Roll Observatory packages and add a roll script

quiver/lib/strings.dart

-// Copyright 2013 Google Inc. All Rights Reserved.
-//
-// 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.
-
-library quiver.strings;
-
-/**
- * Returns [true] if [s] is either null, empty or is solely made of whitespace
- * characters (as defined by [String.trim]).
- */
-bool isBlank(String s) => s == null || s.trim().isEmpty;
-
-/**
- * Returns [true] if [s] is either null or empty.
- */
-bool isEmpty(String s) => s == null || s.isEmpty;
-
-/**
- * Returns a string with characters from the given [s] in reverse order.
- */
-String flip(String s) {
-  if (s == null || s == '') return s;
-  StringBuffer sb = new StringBuffer();
-  var runes = s.runes;
-  for (int i = runes.length - 1; i >= 0; i--) {
-    sb.writeCharCode(runes.elementAt(i));
-  }
-  return sb.toString();
-}
-
-/**
- * If [s] is [null] returns empty string, otherwise returns [s] as is.
- */
-String nullToEmpty(String s) => s == null ? '' : s;
-
-/**
- * If [s] is an empty string returns [null], otherwise returns [s] as is.
- */
-String emptyToNull(String s) => s == '' ? null : s;
-
-/**
- * Concatenates [s] to itself a given number of [times]. Empty and null
- * strings will always result in empty and null strings respectively no matter
- * how many [times] they are [repeat]ed.
- *
- * If [times] is negative, returns the [flip]ped string repeated given number
- * of [times].
- */
-String repeat(String s, int times) {
-  if (s == null || s == '') return s;
-  if (times < 0) {
-    return repeat(flip(s), -times);
-  }
-  StringBuffer sink = new StringBuffer();
-  _repeat(sink, s, times);
-  return sink.toString();
-}
-
-/**
- * Loops over [s] and returns traversed characters. Takes arbitrary [from] and
- * [to] indices. Works as a substitute for [String.substring], except it never
- * throws [RangeError]. Supports negative indices. Think of an index as a
- * coordinate in an infinite in both directions vector filled with repeating
- * string [s], whose 0-th coordinate coincides with the 0-th character in [s].
- * Then [loop] returns the sub-vector defined by the interval ([from], [to]).
- * [from] is inclusive. [to] is exclusive.
- *
- * This method throws exceptions on [null] and empty strings.
- *
- * If [to] is omitted or is [null] the traversing ends at the end of the loop.
- *
- * If [to] < [from], traverses [s] in the opposite direction.
- *
- * For example:
- *
- * loop('Hello, World!', 7) == 'World!'
- * loop('ab', 0, 6) == 'ababab'
- * loop('test.txt', -3) == 'txt'
- * loop('ldwor', -3, 2) == 'world'
- */
-String loop(String s, int from, [int to]) {
-  if (s == null || s == '') {
-    throw new ArgumentError('Input string cannot be null or empty');
-  }
-  if (to != null && to < from) {
-    return loop(flip(s), -from, -to);
-  }
-  int len = s.length;
-  int leftFrag = from >= 0 ? from ~/ len : ((from - len) ~/ len);
-  if (to == null) {
-    to = (leftFrag + 1) * len;
-  }
-  int rightFrag = to - 1 >= 0 ? to ~/ len : ((to - len) ~/ len);
-  int fragOffset = rightFrag - leftFrag - 1;
-  if (fragOffset == -1) {
-    return s.substring(from - leftFrag * len, to - rightFrag * len);
-  }
-  StringBuffer sink = new StringBuffer(s.substring(from - leftFrag * len));
-  _repeat(sink, s, fragOffset);
-  sink.write(s.substring(0, to - rightFrag * len));
-  return sink.toString();
-}
-
-void _repeat(StringBuffer sink, String s, int times) {
-  for (int i = 0; i < times; i++) {
-    sink.write(s);
-  }
-}
-
-/**
- * Returns a [String] of length [width] padded on the left with characters from
- * [fill] if `input.length` is less than [width]. [fill] is repeated if
- * neccessary to pad.
- *
- * Returns [input] if `input.length` is equal to or greater than width. [input]
- * can be `null` and is treated as an empty string.
