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<!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Source to the Rust file `/home/travis/.cargo/registry/src/github.com-1ecc6299db9ec823/utf8-ranges-1.0.0/src/lib.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>lib.rs.html -- source</title><link rel="stylesheet" type="text/css" href="../../normalize.css"><link rel="stylesheet" type="text/css" href="../../rustdoc.css" id="mainThemeStyle"><link rel="stylesheet" type="text/css" href="../../dark.css"><link rel="stylesheet" type="text/css" href="../../light.css" id="themeStyle"><script src="../../storage.js"></script></head><body class="rustdoc source"><!--[if lte IE 8]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"><div class="sidebar-menu">☰</div></nav><div class="theme-picker"><button id="theme-picker" aria-label="Pick another theme!"><img src="../../brush.svg" width="18" alt="Pick another theme!"></button><div id="theme-choices"></div></div><script src="../../theme.js"></script><nav class="sub"><form class="search-form js-only"><div class="search-container"><input class="search-input" name="search" autocomplete="off" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"><a id="settings-menu" href="../../settings.html"><img src="../../wheel.svg" width="18" alt="Change settings"></a></div></form></nav><section id="main" class="content"><pre class="line-numbers"><span id="1"> 1</span>
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<span id="426">426</span>
|
||
<span id="427">427</span>
|
||
<span id="428">428</span>
|
||
<span id="429">429</span>
|
||
<span id="430">430</span>
|
||
<span id="431">431</span>
|
||
<span id="432">432</span>
|
||
<span id="433">433</span>
|
||
<span id="434">434</span>
|
||
<span id="435">435</span>
|
||
<span id="436">436</span>
|
||
<span id="437">437</span>
|
||
<span id="438">438</span>
|
||
<span id="439">439</span>
|
||
<span id="440">440</span>
|
||
<span id="441">441</span>
|
||
<span id="442">442</span>
|
||
<span id="443">443</span>
|
||
<span id="444">444</span>
|
||
<span id="445">445</span>
|
||
<span id="446">446</span>
|
||
<span id="447">447</span>
|
||
<span id="448">448</span>
|
||
<span id="449">449</span>
|
||
<span id="450">450</span>
|
||
<span id="451">451</span>
|
||
<span id="452">452</span>
|
||
<span id="453">453</span>
|
||
<span id="454">454</span>
|
||
<span id="455">455</span>
|
||
<span id="456">456</span>
|
||
<span id="457">457</span>
|
||
<span id="458">458</span>
|
||
<span id="459">459</span>
|
||
<span id="460">460</span>
|
||
<span id="461">461</span>
|
||
<span id="462">462</span>
|
||
<span id="463">463</span>
|
||
<span id="464">464</span>
|
||
<span id="465">465</span>
|
||
<span id="466">466</span>
|
||
<span id="467">467</span>
|
||
<span id="468">468</span>
|
||
<span id="469">469</span>
|
||
<span id="470">470</span>
|
||
<span id="471">471</span>
|
||
<span id="472">472</span>
|
||
<span id="473">473</span>
|
||
<span id="474">474</span>
|
||
<span id="475">475</span>
|
||
<span id="476">476</span>
|
||
<span id="477">477</span>
|
||
<span id="478">478</span>
|
||
<span id="479">479</span>
|
||
<span id="480">480</span>
|
||
<span id="481">481</span>
|
||
<span id="482">482</span>
|
||
<span id="483">483</span>
|
||
<span id="484">484</span>
|
||
<span id="485">485</span>
|
||
<span id="486">486</span>
|
||
<span id="487">487</span>
|
||
<span id="488">488</span>
|
||
<span id="489">489</span>
|
||
<span id="490">490</span>
|
||
<span id="491">491</span>
|
||
<span id="492">492</span>
|
||
<span id="493">493</span>
|
||
<span id="494">494</span>
|
||
<span id="495">495</span>
|
||
<span id="496">496</span>
|
||
<span id="497">497</span>
|
||
<span id="498">498</span>
|
||
<span id="499">499</span>
|
||
<span id="500">500</span>
|
||
<span id="501">501</span>
|
||
<span id="502">502</span>
|
||
<span id="503">503</span>
|
||
<span id="504">504</span>
|
||
<span id="505">505</span>
|
||
<span id="506">506</span>
|
||
<span id="507">507</span>
|
||
<span id="508">508</span>
|
||
<span id="509">509</span>
|
||
<span id="510">510</span>
|
||
<span id="511">511</span>
|
||
<span id="512">512</span>
|
||
<span id="513">513</span>
|
||
<span id="514">514</span>
|
||
<span id="515">515</span>
|
||
<span id="516">516</span>
|
||
<span id="517">517</span>
|
||
<span id="518">518</span>
|
||
<span id="519">519</span>
|
||
<span id="520">520</span>
|
||
<span id="521">521</span>
|
||
<span id="522">522</span>
|
||
<span id="523">523</span>
|
||
<span id="524">524</span>
|
||
<span id="525">525</span>
|
||
<span id="526">526</span>
|
||
<span id="527">527</span>
|
||
</pre><pre class="rust ">
|
||
<span class="doccomment">/*!
|
||
Crate `utf8-ranges` converts ranges of Unicode scalar values to equivalent
|
||
ranges of UTF-8 bytes. This is useful for constructing byte based automatons
|
||
that need to embed UTF-8 decoding.
|
||
|
||
See the documentation on the `Utf8Sequences` iterator for more details and
|
||
an example.
|
||
|
||
# Wait, what is this?
|
||
|
||
This is simplest to explain with an example. Let's say you wanted to test
|
||
whether a particular byte sequence was a Cyrillic character. One possible
|
||
scalar value range is `[0400-04FF]`. The set of allowed bytes for this
|
||
range can be expressed as a sequence of byte ranges:
|
||
|
||
```ignore
|
||
[D0-D3][80-BF]
|
||
```
|
||
|
||
This is simple enough: simply encode the boundaries, `0400` encodes to
|
||
`D0 80` and `04FF` encodes to `D3 BF`, and create ranges from each
|
||
corresponding pair of bytes: `D0` to `D3` and `80` to `BF`.
|
||
|
||
However, what if you wanted to add the Cyrillic Supplementary characters to
|
||
your range? Your range might then become `[0400-052F]`. The same procedure
|
||
as above doesn't quite work because `052F` encodes to `D4 AF`. The byte ranges
|
||
you'd get from the previous transformation would be `[D0-D4][80-AF]`. However,
|
||
this isn't quite correct because this range doesn't capture many characters,
|
||
for example, `04FF` (because its last byte, `BF` isn't in the range `80-AF`).
|
||
|
||
Instead, you need multiple sequences of byte ranges:
|
||
|
||
```ignore
|
||
[D0-D3][80-BF] # matches codepoints 0400-04FF
|
||
[D4][80-AF] # matches codepoints 0500-052F
|
||
```
|
||
|
||
This gets even more complicated if you want bigger ranges, particularly if
|
||
they naively contain surrogate codepoints. For example, the sequence of byte
|
||
ranges for the basic multilingual plane (`[0000-FFFF]`) look like this:
|
||
|
||
```ignore
|
||
[0-7F]
|
||
[C2-DF][80-BF]
|
||
[E0][A0-BF][80-BF]
|
||
[E1-EC][80-BF][80-BF]
|
||
[ED][80-9F][80-BF]
|
||
[EE-EF][80-BF][80-BF]
|
||
```
|
||
|
||
Note that the byte ranges above will *not* match any erroneous encoding of
|
||
UTF-8, including encodings of surrogate codepoints.
