| 1 | | library dart_style.src.string_compare;
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| 2 | |
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| 3 | | /// Returns `true` if [c] represents a whitespace code unit allowed in Dart
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| 4 | | /// source code.
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| 5 | 12 | bool _isWhitespace(int c) => (c <= 0x000D && c >= 0x0009) || c == 0x0020;
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| 6 | |
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| 7 | | /// Returns the index of the next non-whitespace character.
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| 8 | | ///
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| 9 | | /// Returns `true` if current contains a non-whitespace character.
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| 10 | | /// Returns `false` if no characters are left.
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| 11 | 3 | int _moveNextNonWhitespace(String str, int len, int i) {
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| 12 | 9 | while (i < len && _isWhitespace(str.codeUnitAt(i))) {
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| 13 | 3 | i++;
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| 14 | | }
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| 15 | | return i;
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| 16 | | }
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| 17 | |
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| 18 | | /// Returns `true` if the strings are equal ignoring whitespace characters.
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| 19 | 3 | bool equalIgnoringWhitespace(String str1, String str2) {
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| 20 | | // Benchmarks showed about a 20% regression in formatter performance when
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| 21 | | // when we use the simpler to implement solution of stripping all
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| 22 | | // whitespace characters and checking string equality. This solution is
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| 23 | | // faster due to lower memory usage and poor performance concatting strings
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| 24 | | // together one rune at a time.
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| 25 | |
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| 26 | 3 | var len1 = str1.length;
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| 27 | 3 | var len2 = str2.length;
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| 28 | | var i1 = 0;
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| 29 | | var i2 = 0;
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| 30 | |
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| 31 | | while (true) {
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| 32 | 3 | i1 = _moveNextNonWhitespace(str1, len1, i1);
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| 33 | 3 | i2 = _moveNextNonWhitespace(str2, len2, i2);
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| 34 | 6 | if (i1 >= len1 || i2 >= len2) {
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| 35 | 9 | return (i1 >= len1) == (i2 >= len2);
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| 36 | | }
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| 37 | |
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| 38 | 9 | if (str1[i1] != str2[i2]) return false;
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| 39 | 3 | i1++;
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| 40 | 3 | i2++;
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| 41 | | }
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| 42 | | }
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