| # 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() |