|
||
|
||
And, of course, for all of Unicode (`[000000-10FFFF]`):
|
||
|
||
```ignore
|
||
[0-7F]
|
||
[C2-DF][80-BF]
|
||
[E0][A0-BF][80-BF]
|
||
[E1-EC][80-BF][80-BF]
|
||
[ED][80-9F][80-BF]
|
||
[EE-EF][80-BF][80-BF]
|
||
[F0][90-BF][80-BF][80-BF]
|
||
[F1-F3][80-BF][80-BF][80-BF]
|
||
[F4][80-8F][80-BF][80-BF]
|
||
```
|
||
|
||
This crate automates the process of creating these byte ranges from ranges of
|
||
Unicode scalar values.
|
||
|
||
# Why would I ever use this?
|
||
|
||
You probably won't ever need this. In 99% of cases, you just decode the byte
|
||
sequence into a Unicode scalar value and compare scalar values directly.
|
||
However, this explicit decoding step isn't always possible. For example, the
|
||
construction of some finite state machines may benefit from converting ranges
|
||
of scalar values into UTF-8 decoder automata (e.g., for character classes in
|
||
regular expressions).
|
||
|
||
# Lineage
|
||
|
||
I got the idea and general implementation strategy from Russ Cox in his
|
||
[article on regexps](https://web.archive.org/web/20160404141123/https://swtch.com/~rsc/regexp/regexp3.html) and RE2.
|
||
Russ Cox got it from Ken Thompson's `grep` (no source, folk lore?).
|
||
I also got the idea from
|
||
[Lucene](https://github.com/apache/lucene-solr/blob/ae93f4e7ac6a3908046391de35d4f50a0d3c59ca/lucene/core/src/java/org/apache/lucene/util/automaton/UTF32ToUTF8.java),
|
||
which uses it for executing automata on their term index.
|
||
*/</span>
|
||
|
||
<span class="attribute">#![<span class="ident">deny</span>(<span class="ident">missing_docs</span>)]</span>
|
||
|
||
<span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">test</span>)]</span> <span class="kw">extern</span> <span class="kw">crate</span> <span class="ident">quickcheck</span>;
|
||
|
||
<span class="kw">use</span> <span class="ident">std</span>::<span class="ident">char</span>;
|
||
<span class="kw">use</span> <span class="ident">std</span>::<span class="ident">fmt</span>;
|
||
<span class="kw">use</span> <span class="ident">std</span>::<span class="ident">slice</span>;
|
||
|
||
<span class="kw">use</span> <span class="ident">char_utf8</span>::<span class="ident">encode_utf8</span>;
|
||
|
||
<span class="kw">const</span> <span class="ident">MAX_UTF8_BYTES</span>: <span class="ident">usize</span> <span class="op">=</span> <span class="number">4</span>;
|
||
|
||
<span class="kw">mod</span> <span class="ident">char_utf8</span>;
|
||
|
||
<span class="doccomment">/// Utf8Sequence represents a sequence of byte ranges.</span>
|
||
<span class="doccomment">///</span>
|
||
<span class="doccomment">/// To match a Utf8Sequence, a candidate byte sequence must match each</span>
|
||
<span class="doccomment">/// successive range.</span>
|
||
<span class="doccomment">///</span>
|
||
<span class="doccomment">/// For example, if there are two ranges, `[C2-DF][80-BF]`, then the byte</span>
|
||
<span class="doccomment">/// sequence `\xDD\x61` would not match because `0x61 < 0x80`.</span>
|
||
<span class="attribute">#[<span class="ident">derive</span>(<span class="ident">Copy</span>, <span class="ident">Clone</span>, <span class="ident">Eq</span>, <span class="ident">PartialEq</span>)]</span>
|
||
<span class="kw">pub</span> <span class="kw">enum</span> <span class="ident">Utf8Sequence</span> {
|
||
<span class="doccomment">/// One byte range.</span>
|
||
<span class="ident">One</span>(<span class="ident">Utf8Range</span>),
|
||
<span class="doccomment">/// Two successive byte ranges.</span>
|
||
<span class="ident">Two</span>([<span class="ident">Utf8Range</span>; <span class="number">2</span>]),
|
||
<span class="doccomment">/// Three successive byte ranges.</span>
|
||
<span class="ident">Three</span>([<span class="ident">Utf8Range</span>; <span class="number">3</span>]),
|
||
<span class="doccomment">/// Four successive byte ranges.</span>
|
||
<span class="ident">Four</span>([<span class="ident">Utf8Range</span>; <span class="number">4</span>]),
|
||
}
|
||
|
||
<span class="kw">impl</span> <span class="ident">Utf8Sequence</span> {
|
||
<span class="doccomment">/// Creates a new UTF-8 sequence from the encoded bytes of a scalar value</span>
|
||
<span class="doccomment">/// range.</span>
|
||
<span class="doccomment">///</span>
|
||
<span class="doccomment">/// This assumes that `start` and `end` have the same length.</span>
|
||
<span class="kw">fn</span> <span class="ident">from_encoded_range</span>(<span class="ident">start</span>: <span class="kw-2">&</span>[<span class="ident">u8</span>], <span class="ident">end</span>: <span class="kw-2">&</span>[<span class="ident">u8</span>]) <span class="op">-></span> <span class="self">Self</span> {
|
||
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">start</span>.<span class="ident">len</span>(), <span class="ident">end</span>.<span class="ident">len</span>());
|
||
<span class="kw">match</span> <span class="ident">start</span>.<span class="ident">len</span>() {
|
||
<span class="number">2</span> <span class="op">=></span> <span class="ident">Utf8Sequence</span>::<span class="ident">Two</span>([
|
||
<span class="ident">Utf8Range</span>::<span class="ident">new</span>(<span class="ident">start</span>[<span class="number">0</span>], <span class="ident">end</span>[<span class="number">0</span>]),
|
||
<span class="ident">Utf8Range</span>::<span class="ident">new</span>(<span class="ident">start</span>[<span class="number">1</span>], <span class="ident">end</span>[<span class="number">1</span>]),
|
||
]),
|
||
<span class="number">3</span> <span class="op">=></span> <span class="ident">Utf8Sequence</span>::<span class="ident">Three</span>([
|
||
<span class="ident">Utf8Range</span>::<span class="ident">new</span>(<span class="ident">start</span>[<span class="number">0</span>], <span class="ident">end</span>[<span class="number">0</span>]),
|
||
<span class="ident">Utf8Range</span>::<span class="ident">new</span>(<span class="ident">start</span>[<span class="number">1</span>], <span class="ident">end</span>[<span class="number">1</span>]),
|
||
<span class="ident">Utf8Range</span>::<span class="ident">new</span>(<span class="ident">start</span>[<span class="number">2</span>], <span class="ident">end</span>[<span class="number">2</span>]),
|
||
]),
|
||
<span class="number">4</span> <span class="op">=></span> <span class="ident">Utf8Sequence</span>::<span class="ident">Four</span>([
|
||
<span class="ident">Utf8Range</span>::<span class="ident">new</span>(<span class="ident">start</span>[<span class="number">0</span>], <span class="ident">end</span>[<span class="number">0</span>]),
|
||
<span class="ident">Utf8Range</span>::<span class="ident">new</span>(<span class="ident">start</span>[<span class="number">1</span>], <span class="ident">end</span>[<span class="number">1</span>]),
|
||
<span class="ident">Utf8Range</span>::<span class="ident">new</span>(<span class="ident">start</span>[<span class="number">2</span>], <span class="ident">end</span>[<span class="number">2</span>]),
|
||
<span class="ident">Utf8Range</span>::<span class="ident">new</span>(<span class="ident">start</span>[<span class="number">3</span>], <span class="ident">end</span>[<span class="number">3</span>]),
