|
Attributes:
|
monotonic: Whether the input has all its integers in increasing order.
|
extra: A dict that can be used by the caller, e.g. to store info that's
|
only meaningful to caller.
|
"""
|
|
def __init__(self, data=None):
|
self.monotonic = False
|
self._extra = {}
|
if isinstance(data, str):
|
self._parse_internal(data)
|
elif data:
|
assert len(data) % 2 == 0
|
self.data = tuple(self._remove_pairs(data))
|
self.monotonic = all(x < y for x, y in zip(self.data, self.data[1:]))
|
else:
|
self.data = ()
|
|
def __iter__(self):
|
for i in range(0, len(self.data), 2):
|
yield self.data[i:i+2]
|
|
def __eq__(self, other):
|
return self.data == other.data
|
|
def __ne__(self, other):
|
return self.data != other.data
|
|
def __nonzero__(self):
|
return bool(self.data)
|
|
def __str__(self):
|
if not self.data:
|
return "empty"
|
else:
|
return self.to_string()
|
|
def __repr__(self):
|
return '<RangeSet("' + self.to_string() + '")>'
|
|
@property
|
def extra(self):
|
return self._extra
|
|
@classmethod
|
def parse(cls, text):
|
"""Parses a text string into a RangeSet.
|
|
The input text string consists of a space-separated list of blocks and
|
ranges, e.g. "10-20 30 35-40". Ranges are interpreted to include both their
|
ends (so the above example represents 18 individual blocks). Returns a
|
RangeSet object.
|
|
If the input has all its blocks in increasing order, then the 'monotonic'
|
attribute of the returned RangeSet will be set to True. For example the
|
input "10-20 30" is monotonic, but the input "15-20 30 10-14" is not, even
|
though they represent the same set of blocks (and the two RangeSets will
|
compare equal with ==).
|
"""
|
return cls(text)
|
|
@classmethod
|
def parse_raw(cls, text):
|
"""Parse a string generated by RangeSet.to_string_raw().
|
|
>>> RangeSet.parse_raw(RangeSet("0-9").to_string_raw())
|
<RangeSet("0-9")>
|
"""
|
|
raw = [int(i) for i in text.split(',')]
|
assert raw[0] == len(raw[1:]), "Invalid raw string."
|
|
return cls(data=raw[1:])
|
|
def _parse_internal(self, text):
|
data = []
|
last = -1
|
monotonic = True
|
for p in text.split():
|
if "-" in p:
|
s, e = (int(x) for x in p.split("-"))
|
data.append(s)
|
data.append(e+1)
|
if last <= s <= e:
|
last = e
|
else:
|
monotonic = False
|
else:
|
s = int(p)
|
data.append(s)
|
data.append(s+1)
|
if last <= s:
|
last = s+1
|
else:
|
monotonic = False
|
data.sort()
|
self.data = tuple(self._remove_pairs(data))
|
self.monotonic = monotonic
|
|
@staticmethod
|
def _remove_pairs(source):
|
"""Remove consecutive duplicate items to simplify the result.
|
|
[1, 2, 2, 5, 5, 10] will become [1, 10]."""
|
last = None
|
for i in source:
|
if i == last:
|
last = None
|
else:
|
if last is not None:
|
yield last
|
last = i
|
if last is not None:
|
yield last
|
|
def to_string(self):
|
out = []
|
for i in range(0, len(self.data), 2):
|
s, e = self.data[i:i+2]
|
if e == s+1:
|
out.append(str(s))
|
else:
|
out.append(str(s) + "-" + str(e-1))
|
return " ".join(out)
|
|
def to_string_raw(self):
|
assert self.data
|
return str(len(self.data)) + "," + ",".join(str(i) for i in self.data)
|
|
def union(self, other):
|
"""Return a new RangeSet representing the union of this RangeSet
|
with the argument.
|
|
>>> RangeSet("10-19 30-34").union(RangeSet("18-29"))
|
<RangeSet("10-34")>
|
>>> RangeSet("10-19 30-34").union(RangeSet("22 32"))
|
<RangeSet("10-19 22 30-34")>
|
"""
|
out = []
|
z = 0
|
for p, d in heapq.merge(zip(self.data, itertools.cycle((+1, -1))),
|
zip(other.data, itertools.cycle((+1, -1)))):
|
if (z == 0 and d == 1) or (z == 1 and d == -1):
|
out.append(p)
|
z += d
|
return RangeSet(data=out)
|
|
def intersect(self, other):
|
"""Return a new RangeSet representing the intersection of this
|
RangeSet with the argument.
|
|
>>> RangeSet("10-19 30-34").intersect(RangeSet("18-32"))
|
<RangeSet("18-19 30-32")>
|
>>> RangeSet("10-19 30-34").intersect(RangeSet("22-28"))
|
<RangeSet("")>
|
"""
|
out = []
|
z = 0
|
for p, d in heapq.merge(zip(self.data, itertools.cycle((+1, -1))),
|
zip(other.data, itertools.cycle((+1, -1)))):
|
if (z == 1 and d == 1) or (z == 2 and d == -1):
|
out.append(p)
|
z += d
|
return RangeSet(data=out)
|
|
def subtract(self, other):
|
"""Return a new RangeSet representing subtracting the argument
|
from this RangeSet.
