| <!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 of the Rust file `crates/ide/src/matching_brace.rs`."><title>matching_brace.rs - source</title><script>if(window.location.protocol!=="file:")document.head.insertAdjacentHTML("beforeend","SourceSerif4-Regular-6b053e98.ttf.woff2,FiraSans-Italic-81dc35de.woff2,FiraSans-Regular-0fe48ade.woff2,FiraSans-MediumItalic-ccf7e434.woff2,FiraSans-Medium-e1aa3f0a.woff2,SourceCodePro-Regular-8badfe75.ttf.woff2,SourceCodePro-Semibold-aa29a496.ttf.woff2".split(",").map(f=>`<link rel="preload" as="font" type="font/woff2"href="../../static.files/${f}">`).join(""))</script><link rel="stylesheet" href="../../static.files/normalize-9960930a.css"><link rel="stylesheet" href="../../static.files/rustdoc-77263533.css"><meta name="rustdoc-vars" data-root-path="../../" data-static-root-path="../../static.files/" data-current-crate="ide" data-themes="" data-resource-suffix="" data-rustdoc-version="1.94.0 (4a4ef493e 2026-03-02)" data-channel="1.94.0" data-search-js="search-9e2438ea.js" data-stringdex-js="stringdex-b897f86f.js" data-settings-js="settings-c38705f0.js" ><script src="../../static.files/storage-e2aeef58.js"></script><script defer src="../../static.files/src-script-813739b1.js"></script><script defer src="../../src-files.js"></script><script defer src="../../static.files/main-7bab91a1.js"></script><noscript><link rel="stylesheet" href="../../static.files/noscript-ffcac47a.css"></noscript><link rel="alternate icon" type="image/png" href="../../static.files/favicon-32x32-eab170b8.png"><link rel="icon" type="image/svg+xml" href="../../static.files/favicon-044be391.svg"></head><body class="rustdoc src"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"><div class="src-sidebar-title"><h2>Files</h2></div></nav><div class="sidebar-resizer" title="Drag to resize sidebar"></div><main><section id="main-content" class="content"><div class="main-heading"><h1><div class="sub-heading">ide/</div>matching_brace.rs</h1><rustdoc-toolbar></rustdoc-toolbar></div><div class="example-wrap digits-2"><pre class="rust"><code><a href=#1 id=1 data-nosnippet>1</a><span class="kw">use </span>syntax::{ |
| <a href=#2 id=2 data-nosnippet>2</a> SourceFile, SyntaxKind, T, TextSize, |
| <a href=#3 id=3 data-nosnippet>3</a> ast::{<span class="self">self</span>, AstNode}, |
| <a href=#4 id=4 data-nosnippet>4</a>}; |
| <a href=#5 id=5 data-nosnippet>5</a> |
| <a href=#6 id=6 data-nosnippet>6</a><span class="comment">// Feature: Matching Brace |
| <a href=#7 id=7 data-nosnippet>7</a>// |
| <a href=#8 id=8 data-nosnippet>8</a>// If the cursor is on any brace (`<>(){}[]||`) which is a part of a brace-pair, |
| <a href=#9 id=9 data-nosnippet>9</a>// moves cursor to the matching brace. It uses the actual parser to determine |
| <a href=#10 id=10 data-nosnippet>10</a>// braces, so it won't confuse generics with comparisons. |
| <a href=#11 id=11 data-nosnippet>11</a>// |
| <a href=#12 id=12 data-nosnippet>12</a>// | Editor | Action Name | |
| <a href=#13 id=13 data-nosnippet>13</a>// |---------|-------------| |
| <a href=#14 id=14 data-nosnippet>14</a>// | VS Code | **rust-analyzer: Find matching brace** | |
| <a href=#15 id=15 data-nosnippet>15</a>// |
| <a href=#16 id=16 data-nosnippet>16</a>//  |