|
||
]),
|
||
<span class="ident">n</span> <span class="op">=></span> <span class="macro">unreachable</span><span class="macro">!</span>(<span class="string">"invalid encoded length: {}"</span>, <span class="ident">n</span>),
|
||
}
|
||
}
|
||
|
||
<span class="doccomment">/// Returns the underlying sequence of byte ranges as a slice.</span>
|
||
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">as_slice</span>(<span class="kw-2">&</span><span class="self">self</span>) <span class="op">-></span> <span class="kw-2">&</span>[<span class="ident">Utf8Range</span>] {
|
||
<span class="kw">use</span> <span class="self">self</span>::<span class="ident">Utf8Sequence</span>::<span class="kw-2">*</span>;
|
||
<span class="kw">match</span> <span class="kw-2">*</span><span class="self">self</span> {
|
||
<span class="ident">One</span>(<span class="kw-2">ref</span> <span class="ident">r</span>) <span class="op">=></span> <span class="kw">unsafe</span> { <span class="ident">slice</span>::<span class="ident">from_raw_parts</span>(<span class="ident">r</span>, <span class="number">1</span>) },
|
||
<span class="ident">Two</span>(<span class="kw-2">ref</span> <span class="ident">r</span>) <span class="op">=></span> <span class="kw-2">&</span><span class="ident">r</span>[..],
|
||
<span class="ident">Three</span>(<span class="kw-2">ref</span> <span class="ident">r</span>) <span class="op">=></span> <span class="kw-2">&</span><span class="ident">r</span>[..],
|
||
<span class="ident">Four</span>(<span class="kw-2">ref</span> <span class="ident">r</span>) <span class="op">=></span> <span class="kw-2">&</span><span class="ident">r</span>[..],
|
||
}
|
||
}
|
||
|
||
<span class="doccomment">/// Returns the number of byte ranges in this sequence.</span>
|
||
<span class="doccomment">///</span>
|
||
<span class="doccomment">/// The length is guaranteed to be in the closed interval `[1, 4]`.</span>
|
||
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">len</span>(<span class="kw-2">&</span><span class="self">self</span>) <span class="op">-></span> <span class="ident">usize</span> {
|
||
<span class="self">self</span>.<span class="ident">as_slice</span>().<span class="ident">len</span>()
|
||
}
|
||
|
||
<span class="doccomment">/// Returns true if and only if a prefix of `bytes` matches this sequence</span>
|
||
<span class="doccomment">/// of byte ranges.</span>
|
||
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">matches</span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">bytes</span>: <span class="kw-2">&</span>[<span class="ident">u8</span>]) <span class="op">-></span> <span class="ident">bool</span> {
|
||
<span class="kw">if</span> <span class="ident">bytes</span>.<span class="ident">len</span>() <span class="op"><</span> <span class="self">self</span>.<span class="ident">len</span>() {
|
||
<span class="kw">return</span> <span class="bool-val">false</span>;
|
||
}
|
||
<span class="kw">for</span> (<span class="kw-2">&</span><span class="ident">b</span>, <span class="ident">r</span>) <span class="kw">in</span> <span class="ident">bytes</span>.<span class="ident">iter</span>().<span class="ident">zip</span>(<span class="self">self</span>) {
|
||
<span class="kw">if</span> <span class="op">!</span><span class="ident">r</span>.<span class="ident">matches</span>(<span class="ident">b</span>) {
|
||
<span class="kw">return</span> <span class="bool-val">false</span>;
|
||
}
|
||
}
|
||
<span class="bool-val">true</span>
|
||
}
|
||
}
|
||
|
||
<span class="kw">impl</span><span class="op"><</span><span class="lifetime">'a</span><span class="op">></span> <span class="ident">IntoIterator</span> <span class="kw">for</span> <span class="kw-2">&</span><span class="lifetime">'a</span> <span class="ident">Utf8Sequence</span> {
|
||
<span class="kw">type</span> <span class="ident">IntoIter</span> <span class="op">=</span> <span class="ident">slice</span>::<span class="ident">Iter</span><span class="op"><</span><span class="lifetime">'a</span>, <span class="ident">Utf8Range</span><span class="op">></span>;
|
||
<span class="kw">type</span> <span class="ident">Item</span> <span class="op">=</span> <span class="kw-2">&</span><span class="lifetime">'a</span> <span class="ident">Utf8Range</span>;
|
||
|
||
<span class="kw">fn</span> <span class="ident">into_iter</span>(<span class="self">self</span>) <span class="op">-></span> <span class="self">Self</span>::<span class="ident">IntoIter</span> {
|
||
<span class="self">self</span>.<span class="ident">as_slice</span>().<span class="ident">into_iter</span>()
|
||
}
|
||
}
|
||
|
||
<span class="kw">impl</span> <span class="ident">fmt</span>::<span class="ident">Debug</span> <span class="kw">for</span> <span class="ident">Utf8Sequence</span> {
|
||
<span class="kw">fn</span> <span class="ident">fmt</span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">f</span>: <span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">fmt</span>::<span class="ident">Formatter</span>) <span class="op">-></span> <span class="ident">fmt</span>::<span class="prelude-ty">Result</span> {
|
||
<span class="kw">use</span> <span class="self">self</span>::<span class="ident">Utf8Sequence</span>::<span class="kw-2">*</span>;
|
||
<span class="kw">match</span> <span class="kw-2">*</span><span class="self">self</span> {
|
||
<span class="ident">One</span>(<span class="kw-2">ref</span> <span class="ident">r</span>) <span class="op">=></span> <span class="macro">write</span><span class="macro">!</span>(<span class="ident">f</span>, <span class="string">"{:?}"</span>, <span class="ident">r</span>),
|
||
<span class="ident">Two</span>(<span class="kw-2">ref</span> <span class="ident">r</span>) <span class="op">=></span> <span class="macro">write</span><span class="macro">!</span>(<span class="ident">f</span>, <span class="string">"{:?}{:?}"</span>, <span class="ident">r</span>[<span class="number">0</span>], <span class="ident">r</span>[<span class="number">1</span>]),
|
||
<span class="ident">Three</span>(<span class="kw-2">ref</span> <span class="ident">r</span>) <span class="op">=></span> <span class="macro">write</span><span class="macro">!</span>(<span class="ident">f</span>, <span class="string">"{:?}{:?}{:?}"</span>, <span class="ident">r</span>[<span class="number">0</span>], <span class="ident">r</span>[<span class="number">1</span>], <span class="ident">r</span>[<span class="number">2</span>]),
|
||
<span class="ident">Four</span>(<span class="kw-2">ref</span> <span class="ident">r</span>) <span class="op">=></span> <span class="macro">write</span><span class="macro">!</span>(<span class="ident">f</span>, <span class="string">"{:?}{:?}{:?}{:?}"</span>,
|
||
<span class="ident">r</span>[<span class="number">0</span>], <span class="ident">r</span>[<span class="number">1</span>], <span class="ident">r</span>[<span class="number">2</span>], <span class="ident">r</span>[<span class="number">3</span>]),
|
||
}
|
||
}
|
||
}
|
||
|
||
<span class="doccomment">/// A single inclusive range of UTF-8 bytes.</span>
|
||
