44 lines
1.2 KiB
Dart
44 lines
1.2 KiB
Dart
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/// Helper functions to performantly transform strings, without `RegExp`.
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library angel3_route.string_util;
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/// Removes leading and trailing occurrences of a pattern from a string.
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String stripStray(String haystack, String needle) {
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int firstSlash;
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if (haystack.startsWith(needle)) {
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firstSlash = haystack.indexOf(needle);
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if (firstSlash == -1) return haystack;
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} else {
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firstSlash = -1;
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}
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if (firstSlash == haystack.length - 1) {
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return haystack.length == 1 ? '' : haystack.substring(0, firstSlash);
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}
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// Find last leading index of slash
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for (var i = firstSlash + 1; i < haystack.length; i++) {
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if (haystack[i] != needle) {
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var sub = haystack.substring(i);
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if (!sub.endsWith(needle)) return sub;
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var lastSlash = sub.lastIndexOf(needle);
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for (var j = lastSlash - 1; j >= 0; j--) {
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if (sub[j] != needle) {
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return sub.substring(0, j + 1);
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}
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}
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return lastSlash == -1 ? sub : sub.substring(0, lastSlash);
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}
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}
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return haystack.substring(0, firstSlash);
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}
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String stripStraySlashes(String str) => stripStray(str, '/');
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String stripRegexStraySlashes(String str) => stripStray(str, '\\/');
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