| <a href=#17 id=17 data-nosnippet>17</a></span><span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">fn </span>matching_brace(file: <span class="kw-2">&</span>SourceFile, offset: TextSize) -> <span class="prelude-ty">Option</span><TextSize> { |
| <a href=#18 id=18 data-nosnippet>18</a> <span class="kw">const </span>BRACES: <span class="kw-2">&</span>[SyntaxKind] = |
| <a href=#19 id=19 data-nosnippet>19</a> <span class="kw-2">&</span>[<span class="macro">T!</span>[<span class="string">'{'</span>], <span class="macro">T!</span>[<span class="string">'}'</span>], <span class="macro">T!</span>[<span class="string">'['</span>], <span class="macro">T!</span>[<span class="string">']'</span>], <span class="macro">T!</span>[<span class="string">'('</span>], <span class="macro">T!</span>[<span class="string">')'</span>], <span class="macro">T!</span>[<], <span class="macro">T!</span>[>], <span class="macro">T!</span>[|], <span class="macro">T!</span>[|]]; |
| <a href=#20 id=20 data-nosnippet>20</a> <span class="kw">let </span>(brace_token, brace_idx) = file |
| <a href=#21 id=21 data-nosnippet>21</a> .syntax() |
| <a href=#22 id=22 data-nosnippet>22</a> .token_at_offset(offset) |
| <a href=#23 id=23 data-nosnippet>23</a> .filter_map(|node| { |
| <a href=#24 id=24 data-nosnippet>24</a> <span class="kw">let </span>idx = BRACES.iter().position(|<span class="kw-2">&</span>brace| brace == node.kind())<span class="question-mark">?</span>; |
| <a href=#25 id=25 data-nosnippet>25</a> <span class="prelude-val">Some</span>((node, idx)) |
| <a href=#26 id=26 data-nosnippet>26</a> }) |
| <a href=#27 id=27 data-nosnippet>27</a> .last()<span class="question-mark">?</span>; |
| <a href=#28 id=28 data-nosnippet>28</a> <span class="kw">let </span>parent = brace_token.parent()<span class="question-mark">?</span>; |
| <a href=#29 id=29 data-nosnippet>29</a> <span class="kw">if </span>brace_token.kind() == <span class="macro">T!</span>[|] && !ast::ParamList::can_cast(parent.kind()) { |
| <a href=#30 id=30 data-nosnippet>30</a> <span class="macro">cov_mark::hit!</span>(pipes_not_braces); |
| <a href=#31 id=31 data-nosnippet>31</a> <span class="kw">return </span><span class="prelude-val">None</span>; |
| <a href=#32 id=32 data-nosnippet>32</a> } |
| <a href=#33 id=33 data-nosnippet>33</a> <span class="kw">let </span>matching_kind = BRACES[brace_idx ^ <span class="number">1</span>]; |
| <a href=#34 id=34 data-nosnippet>34</a> <span class="kw">let </span>matching_node = parent |
| <a href=#35 id=35 data-nosnippet>35</a> .children_with_tokens() |
| <a href=#36 id=36 data-nosnippet>36</a> .filter_map(|it| it.into_token()) |
| <a href=#37 id=37 data-nosnippet>37</a> .find(|node| node.kind() == matching_kind && <span class="macro">node !</span>= <span class="kw-2">&</span>brace_token)<span class="question-mark">?</span>; |
| <a href=#38 id=38 data-nosnippet>38</a> <span class="prelude-val">Some</span>(matching_node.text_range().start()) |
| <a href=#39 id=39 data-nosnippet>39</a>} |
| <a href=#40 id=40 data-nosnippet>40</a> |
| <a href=#41 id=41 data-nosnippet>41</a><span class="attr">#[cfg(test)] |
| <a href=#42 id=42 data-nosnippet>42</a></span><span class="kw">mod </span>tests { |