<span class="attribute">#[<span class="ident">derive</span>(<span class="ident">Clone</span>, <span class="ident">Copy</span>, <span class="ident">PartialEq</span>, <span class="ident">Eq</span>)]</span>
|
||
<span class="kw">pub</span> <span class="kw">struct</span> <span class="ident">Utf8Range</span> {
|
||
<span class="doccomment">/// Start of byte range (inclusive).</span>
|
||
<span class="kw">pub</span> <span class="ident">start</span>: <span class="ident">u8</span>,
|
||
<span class="doccomment">/// End of byte range (inclusive).</span>
|
||
<span class="kw">pub</span> <span class="ident">end</span>: <span class="ident">u8</span>,
|
||
}
|
||
|
||
<span class="kw">impl</span> <span class="ident">Utf8Range</span> {
|
||
<span class="kw">fn</span> <span class="ident">new</span>(<span class="ident">start</span>: <span class="ident">u8</span>, <span class="ident">end</span>: <span class="ident">u8</span>) <span class="op">-></span> <span class="self">Self</span> {
|
||
<span class="ident">Utf8Range</span> { <span class="ident">start</span>: <span class="ident">start</span>, <span class="ident">end</span>: <span class="ident">end</span> }
|
||
}
|
||
|
||
<span class="doccomment">/// Returns true if and only if the given byte is in this range.</span>
|
||
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">matches</span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">b</span>: <span class="ident">u8</span>) <span class="op">-></span> <span class="ident">bool</span> {
|
||
<span class="self">self</span>.<span class="ident">start</span> <span class="op"><=</span> <span class="ident">b</span> <span class="op">&&</span> <span class="ident">b</span> <span class="op"><=</span> <span class="self">self</span>.<span class="ident">end</span>
|
||
}
|
||
}
|
||
|
||
<span class="kw">impl</span> <span class="ident">fmt</span>::<span class="ident">Debug</span> <span class="kw">for</span> <span class="ident">Utf8Range</span> {
|
||
<span class="kw">fn</span> <span class="ident">fmt</span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">f</span>: <span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">fmt</span>::<span class="ident">Formatter</span>) <span class="op">-></span> <span class="ident">fmt</span>::<span class="prelude-ty">Result</span> {
|
||
<span class="kw">if</span> <span class="self">self</span>.<span class="ident">start</span> <span class="op">==</span> <span class="self">self</span>.<span class="ident">end</span> {
|
||
<span class="macro">write</span><span class="macro">!</span>(<span class="ident">f</span>, <span class="string">"[{:X}]"</span>, <span class="self">self</span>.<span class="ident">start</span>)
|
||
} <span class="kw">else</span> {
|
||
<span class="macro">write</span><span class="macro">!</span>(<span class="ident">f</span>, <span class="string">"[{:X}-{:X}]"</span>, <span class="self">self</span>.<span class="ident">start</span>, <span class="self">self</span>.<span class="ident">end</span>)
|
||
}
|
||
}
|
||
}
|
||
|
||
<span class="doccomment">/// An iterator over ranges of matching UTF-8 byte sequences.</span>
|
||
<span class="doccomment">///</span>
|
||
<span class="doccomment">/// The iteration represents an alternation of comprehensive byte sequences</span>
|
||
<span class="doccomment">/// that match precisely the set of UTF-8 encoded scalar values.</span>
|
||
<span class="doccomment">///</span>
|
||
<span class="doccomment">/// A byte sequence corresponds to one of the scalar values in the range given</span>
|
||
<span class="doccomment">/// if and only if it completely matches exactly one of the sequences of byte</span>
|
||
<span class="doccomment">/// ranges produced by this iterator.</span>
|
||
<span class="doccomment">///</span>
|
||
<span class="doccomment">/// Each sequence of byte ranges matches a unique set of bytes. That is, no two</span>
|
||
<span class="doccomment">/// sequences will match the same bytes.</span>
|
||
<span class="doccomment">///</span>
|
||
<span class="doccomment">/// # Example</span>
|
||
<span class="doccomment">///</span>
|
||
<span class="doccomment">/// This shows how to match an arbitrary byte sequence against a range of</span>
|
||
<span class="doccomment">/// scalar values.</span>
|
||
<span class="doccomment">///</span>
|
||
<span class="doccomment">/// ```rust</span>
|
||
<span class="doccomment">/// use utf8_ranges::{Utf8Sequences, Utf8Sequence};</span>
|
||
<span class="doccomment">///</span>
|
||
<span class="doccomment">/// fn matches(seqs: &[Utf8Sequence], bytes: &[u8]) -> bool {</span>
|
||
<span class="doccomment">/// for range in seqs {</span>
|
||
<span class="doccomment">/// if range.matches(bytes) {</span>
|
||
<span class="doccomment">/// return true;</span>
|
||
<span class="doccomment">/// }</span>
|
||
<span class="doccomment">/// }</span>
|
||
<span class="doccomment">/// false</span>
|
||
<span class="doccomment">/// }</span>
|
||
<span class="doccomment">///</span>
|
||
<span class="doccomment">/// // Test the basic multilingual plane.</span>
|
||
<span class="doccomment">/// let seqs: Vec<_> = Utf8Sequences::new('\u{0}', '\u{FFFF}').collect();</span>
|
||
<span class="doccomment">///</span>
|
||
<span class="doccomment">/// // UTF-8 encoding of 'a'.</span>
|
||
<span class="doccomment">/// assert!(matches(&seqs, &[0x61]));</span>
|
||
<span class="doccomment">/// // UTF-8 encoding of '☃' (`\u{2603}`).</span>
|
||
<span class="doccomment">/// assert!(matches(&seqs, &[0xE2, 0x98, 0x83]));</span>
|
||
<span class="doccomment">/// // UTF-8 encoding of `\u{10348}` (outside the BMP).</span>
|
||
<span class="doccomment">/// assert!(!matches(&seqs, &[0xF0, 0x90, 0x8D, 0x88]));</span>
|
||
<span class="doccomment">/// // Tries to match against a UTF-8 encoding of a surrogate codepoint,</span>
|
||
<span class="doccomment">/// // which is invalid UTF-8, and therefore fails, despite the fact that</span>
|
||
<span class="doccomment">/// // the corresponding codepoint (0xD800) falls in the range given.</span>
|
||
<span class="doccomment">/// assert!(!matches(&seqs, &[0xED, 0xA0, 0x80]));</span>
|
||
<span class="doccomment">/// // And fails against plain old invalid UTF-8.</span>
|
||
<span class="doccomment">/// assert!(!matches(&seqs, &[0xFF, 0xFF]));</span>
|
||
<span class="doccomment">/// ```</span>
|
||
<span class="doccomment">///</span>
|
||
<span class="doccomment">/// If this example seems circuitous, that's because it is! It's meant to be</span>
|
||
<span class="doccomment">/// illustrative. In practice, you could just try to decode your byte sequence</span>
|
||
<span class="doccomment">/// and compare it with the scalar value range directly. However, this is not</span>
|
||
<span class="doccomment">/// always possible (for example, in a byte based automaton).</span>
|
||
<span class="kw">pub</span> <span class="kw">struct</span> <span class="ident">Utf8Sequences</span> {
|
||
<span class="ident">range_stack</span>: <span class="ident">Vec</span><span class="op"><</span><span class="ident">ScalarRange</span><span class="op">></span>,
|
||
}
|
||
|
||
<span class="kw">impl</span> <span class="ident">Utf8Sequences</span> {
