| <!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-completion/src/snippet.rs`."><title>snippet.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_completion" 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_completion/</div>snippet.rs</h1><rustdoc-toolbar></rustdoc-toolbar></div><div class="example-wrap digits-3"><pre class="rust"><code><a href=#1 id=1 data-nosnippet>1</a><span class="doccomment">//! User (postfix)-snippet definitions. |
| <a href=#2 id=2 data-nosnippet>2</a>//! |
| <a href=#3 id=3 data-nosnippet>3</a>//! Actual logic is implemented in [`crate::completions::postfix`] and [`crate::completions::snippet`] respectively. |
| <a href=#4 id=4 data-nosnippet>4</a> |
| <a href=#5 id=5 data-nosnippet>5</a></span><span class="comment">// Feature: User Snippet Completions |
| <a href=#6 id=6 data-nosnippet>6</a>// |
| <a href=#7 id=7 data-nosnippet>7</a>// rust-analyzer allows the user to define custom (postfix)-snippets that may depend on items to be accessible for the current scope to be applicable. |
| <a href=#8 id=8 data-nosnippet>8</a>// |
| <a href=#9 id=9 data-nosnippet>9</a>// A custom snippet can be defined by adding it to the `rust-analyzer.completion.snippets.custom` object respectively. |
| <a href=#10 id=10 data-nosnippet>10</a>// |
| <a href=#11 id=11 data-nosnippet>11</a>// ```json |
| <a href=#12 id=12 data-nosnippet>12</a>// { |
| <a href=#13 id=13 data-nosnippet>13</a>// "rust-analyzer.completion.snippets.custom": { |
| <a href=#14 id=14 data-nosnippet>14</a>// "thread spawn": { |
| <a href=#15 id=15 data-nosnippet>15</a>// "prefix": ["spawn", "tspawn"], |
| <a href=#16 id=16 data-nosnippet>16</a>// "body": [ |
| <a href=#17 id=17 data-nosnippet>17</a>// "thread::spawn(move || {", |
| <a href=#18 id=18 data-nosnippet>18</a>// "\t$0", |
| <a href=#19 id=19 data-nosnippet>19</a>// "});", |
| <a href=#20 id=20 data-nosnippet>20</a>// ], |
| <a href=#21 id=21 data-nosnippet>21</a>// "description": "Insert a thread::spawn call", |
| <a href=#22 id=22 data-nosnippet>22</a>// "requires": "std::thread", |
| <a href=#23 id=23 data-nosnippet>23</a>// "scope": "expr", |
| <a href=#24 id=24 data-nosnippet>24</a>// } |
| <a href=#25 id=25 data-nosnippet>25</a>// } |
| <a href=#26 id=26 data-nosnippet>26</a>// } |
| <a href=#27 id=27 data-nosnippet>27</a>// ``` |
| <a href=#28 id=28 data-nosnippet>28</a>// |
| <a href=#29 id=29 data-nosnippet>29</a>// In the example above: |
| <a href=#30 id=30 data-nosnippet>30</a>// |
| <a href=#31 id=31 data-nosnippet>31</a>// * `"thread spawn"` is the name of the snippet. |
| <a href=#32 id=32 data-nosnippet>32</a>// |
| <a href=#33 id=33 data-nosnippet>33</a>// * `prefix` defines one or more trigger words that will trigger the snippets completion. |
| <a href=#34 id=34 data-nosnippet>34</a>// Using `postfix` will instead create a postfix snippet. |
| <a href=#35 id=35 data-nosnippet>35</a>// |
| <a href=#36 id=36 data-nosnippet>36</a>// * `body` is one or more lines of content joined via newlines for the final output. |
| <a href=#37 id=37 data-nosnippet>37</a>// |
| <a href=#38 id=38 data-nosnippet>38</a>// * `description` is an optional description of the snippet, if unset the snippet name will be used. |
| <a href=#39 id=39 data-nosnippet>39</a>// |
| <a href=#40 id=40 data-nosnippet>40</a>// * `requires` is an optional list of item paths that have to be resolvable in the current crate where the completion is rendered. |
| <a href=#41 id=41 data-nosnippet>41</a> |
| <a href=#42 id=42 data-nosnippet>42</a>// On failure of resolution the snippet won't be applicable, otherwise the snippet will insert an import for the items on insertion if |
| <a href=#43 id=43 data-nosnippet>43</a>// the items aren't yet in scope. |
| <a href=#44 id=44 data-nosnippet>44</a>// |
| <a href=#45 id=45 data-nosnippet>45</a>// * `scope` is an optional filter for when the snippet should be applicable. Possible values are: |
