| # 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 nonoverlapping ranges on the |
| integers (ie, a set of integers, but efficient when the set contains |
| lots of runs.""" |
| |
| def __init__(self, data=None): |
| if isinstance(data, str): |
| self._parse_internal(data) |
| elif data: |
| self.data = tuple(self._remove_pairs(data)) |
| 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() + '")>' |
| |
| @classmethod |
| def parse(cls, text): |
| """Parse a text string consisting of a space-separated list of |
| blocks and ranges, eg "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 returned |
| RangeSet will have an extra attribute 'monotonic' that is 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) |
| |
| def _parse_internal(self, text): |
| data = [] |
| last = -1 |
| monotonic = True |
| for p in text.split(): |
| if "-" in p: |
| s, e = p.split("-") |
| data.append(int(s)) |
| data.append(int(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 = True |
| data.sort() |
| self.data = tuple(self._remove_pairs(data)) |
| self.monotonic = monotonic |
| |
| @staticmethod |
| def _remove_pairs(source): |
| 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): |
| 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 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): |
| 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) |
| |
| |
| if __name__ == "__main__": |
| import doctest |
| doctest.testmod() |