|
||
<span class="doccomment">/// Create a new iterator over UTF-8 byte ranges for the scalar value range</span>
|
||
<span class="doccomment">/// given.</span>
|
||
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">new</span>(<span class="ident">start</span>: <span class="ident">char</span>, <span class="ident">end</span>: <span class="ident">char</span>) <span class="op">-></span> <span class="self">Self</span> {
|
||
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">it</span> <span class="op">=</span> <span class="ident">Utf8Sequences</span> { <span class="ident">range_stack</span>: <span class="macro">vec</span><span class="macro">!</span>[] };
|
||
<span class="ident">it</span>.<span class="ident">push</span>(<span class="ident">start</span> <span class="kw">as</span> <span class="ident">u32</span>, <span class="ident">end</span> <span class="kw">as</span> <span class="ident">u32</span>);
|
||
<span class="ident">it</span>
|
||
}
|
||
|
||
<span class="doccomment">/// reset resets the scalar value range.</span>
|
||
<span class="doccomment">/// Any existing state is cleared, but resources may be reused.</span>
|
||
<span class="doccomment">///</span>
|
||
<span class="doccomment">/// N.B. Benchmarks say that this method is dubious.</span>
|
||
<span class="attribute">#[<span class="ident">doc</span>(<span class="ident">hidden</span>)]</span>
|
||
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">reset</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="self">self</span>, <span class="ident">start</span>: <span class="ident">char</span>, <span class="ident">end</span>: <span class="ident">char</span>) {
|
||
<span class="self">self</span>.<span class="ident">range_stack</span>.<span class="ident">clear</span>();
|
||
<span class="self">self</span>.<span class="ident">push</span>(<span class="ident">start</span> <span class="kw">as</span> <span class="ident">u32</span>, <span class="ident">end</span> <span class="kw">as</span> <span class="ident">u32</span>);
|
||
}
|
||
|
||
<span class="kw">fn</span> <span class="ident">push</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="self">self</span>, <span class="ident">start</span>: <span class="ident">u32</span>, <span class="ident">end</span>: <span class="ident">u32</span>) {
|
||
<span class="self">self</span>.<span class="ident">range_stack</span>.<span class="ident">push</span>(<span class="ident">ScalarRange</span> { <span class="ident">start</span>: <span class="ident">start</span>, <span class="ident">end</span>: <span class="ident">end</span> });
|
||
}
|
||
}
|
||
|
||
<span class="kw">struct</span> <span class="ident">ScalarRange</span> {
|
||
<span class="ident">start</span>: <span class="ident">u32</span>,
|
||
<span class="ident">end</span>: <span class="ident">u32</span>,
|
||
}
|
||
|
||
<span class="kw">impl</span> <span class="ident">fmt</span>::<span class="ident">Debug</span> <span class="kw">for</span> <span class="ident">ScalarRange</span> {
|
||
<span class="kw">fn</span> <span class="ident">fmt</span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">f</span>: <span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">fmt</span>::<span class="ident">Formatter</span>) <span class="op">-></span> <span class="ident">fmt</span>::<span class="prelude-ty">Result</span> {
|
||
<span class="macro">write</span><span class="macro">!</span>(<span class="ident">f</span>, <span class="string">"ScalarRange({:X}, {:X})"</span>, <span class="self">self</span>.<span class="ident">start</span>, <span class="self">self</span>.<span class="ident">end</span>)
|
||
}
|
||
}
|
||
|
||
<span class="kw">impl</span> <span class="ident">Iterator</span> <span class="kw">for</span> <span class="ident">Utf8Sequences</span> {
|
||
<span class="kw">type</span> <span class="ident">Item</span> <span class="op">=</span> <span class="ident">Utf8Sequence</span>;
|
||
|
||
<span class="kw">fn</span> <span class="ident">next</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="self">self</span>) <span class="op">-></span> <span class="prelude-ty">Option</span><span class="op"><</span><span class="self">Self</span>::<span class="ident">Item</span><span class="op">></span> {
|
||
<span class="lifetime">'TOP</span>:
|
||
<span class="kw">while</span> <span class="kw">let</span> <span class="prelude-val">Some</span>(<span class="kw-2">mut</span> <span class="ident">r</span>) <span class="op">=</span> <span class="self">self</span>.<span class="ident">range_stack</span>.<span class="ident">pop</span>() {
|
||
<span class="lifetime">'INNER</span>:
|
||
<span class="kw">loop</span> {
|
||
<span class="kw">if</span> <span class="kw">let</span> <span class="prelude-val">Some</span>((<span class="ident">r1</span>, <span class="ident">r2</span>)) <span class="op">=</span> <span class="ident">r</span>.<span class="ident">split</span>() {
|
||
<span class="self">self</span>.<span class="ident">push</span>(<span class="ident">r2</span>.<span class="ident">start</span>, <span class="ident">r2</span>.<span class="ident">end</span>);
|
||
<span class="ident">r</span>.<span class="ident">start</span> <span class="op">=</span> <span class="ident">r1</span>.<span class="ident">start</span>;
|
||
<span class="ident">r</span>.<span class="ident">end</span> <span class="op">=</span> <span class="ident">r1</span>.<span class="ident">end</span>;
|
||
<span class="kw">continue</span> <span class="lifetime">'INNER</span>;
|
||
}
|
||
<span class="kw">if</span> <span class="op">!</span><span class="ident">r</span>.<span class="ident">is_valid</span>() {
|
||
<span class="kw">continue</span> <span class="lifetime">'TOP</span>;
|
||
}
|
||
<span class="kw">for</span> <span class="ident">i</span> <span class="kw">in</span> <span class="number">1</span>..<span class="ident">MAX_UTF8_BYTES</span> {
|
||
<span class="kw">let</span> <span class="ident">max</span> <span class="op">=</span> <span class="ident">max_scalar_value</span>(<span class="ident">i</span>);
|
||
<span class="kw">if</span> <span class="ident">r</span>.<span class="ident">start</span> <span class="op"><=</span> <span class="ident">max</span> <span class="op">&&</span> <span class="ident">max</span> <span class="op"><</span> <span class="ident">r</span>.<span class="ident">end</span> {
|
||
<span class="self">self</span>.<span class="ident">push</span>(<span class="ident">max</span> <span class="op">+</span> <span class="number">1</span>, <span class="ident">r</span>.<span class="ident">end</span>);
|
||
<span class="ident">r</span>.<span class="ident">end</span> <span class="op">=</span> <span class="ident">max</span>;
|
||
<span class="kw">continue</span> <span class="lifetime">'INNER</span>;
|
||
}
|
||
}
|
||
<span class="kw">if</span> <span class="kw">let</span> <span class="prelude-val">Some</span>(<span class="ident">ascii_range</span>) <span class="op">=</span> <span class="ident">r</span>.<span class="ident">as_ascii</span>() {
|
||
<span class="kw">return</span> <span class="prelude-val">Some</span>(<span class="ident">Utf8Sequence</span>::<span class="ident">One</span>(<span class="ident">ascii_range</span>));