| <a href=#43 id=43 data-nosnippet>43</a> <span class="kw">use </span>test_utils::{add_cursor, assert_eq_text, extract_offset}; |
| <a href=#44 id=44 data-nosnippet>44</a> |
| <a href=#45 id=45 data-nosnippet>45</a> <span class="kw">use </span>super::<span class="kw-2">*</span>; |
| <a href=#46 id=46 data-nosnippet>46</a> |
| <a href=#47 id=47 data-nosnippet>47</a> <span class="attr">#[test] |
| <a href=#48 id=48 data-nosnippet>48</a> </span><span class="kw">fn </span>test_matching_brace() { |
| <a href=#49 id=49 data-nosnippet>49</a> <span class="kw">fn </span>do_check(before: <span class="kw-2">&</span>str, after: <span class="kw-2">&</span>str) { |
| <a href=#50 id=50 data-nosnippet>50</a> <span class="kw">let </span>(pos, before) = extract_offset(before); |
| <a href=#51 id=51 data-nosnippet>51</a> <span class="kw">let </span>parse = SourceFile::parse(<span class="kw-2">&</span>before, span::Edition::CURRENT); |
| <a href=#52 id=52 data-nosnippet>52</a> <span class="kw">let </span>new_pos = <span class="kw">match </span>matching_brace(<span class="kw-2">&</span>parse.tree(), pos) { |
| <a href=#53 id=53 data-nosnippet>53</a> <span class="prelude-val">None </span>=> pos, |
| <a href=#54 id=54 data-nosnippet>54</a> <span class="prelude-val">Some</span>(pos) => pos, |
| <a href=#55 id=55 data-nosnippet>55</a> }; |
| <a href=#56 id=56 data-nosnippet>56</a> <span class="kw">let </span>actual = add_cursor(<span class="kw-2">&</span>before, new_pos); |
| <a href=#57 id=57 data-nosnippet>57</a> <span class="macro">assert_eq_text!</span>(after, <span class="kw-2">&</span>actual); |
| <a href=#58 id=58 data-nosnippet>58</a> } |
| <a href=#59 id=59 data-nosnippet>59</a> |
| <a href=#60 id=60 data-nosnippet>60</a> do_check(<span class="string">"struct Foo { a: i32, }$0"</span>, <span class="string">"struct Foo $0{ a: i32, }"</span>); |
| <a href=#61 id=61 data-nosnippet>61</a> do_check(<span class="string">"fn main() { |x: i32|$0 x * 2;}"</span>, <span class="string">"fn main() { $0|x: i32| x * 2;}"</span>); |
| <a href=#62 id=62 data-nosnippet>62</a> do_check(<span class="string">"fn main() { $0|x: i32| x * 2;}"</span>, <span class="string">"fn main() { |x: i32$0| x * 2;}"</span>); |
| <a href=#63 id=63 data-nosnippet>63</a> do_check( |
| <a href=#64 id=64 data-nosnippet>64</a> <span class="string">"fn func(x) { return (2 * (x + 3)$0) + 5;}"</span>, |
| <a href=#65 id=65 data-nosnippet>65</a> <span class="string">"fn func(x) { return $0(2 * (x + 3)) + 5;}"</span>, |
| <a href=#66 id=66 data-nosnippet>66</a> ); |
| <a href=#67 id=67 data-nosnippet>67</a> |
| <a href=#68 id=68 data-nosnippet>68</a> { |
| <a href=#69 id=69 data-nosnippet>69</a> <span class="macro">cov_mark::check!</span>(pipes_not_braces); |
| <a href=#70 id=70 data-nosnippet>70</a> do_check( |
| <a href=#71 id=71 data-nosnippet>71</a> <span class="string">"fn main() { match 92 { 1 | 2 |$0 3 => 92 } }"</span>, |
| <a href=#72 id=72 data-nosnippet>72</a> <span class="string">"fn main() { match 92 { 1 | 2 |$0 3 => 92 } }"</span>, |
| <a href=#73 id=73 data-nosnippet>73</a> ); |
| <a href=#74 id=74 data-nosnippet>74</a> } |
| <a href=#75 id=75 data-nosnippet>75</a> } |
| <a href=#76 id=76 data-nosnippet>76</a>} |
| </code></pre></div></section></main></body></html> |
