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node_modules/unicode-trie/README.md

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+# unicode-trie
+A data structure for fast Unicode character metadata lookup, ported from ICU
+
+## Background
+
+When implementing many Unicode algorithms such as text segmentation,
+normalization, bidi processing, etc., fast access to character metadata
+is crucial to good performance.  There over a million code points in the
+Unicode standard, many of which produce the same result when looked up,
+so an array or hash table is not appropriate - those data structures are
+fast but would require a lot of memory.  The data is generally
+grouped in ranges, so you could do a binary search, but that is not
+fast enough for some applications.
+
+The [International Components for Unicode](http://site.icu-project.org) (ICU) project
+came up with a data structure based on a [Trie](http://en.wikipedia.org/wiki/Trie) that provides fast access
+to Unicode metadata.  The range data is precompiled to a serialized
+and flattened trie, which is then used at runtime to lookup the necessary
+data.  According to my own tests, this is generally at least 50% faster
+than binary search, with not too much additional memory required.
+
+## Installation
+
+    npm install unicode-trie
+
+## Building a Trie
+
+Unicode Tries are generally precompiled from data in the Unicode database
+for faster runtime performance.  To build a Unicode Trie, use the
+`UnicodeTrieBuilder` class.
+
+```js
+const UnicodeTrieBuilder = require('unicode-trie/builder');
+const fs = require('fs');
+
+// create a trie
+let t = new UnicodeTrieBuilder();
+
+// optional parameters for default value, and error value
+// if not provided, both are set to 0
+t = new UnicodeTrieBuilder(10, 999);
+
+// set individual values and ranges
+t.set(0x4567, 99);
+t.setRange(0x40, 0xe7, 0x1234);
+
+// you can lookup a value if you like
+t.get(0x4567); // => 99
+
+// get a compiled trie (returns a UnicodeTrie object)
+const trie = t.freeze();
+
+// write compressed trie to a binary file
+fs.writeFileSync('data.trie', t.toBuffer());
+```
+
+## Using a precompiled Trie
+
+Once you've built a precompiled trie, you can load it into the
+`UnicodeTrie` class, which is a readonly representation of the
+trie.  From there, you can lookup values.
+
+```js
+const UnicodeTrie = require('unicode-trie');
+const fs = require('fs');
+
+// load serialized trie from binary file
+const data = fs.readFileSync('data.trie');
+const trie = new UnicodeTrie(data);
+
+// lookup a value
+trie.get(0x4567); // => 99
+```
+
+## License
+
+MIT