|
||
}
|
||
<span class="kw">for</span> <span class="ident">i</span> <span class="kw">in</span> <span class="number">1</span>..<span class="ident">MAX_UTF8_BYTES</span> {
|
||
<span class="kw">let</span> <span class="ident">m</span> <span class="op">=</span> (<span class="number">1</span> <span class="op"><<</span> (<span class="number">6</span> <span class="op">*</span> <span class="ident">i</span>)) <span class="op">-</span> <span class="number">1</span>;
|
||
<span class="kw">if</span> (<span class="ident">r</span>.<span class="ident">start</span> <span class="op">&</span> <span class="op">!</span><span class="ident">m</span>) <span class="op">!=</span> (<span class="ident">r</span>.<span class="ident">end</span> <span class="op">&</span> <span class="op">!</span><span class="ident">m</span>) {
|
||
<span class="kw">if</span> (<span class="ident">r</span>.<span class="ident">start</span> <span class="op">&</span> <span class="ident">m</span>) <span class="op">!=</span> <span class="number">0</span> {
|
||
<span class="self">self</span>.<span class="ident">push</span>((<span class="ident">r</span>.<span class="ident">start</span> <span class="op">|</span> <span class="ident">m</span>) <span class="op">+</span> <span class="number">1</span>, <span class="ident">r</span>.<span class="ident">end</span>);
|
||
<span class="ident">r</span>.<span class="ident">end</span> <span class="op">=</span> <span class="ident">r</span>.<span class="ident">start</span> <span class="op">|</span> <span class="ident">m</span>;
|
||
<span class="kw">continue</span> <span class="lifetime">'INNER</span>;
|
||
}
|
||
<span class="kw">if</span> (<span class="ident">r</span>.<span class="ident">end</span> <span class="op">&</span> <span class="ident">m</span>) <span class="op">!=</span> <span class="ident">m</span> {
|
||
<span class="self">self</span>.<span class="ident">push</span>(<span class="ident">r</span>.<span class="ident">end</span> <span class="op">&</span> <span class="op">!</span><span class="ident">m</span>, <span class="ident">r</span>.<span class="ident">end</span>);
|
||
<span class="ident">r</span>.<span class="ident">end</span> <span class="op">=</span> (<span class="ident">r</span>.<span class="ident">end</span> <span class="op">&</span> <span class="op">!</span><span class="ident">m</span>) <span class="op">-</span> <span class="number">1</span>;
|
||
<span class="kw">continue</span> <span class="lifetime">'INNER</span>;
|
||
}
|
||
}
|
||
}
|
||
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">start</span> <span class="op">=</span> [<span class="number">0</span>; <span class="ident">MAX_UTF8_BYTES</span>];
|
||
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">end</span> <span class="op">=</span> [<span class="number">0</span>; <span class="ident">MAX_UTF8_BYTES</span>];
|
||
<span class="kw">let</span> <span class="ident">n</span> <span class="op">=</span> <span class="ident">r</span>.<span class="ident">encode</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">start</span>, <span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">end</span>);
|
||
<span class="kw">return</span> <span class="prelude-val">Some</span>(<span class="ident">Utf8Sequence</span>::<span class="ident">from_encoded_range</span>(
|
||
<span class="kw-2">&</span><span class="ident">start</span>[<span class="number">0</span>..<span class="ident">n</span>], <span class="kw-2">&</span><span class="ident">end</span>[<span class="number">0</span>..<span class="ident">n</span>]));
|
||
}
|
||
}
|
||
<span class="prelude-val">None</span>
|
||
}
|
||
}
|
||
|
||
<span class="kw">impl</span> <span class="ident">ScalarRange</span> {
|
||
<span class="doccomment">/// split splits this range if it overlaps with a surrogate codepoint.</span>
|
||
<span class="doccomment">///</span>
|
||
<span class="doccomment">/// Either or both ranges may be invalid.</span>
|
||
<span class="kw">fn</span> <span class="ident">split</span>(<span class="kw-2">&</span><span class="self">self</span>) <span class="op">-></span> <span class="prelude-ty">Option</span><span class="op"><</span>(<span class="ident">ScalarRange</span>, <span class="ident">ScalarRange</span>)<span class="op">></span> {
|
||
<span class="kw">if</span> <span class="self">self</span>.<span class="ident">start</span> <span class="op"><</span> <span class="number">0xE000</span> <span class="op">&&</span> <span class="self">self</span>.<span class="ident">end</span> <span class="op">></span> <span class="number">0xD7FF</span> {
|
||
<span class="prelude-val">Some</span>((<span class="ident">ScalarRange</span> {
|
||
<span class="ident">start</span>: <span class="self">self</span>.<span class="ident">start</span>,
|
||
<span class="ident">end</span>: <span class="number">0xD7FF</span>,
|
||
}, <span class="ident">ScalarRange</span> {
|
||
<span class="ident">start</span>: <span class="number">0xE000</span>,
|
||
<span class="ident">end</span>: <span class="self">self</span>.<span class="ident">end</span>,
|
||
}))
|
||
} <span class="kw">else</span> {
|
||
<span class="prelude-val">None</span>
|
||
}
|
||
}
|
||
|
||
<span class="doccomment">/// is_valid returns true if and only if start <= end.</span>
|
||
<span class="kw">fn</span> <span class="ident">is_valid</span>(<span class="kw-2">&</span><span class="self">self</span>) <span class="op">-></span> <span class="ident">bool</span> {
|
||
<span class="self">self</span>.<span class="ident">start</span> <span class="op"><=</span> <span class="self">self</span>.<span class="ident">end</span>
|
||
}
|
||
|
||
<span class="doccomment">/// as_ascii returns this range as a Utf8Range if and only if all scalar</span>
|
||
<span class="doccomment">/// values in this range can be encoded as a single byte.</span>
|
||
<span class="kw">fn</span> <span class="ident">as_ascii</span>(<span class="kw-2">&</span><span class="self">self</span>) <span class="op">-></span> <span class="prelude-ty">Option</span><span class="op"><</span><span class="ident">Utf8Range</span><span class="op">></span> {
|
||
<span class="kw">if</span> <span class="self">self</span>.<span class="ident">is_ascii</span>() {
|
||
<span class="prelude-val">Some</span>(<span class="ident">Utf8Range</span>::<span class="ident">new</span>(<span class="self">self</span>.<span class="ident">start</span> <span class="kw">as</span> <span class="ident">u8</span>, <span class="self">self</span>.<span class="ident">end</span> <span class="kw">as</span> <span class="ident">u8</span>))
|
||
} <span class="kw">else</span> {
|
||
<span class="prelude-val">None</span>
|
||
}
|
||
}
|
||
|
||
<span class="doccomment">/// is_ascii returns true if the range is ASCII only (i.e., takes a single</span>
|
||
<span class="doccomment">/// byte to encode any scalar value).</span>
|
||
<span class="kw">fn</span> <span class="ident">is_ascii</span>(<span class="kw-2">&</span><span class="self">self</span>) <span class="op">-></span> <span class="ident">bool</span> {
|
||
<span class="self">self</span>.<span class="ident">is_valid</span>() <span class="op">&&</span> <span class="self">self</span>.<span class="ident">end</span> <span class="op"><=</span> <span class="number">0x7f</span>