|
|
>>> RangeSet("10-19 30-34").subtract(RangeSet("18-32"))
|
<RangeSet("10-17 33-34")>
|
>>> RangeSet("10-19 30-34").subtract(RangeSet("22-28"))
|
<RangeSet("10-19 30-34")>
|
"""
|
|
out = []
|
z = 0
|
for p, d in heapq.merge(zip(self.data, itertools.cycle((+1, -1))),
|
zip(other.data, itertools.cycle((-1, +1)))):
|
if (z == 0 and d == 1) or (z == 1 and d == -1):
|
out.append(p)
|
z += d
|
return RangeSet(data=out)
|
|
def overlaps(self, other):
|
"""Returns true if the argument has a nonempty overlap with this
|
RangeSet.
|
|
>>> RangeSet("10-19 30-34").overlaps(RangeSet("18-32"))
|
True
|
>>> RangeSet("10-19 30-34").overlaps(RangeSet("22-28"))
|
False
|
"""
|
|
# This is like intersect, but we can stop as soon as we discover the
|
# output is going to be nonempty.
|
z = 0
|
for _, d in heapq.merge(zip(self.data, itertools.cycle((+1, -1))),
|
zip(other.data, itertools.cycle((+1, -1)))):
|
if (z == 1 and d == 1) or (z == 2 and d == -1):
|
return True
|
z += d
|
return False
|
|
def size(self):
|
"""Returns the total size of the RangeSet (ie, how many integers
|
are in the set).
|
|
>>> RangeSet("10-19 30-34").size()
|
15
|
"""
|
|
total = 0
|
for i, p in enumerate(self.data):
|
if i % 2:
|
total += p
|
else:
|
total -= p
|
return total
|
|
def map_within(self, other):
|
"""'other' should be a subset of 'self'. Returns a RangeSet
|
representing what 'other' would get translated to if the integers
|
of 'self' were translated down to be contiguous starting at zero.
|
|
>>> RangeSet("0-9").map_within(RangeSet("3-4"))
|
<RangeSet("3-4")>
|
>>> RangeSet("10-19").map_within(RangeSet("13-14"))
|
<RangeSet("3-4")>
|
>>> RangeSet("10-19 30-39").map_within(RangeSet("17-19 30-32"))
|
<RangeSet("7-12")>
|
>>> RangeSet("10-19 30-39").map_within(RangeSet("12-13 17-19 30-32"))
|
<RangeSet("2-3 7-12")>
|
"""
|
|
out = []
|
offset = 0
|
start = None
|
for p, d in heapq.merge(zip(self.data, itertools.cycle((-5, +5))),
|
zip(other.data, itertools.cycle((-1, +1)))):
|
if d == -5:
|
start = p
|
elif d == +5:
|
offset += p-start
|
start = None
|
else:
|
out.append(offset + p - start)
|
return RangeSet(data=out)
|
|
def extend(self, n):
|
"""Extend the RangeSet by 'n' blocks.
|
|
The lower bound is guaranteed to be non-negative.
|
|
>>> RangeSet("0-9").extend(1)
|
<RangeSet("0-10")>
|
>>> RangeSet("10-19").extend(15)
|
<RangeSet("0-34")>
|
>>> RangeSet("10-19 30-39").extend(4)
|
<RangeSet("6-23 26-43")>
|
>>> RangeSet("10-19 30-39").extend(10)
|
<RangeSet("0-49")>
|
"""
|
out = self
|
for i in range(0, len(self.data), 2):
|
s, e = self.data[i:i+2]
|
s1 = max(0, s - n)
|
e1 = e + n
|
out = out.union(RangeSet(str(s1) + "-" + str(e1-1)))
|
return out
|
|
def first(self, n):
|
"""Return the RangeSet that contains at most the first 'n' integers.
|
|
>>> RangeSet("0-9").first(1)
|
<RangeSet("0")>
|
>>> RangeSet("10-19").first(5)
|
<RangeSet("10-14")>
|
>>> RangeSet("10-19").first(15)
|
<RangeSet("10-19")>
|
>>> RangeSet("10-19 30-39").first(3)
|
<RangeSet("10-12")>
|
>>> RangeSet("10-19 30-39").first(15)
|
<RangeSet("10-19 30-34")>
|
>>> RangeSet("10-19 30-39").first(30)
|
<RangeSet("10-19 30-39")>
|
>>> RangeSet("0-9").first(0)
|
<RangeSet("")>
|
"""
|
|
if self.size() <= n:
|
return self
|
|
out = []
|
for s, e in self:
|
if e - s >= n:
|
out += (s, s+n)
|
break
|
else:
|
out += (s, e)
|
n -= e - s
|
return RangeSet(data=out)
|
|
def next_item(self):
|
"""Return the next integer represented by the RangeSet.
|
|
>>> list(RangeSet("0-9").next_item())
|
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
|
>>> list(RangeSet("10-19 3-5").next_item())
|
[3, 4, 5, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19]
|
>>> list(RangeSet("10-19 3 5 7").next_item())
|
[3, 5, 7, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19]
|
"""
|
for s, e in self:
|
for element in range(s, e):
|
yield element
|
|
|
if __name__ == "__main__":
|
import doctest
|
doctest.testmod()
|