- */
-@Deprecated('Will be removed in 0.22.0')
-String padLeft(String input, int width, String fill) {
-  if (fill == null || fill.length == 0) {
-    throw new ArgumentError('fill cannot be null or empty');
-  }
-  if (input == null || input.length == 0) return loop(fill, 0, width);
-  if (input.length >= width) return input;
-  return loop(fill, 0, width - input.length) + input;
-}
-
-/**
- * Returns a [String] of length [width] padded on the right with characters from
- * [fill] if `input.length` is less than [width]. Characters are selected from
- * [fill] starting at the end, so that the last character in [fill] is the last
- * character in the result. [fill] is repeated if neccessary to pad.
- *
- * Returns [input] if `input.length` is equal to or greater than width. [input]
- * can be `null` and is treated as an empty string.
- */
-@Deprecated('Will be removed in 0.22.0')
-String padRight(String input, int width, String fill) {
-  if (fill == null || fill.length == 0) {
-    throw new ArgumentError('fill cannot be null or empty');
-  }
-  if (input == null || input.length == 0) {
-    return loop(fill, -width, 0);
-  }
-  if (input.length >= width) return input;
-  return input + loop(fill, input.length - width, 0);
-}
-
-/**
- * Removes leading whitespace from a string.
- *
- * Whitespace is defined to be the same as [String.trim].
- */
-@Deprecated('Will be removed in 0.22.0')
-String trimLeft(String input) {
-  int i = 0;
-  for (var rune in input.runes) {
-    if (isWhitespace(rune)) {
-      i++;
-    } else {
-      break;
-    }
-  }
-  return input.substring(i);
-}
-
-/**
- * Removes trailing whitespace from a string.
- *
- * Whitespace is defined to be the same as [String.trim].
- */
-@Deprecated('Will be removed in 0.22.0')
-String trimRight(String input) {
-  int i = 0;
-  int lastNonWhitespace = -1;
-  for (var rune in input.runes) {
-    i++;
-    if (!isWhitespace(rune)) {
-      lastNonWhitespace = i;
-    }
-  }
-  if (lastNonWhitespace == -1) return '';
-  return input.substring(0, lastNonWhitespace);
-}
-
-/**
- * Returns `true` if [rune] represents a whitespace character.
- *
- * The definition of whitespace matches that used in [String.trim] which is
- * based on Unicode 6.2. This maybe be a different set of characters than the
- * environment's [RegExp] definition for whitespace, which is given by the
- * ECMAScript standard: http://ecma-international.org/ecma-262/5.1/#sec-15.10
- */
-bool isWhitespace(int rune) => ((rune >= 0x0009 && rune <= 0x000D) ||
-    rune == 0x0020 ||
-    rune == 0x0085 ||
-    rune == 0x00A0 ||
-    rune == 0x1680 ||
-    rune == 0x180E ||
-    (rune >= 0x2000 && rune <= 0x200A) ||
-    rune == 0x2028 ||
-    rune == 0x2029 ||
-    rune == 0x202F ||
-    rune == 0x205F ||
-    rune == 0x3000 ||
-    rune == 0xFEFF);
-
-/**
- * Returns a [String] of length [width] padded with the same number of
- * characters on the left and right from [fill].  On the right, characters are
- * selected from [fill] starting at the end so that the last character in [fill]
- * is the last character in the result. [fill] is repeated if neccessary to pad.
- *
- * Returns [input] if `input.length` is equal to or greater than width. [input]
- * can be `null` and is treated as an empty string.
- *
- * If there are an odd number of characters to pad, then the right will be
- * padded with one more than the left.
- */
-String center(String input, int width, String fill) {
-  if (fill == null || fill.length == 0) {
-    throw new ArgumentError('fill cannot be null or empty');
-  }
-  if (input == null) input = '';
-  var leftWidth = input.length + (width - input.length) ~/ 2;
-  return padRight(padLeft(input, leftWidth, fill), width, fill);
-}
-
-/**
- * Returns `true` if [a] and [b] are equal after being converted to lower case,
- * or are both null.
- */
-bool equalsIgnoreCase(String a, String b) => (a == null && b == null) ||
-    (a != null && b != null && a.toLowerCase() == b.toLowerCase());
-
-/**
- * Compares [a] and [b] after converting to lower case.
- *
- * Both [a] and [b] must not be null.
- */
-int compareIgnoreCase(String a, String b) =>
-    a.toLowerCase().compareTo(b.toLowerCase());