|
||
}
|
||
|
||
<span class="doccomment">/// encode writes the UTF-8 encoding of the start and end of this range</span>
|
||
<span class="doccomment">/// to the corresponding destination slices.</span>
|
||
<span class="doccomment">///</span>
|
||
<span class="doccomment">/// The slices should have room for at least `MAX_UTF8_BYTES`.</span>
|
||
<span class="kw">fn</span> <span class="ident">encode</span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">start</span>: <span class="kw-2">&</span><span class="kw-2">mut</span> [<span class="ident">u8</span>], <span class="ident">end</span>: <span class="kw-2">&</span><span class="kw-2">mut</span> [<span class="ident">u8</span>]) <span class="op">-></span> <span class="ident">usize</span> {
|
||
<span class="kw">let</span> <span class="ident">cs</span> <span class="op">=</span> <span class="ident">char</span>::<span class="ident">from_u32</span>(<span class="self">self</span>.<span class="ident">start</span>).<span class="ident">unwrap</span>();
|
||
<span class="kw">let</span> <span class="ident">ce</span> <span class="op">=</span> <span class="ident">char</span>::<span class="ident">from_u32</span>(<span class="self">self</span>.<span class="ident">end</span>).<span class="ident">unwrap</span>();
|
||
<span class="kw">let</span> <span class="ident">n</span> <span class="op">=</span> <span class="ident">encode_utf8</span>(<span class="ident">cs</span>, <span class="ident">start</span>).<span class="ident">unwrap</span>();
|
||
<span class="kw">let</span> <span class="ident">m</span> <span class="op">=</span> <span class="ident">encode_utf8</span>(<span class="ident">ce</span>, <span class="ident">end</span>).<span class="ident">unwrap</span>();
|
||
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">n</span>, <span class="ident">m</span>);
|
||
<span class="ident">n</span>
|
||
}
|
||
}
|
||
|
||
<span class="kw">fn</span> <span class="ident">max_scalar_value</span>(<span class="ident">nbytes</span>: <span class="ident">usize</span>) <span class="op">-></span> <span class="ident">u32</span> {
|
||
<span class="kw">match</span> <span class="ident">nbytes</span> {
|
||
<span class="number">1</span> <span class="op">=></span> <span class="number">0x007F</span>,
|
||
<span class="number">2</span> <span class="op">=></span> <span class="number">0x07FF</span>,
|
||
<span class="number">3</span> <span class="op">=></span> <span class="number">0xFFFF</span>,
|
||
<span class="number">4</span> <span class="op">=></span> <span class="number">0x10FFFF</span>,
|
||
<span class="kw">_</span> <span class="op">=></span> <span class="macro">unreachable</span><span class="macro">!</span>(<span class="string">"invalid UTF-8 byte sequence size"</span>),
|
||
}
|
||
}
|
||
|
||
<span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">test</span>)]</span>
|
||
<span class="kw">mod</span> <span class="ident">tests</span> {
|
||
<span class="kw">use</span> <span class="ident">std</span>::<span class="ident">char</span>;
|
||
|
||
<span class="kw">use</span> <span class="ident">quickcheck</span>::{<span class="ident">TestResult</span>, <span class="ident">quickcheck</span>};
|
||
|
||
<span class="kw">use</span> <span class="ident">char_utf8</span>::<span class="ident">encode_utf8</span>;
|
||
<span class="kw">use</span> {<span class="ident">MAX_UTF8_BYTES</span>, <span class="ident">Utf8Range</span>, <span class="ident">Utf8Sequences</span>};
|
||
|
||
<span class="kw">fn</span> <span class="ident">rutf8</span>(<span class="ident">s</span>: <span class="ident">u8</span>, <span class="ident">e</span>: <span class="ident">u8</span>) <span class="op">-></span> <span class="ident">Utf8Range</span> {
|
||
<span class="ident">Utf8Range</span>::<span class="ident">new</span>(<span class="ident">s</span>, <span class="ident">e</span>)
|
||
}
|
||
|
||
<span class="kw">fn</span> <span class="ident">never_accepts_surrogate_codepoints</span>(<span class="ident">start</span>: <span class="ident">char</span>, <span class="ident">end</span>: <span class="ident">char</span>) {
|
||
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">buf</span> <span class="op">=</span> [<span class="number">0</span>; <span class="ident">MAX_UTF8_BYTES</span>];
|
||
<span class="kw">for</span> <span class="ident">cp</span> <span class="kw">in</span> <span class="number">0xD800</span>..<span class="number">0xE000</span> {
|
||
<span class="kw">let</span> <span class="ident">c</span> <span class="op">=</span> <span class="kw">unsafe</span> { ::<span class="ident">std</span>::<span class="ident">mem</span>::<span class="ident">transmute</span>(<span class="ident">cp</span>) };
|
||
<span class="kw">let</span> <span class="ident">n</span> <span class="op">=</span> <span class="ident">encode_utf8</span>(<span class="ident">c</span>, <span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">buf</span>).<span class="ident">unwrap</span>();
|
||
<span class="kw">for</span> <span class="ident">r</span> <span class="kw">in</span> <span class="ident">Utf8Sequences</span>::<span class="ident">new</span>(<span class="ident">start</span>, <span class="ident">end</span>) {
|
||
<span class="kw">if</span> <span class="ident">r</span>.<span class="ident">matches</span>(<span class="kw-2">&</span><span class="ident">buf</span>[<span class="number">0</span>..<span class="ident">n</span>]) {
|
||
<span class="macro">panic</span><span class="macro">!</span>(<span class="string">"Sequence ({:X}, {:X}) contains range {:?}, \
|
||
which matches surrogate code point {:X} \
|
||
with encoded bytes {:?}"</span>,
|
||
<span class="ident">start</span> <span class="kw">as</span> <span class="ident">u32</span>, <span class="ident">end</span> <span class="kw">as</span> <span class="ident">u32</span>, <span class="ident">r</span>, <span class="ident">cp</span>, <span class="kw-2">&</span><span class="ident">buf</span>[<span class="number">0</span>..<span class="ident">n</span>]);
|
||
}
|
||
}
|
||
}
|
||
}
|
||
|
||
<span class="attribute">#[<span class="ident">test</span>]</span>
|
||
<span class="kw">fn</span> <span class="ident">codepoints_no_surrogates</span>() {
|
||
<span class="ident">never_accepts_surrogate_codepoints</span>(<span class="string">'\u{0}'</span>, <span class="string">'\u{FFFF}'</span>);
|
||
<span class="ident">never_accepts_surrogate_codepoints</span>(<span class="string">'\u{0}'</span>, <span class="string">'\u{10FFFF}'</span>);
|
||
<span class="ident">never_accepts_surrogate_codepoints</span>(<span class="string">'\u{0}'</span>, <span class="string">'\u{10FFFE}'</span>);
|
||
<span class="ident">never_accepts_surrogate_codepoints</span>(<span class="string">'\u{80}'</span>, <span class="string">'\u{10FFFF}'</span>);
|
||
<span class="ident">never_accepts_surrogate_codepoints</span>(<span class="string">'\u{D7FF}'</span>, <span class="string">'\u{E000}'</span>);
|
||
}
|
||
|
||
<span class="attribute">#[<span class="ident">test</span>]</span>
|
||
<span class="kw">fn</span> <span class="ident">single_codepoint_one_sequence</span>() {
|
||
<span class="comment">// Tests that every range of scalar values that contains a single</span>
|
||
<span class="comment">// scalar value is recognized by one sequence of byte ranges.</span>
|
||
<span class="kw">for</span> <span class="ident">i</span> <span class="kw">in</span> <span class="number">0x0</span>..(<span class="number">0x10FFFF</span> <span class="op">+</span> <span class="number">1</span>) {
|
||
<span class="kw">let</span> <span class="ident">c</span> <span class="op">=</span> <span class="kw">match</span> <span class="ident">char</span>::<span class="ident">from_u32</span>(<span class="ident">i</span>) {
|
||
<span class="prelude-val">None</span> <span class="op">=></span> <span class="kw">continue</span>,
|
||
<span class="prelude-val">Some</span>(<span class="ident">c</span>) <span class="op">=></span> <span class="ident">c</span>,
|
||
};
|
||
<span class="kw">let</span> <span class="ident">seqs</span>: <span class="ident">Vec</span><span class="op"><</span><span class="kw">_</span><span class="op">></span> <span class="op">=</span> <span class="ident">Utf8Sequences</span>::<span class="ident">new</span>(<span class="ident">c</span>, <span class="ident">c</span>).<span class="ident">collect</span>();
|
||
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">seqs</span>.<span class="ident">len</span>(), <span class="number">1</span>);
|
||
}
|
||
}
|
||
|
||
<span class="attribute">#[<span class="ident">test</span>]</span>
|
||
<span class="kw">fn</span> <span class="ident">qc_codepoints_no_surrogate</span>() {
|
||
<span class="kw">fn</span> <span class="ident">p</span>(<span class="ident">s</span>: <span class="ident">char</span>, <span class="ident">e</span>: <span class="ident">char</span>) <span class="op">-></span> <span class="ident">TestResult</span> {
|
||
<span class="kw">if</span> <span class="ident">s</span> <span class="op">></span> <span class="ident">e</span> {
|
||
<span class="kw">return</span> <span class="ident">TestResult</span>::<span class="ident">discard</span>();
|
||
}
|
||
<span class="ident">never_accepts_surrogate_codepoints</span>(<span class="ident">s</span>, <span class="ident">e</span>);
|
||
<span class="ident">TestResult</span>::<span class="ident">passed</span>()
|
||
}
|
||
<span class="ident">quickcheck</span>(<span class="ident">p</span> <span class="kw">as</span> <span class="kw">fn</span>(<span class="ident">char</span>, <span class="ident">char</span>) <span class="op">-></span> <span class="ident">TestResult</span>);
|
||
}
|
||
|
||
<span class="attribute">#[<span class="ident">test</span>]</span>
|
||
<span class="kw">fn</span> <span class="ident">bmp</span>() {
|
||
<span class="kw">use</span> <span class="ident">Utf8Sequence</span>::<span class="kw-2">*</span>;
|
||
|
||
<span class="kw">let</span> <span class="ident">seqs</span> <span class="op">=</span> <span class="ident">Utf8Sequences</span>::<span class="ident">new</span>(<span class="string">'\u{0}'</span>, <span class="string">'\u{FFFF}'</span>)
|
||
.<span class="ident">collect</span>::<span class="op"><</span><span class="ident">Vec</span><span class="op"><</span><span class="kw">_</span><span class="op">>></span>();
|
||
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">seqs</span>, <span class="macro">vec</span><span class="macro">!</span>[
|
||
<span class="ident">One</span>(<span class="ident">rutf8</span>(<span class="number">0x0</span>, <span class="number">0x7F</span>)),
|
||
<span class="ident">Two</span>([<span class="ident">rutf8</span>(<span class="number">0xC2</span>, <span class="number">0xDF</span>), <span class="ident">rutf8</span>(<span class="number">0x80</span>, <span class="number">0xBF</span>)]),
|
||
<span class="ident">Three</span>([<span class="ident">rutf8</span>(<span class="number">0xE0</span>, <span class="number">0xE0</span>), <span class="ident">rutf8</span>(<span class="number">0xA0</span>, <span class="number">0xBF</span>), <span class="ident">rutf8</span>(<span class="number">0x80</span>, <span class="number">0xBF</span>)]),
|
||
<span class="ident">Three</span>([<span class="ident">rutf8</span>(<span class="number">0xE1</span>, <span class="number">0xEC</span>), <span class="ident">rutf8</span>(<span class="number">0x80</span>, <span class="number">0xBF</span>), <span class="ident">rutf8</span>(<span class="number">0x80</span>, <span class="number">0xBF</span>)]),
|
||
<span class="ident">Three</span>([<span class="ident">rutf8</span>(<span class="number">0xED</span>, <span class="number">0xED</span>), <span class="ident">rutf8</span>(<span class="number">0x80</span>, <span class="number">0x9F</span>), <span class="ident">rutf8</span>(<span class="number">0x80</span>, <span class="number">0xBF</span>)]),
|
||
<span class="ident">Three</span>([<span class="ident">rutf8</span>(<span class="number">0xEE</span>, <span class="number">0xEF</span>), <span class="ident">rutf8</span>(<span class="number">0x80</span>, <span class="number">0xBF</span>), <span class="ident">rutf8</span>(<span class="number">0x80</span>, <span class="number">0xBF</span>)]),
|
||
]);
|
||
}
|
||
|
||
<span class="attribute">#[<span class="ident">test</span>]</span>
|
||
<span class="kw">fn</span> <span class="ident">scratch</span>() {
|
||
<span class="kw">for</span> <span class="ident">range</span> <span class="kw">in</span> <span class="ident">Utf8Sequences</span>::<span class="ident">new</span>(<span class="string">'\u{0}'</span>, <span class="string">'\u{FFFF}'</span>) {
|
||
<span class="macro">println</span><span class="macro">!</span>(<span class="string">"{:?}"</span>, <span class="ident">range</span>);
|
||
}
|
||
}
|
||
}
|
||
</pre>
|
||
</section><section id="search" class="content hidden"></section><section class="footer"></section><aside id="help" class="hidden"><div><h1 class="hidden">Help</h1><div class="shortcuts"><h2>Keyboard Shortcuts</h2><dl><dt><kbd>?</kbd></dt><dd>Show this help dialog</dd><dt><kbd>S</kbd></dt><dd>Focus the search field</dd><dt><kbd>↑</kbd></dt><dd>Move up in search results</dd><dt><kbd>↓</kbd></dt><dd>Move down in search results</dd><dt><kbd>↹</kbd></dt><dd>Switch tab</dd><dt><kbd>⏎</kbd></dt><dd>Go to active search result</dd><dt><kbd>+</kbd></dt><dd>Expand all sections</dd><dt><kbd>-</kbd></dt><dd>Collapse all sections</dd></dl></div><div class="infos"><h2>Search Tricks</h2><p>Prefix searches with a type followed by a colon (e.g. <code>fn:</code>) to restrict the search to a given type.</p><p>Accepted types are: <code>fn</code>, <code>mod</code>, <code>struct</code>, <code>enum</code>, <code>trait</code>, <code>type</code>, <code>macro</code>, and <code>const</code>.</p><p>Search functions by type signature (e.g. <code>vec -> usize</code> or <code>* -> vec</code>)</p><p>Search multiple things at once by splitting your query with comma (e.g. <code>str,u8</code> or <code>String,struct:Vec,test</code>)</p></div></div></aside><script>window.rootPath = "../../";window.currentCrate = "utf8_ranges";</script><script src="../../aliases.js"></script><script src="../../main.js"></script><script defer src="../../search-index.js"></script></body></html> |