| <a href=#46 id=46 data-nosnippet>46</a>// ** for Snippet-Scopes: `expr`, `item` (default: `item`) |
| <a href=#47 id=47 data-nosnippet>47</a>// ** for Postfix-Snippet-Scopes: `expr`, `type` (default: `expr`) |
| <a href=#48 id=48 data-nosnippet>48</a>// |
| <a href=#49 id=49 data-nosnippet>49</a>// The `body` field also has access to placeholders as visible in the example as `$0`. |
| <a href=#50 id=50 data-nosnippet>50</a>// These placeholders take the form of `$number` or `${number:placeholder_text}` which can be traversed as tabstop in ascending order starting from 1, |
| <a href=#51 id=51 data-nosnippet>51</a>// with `$0` being a special case that always comes last. |
| <a href=#52 id=52 data-nosnippet>52</a>// |
| <a href=#53 id=53 data-nosnippet>53</a>// There is also a special placeholder, `${receiver}`, which will be replaced by the receiver expression for postfix snippets, or a `$0` tabstop in case of normal snippets. |
| <a href=#54 id=54 data-nosnippet>54</a>// This replacement for normal snippets allows you to reuse a snippet for both post- and prefix in a single definition. |
| <a href=#55 id=55 data-nosnippet>55</a>// |
| <a href=#56 id=56 data-nosnippet>56</a>// For the VSCode editor, rust-analyzer also ships with a small set of defaults which can be removed |
| <a href=#57 id=57 data-nosnippet>57</a>// by overwriting the settings object mentioned above, the defaults are: |
| <a href=#58 id=58 data-nosnippet>58</a>// |
| <a href=#59 id=59 data-nosnippet>59</a>// ```json |
| <a href=#60 id=60 data-nosnippet>60</a>// { |
| <a href=#61 id=61 data-nosnippet>61</a>// "Arc::new": { |
| <a href=#62 id=62 data-nosnippet>62</a>// "postfix": "arc", |
| <a href=#63 id=63 data-nosnippet>63</a>// "body": "Arc::new(${receiver})", |
| <a href=#64 id=64 data-nosnippet>64</a>// "requires": "std::sync::Arc", |
| <a href=#65 id=65 data-nosnippet>65</a>// "description": "Put the expression into an `Arc`", |
| <a href=#66 id=66 data-nosnippet>66</a>// "scope": "expr" |
| <a href=#67 id=67 data-nosnippet>67</a>// }, |
| <a href=#68 id=68 data-nosnippet>68</a>// "Rc::new": { |
| <a href=#69 id=69 data-nosnippet>69</a>// "postfix": "rc", |
| <a href=#70 id=70 data-nosnippet>70</a>// "body": "Rc::new(${receiver})", |
| <a href=#71 id=71 data-nosnippet>71</a>// "requires": "std::rc::Rc", |
| <a href=#72 id=72 data-nosnippet>72</a>// "description": "Put the expression into an `Rc`", |
| <a href=#73 id=73 data-nosnippet>73</a>// "scope": "expr" |
| <a href=#74 id=74 data-nosnippet>74</a>// }, |
| <a href=#75 id=75 data-nosnippet>75</a>// "Box::pin": { |
| <a href=#76 id=76 data-nosnippet>76</a>// "postfix": "pinbox", |
| <a href=#77 id=77 data-nosnippet>77</a>// "body": "Box::pin(${receiver})", |
| <a href=#78 id=78 data-nosnippet>78</a>// "requires": "std::boxed::Box", |
| <a href=#79 id=79 data-nosnippet>79</a>// "description": "Put the expression into a pinned `Box`", |
| <a href=#80 id=80 data-nosnippet>80</a>// "scope": "expr" |
| <a href=#81 id=81 data-nosnippet>81</a>// }, |
| <a href=#82 id=82 data-nosnippet>82</a>// "Ok": { |
| <a href=#83 id=83 data-nosnippet>83</a>// "postfix": "ok", |
| <a href=#84 id=84 data-nosnippet>84</a>// "body": "Ok(${receiver})", |
| <a href=#85 id=85 data-nosnippet>85</a>// "description": "Wrap the expression in a `Result::Ok`", |
| <a href=#86 id=86 data-nosnippet>86</a>// "scope": "expr" |
| <a href=#87 id=87 data-nosnippet>87</a>// }, |
| <a href=#88 id=88 data-nosnippet>88</a>// "Err": { |
| <a href=#89 id=89 data-nosnippet>89</a>// "postfix": "err", |
| <a href=#90 id=90 data-nosnippet>90</a>// "body": "Err(${receiver})", |
| <a href=#91 id=91 data-nosnippet>91</a>// "description": "Wrap the expression in a `Result::Err`", |
| <a href=#92 id=92 data-nosnippet>92</a>// "scope": "expr" |
| <a href=#93 id=93 data-nosnippet>93</a>// }, |
| <a href=#94 id=94 data-nosnippet>94</a>// "Some": { |
| <a href=#95 id=95 data-nosnippet>95</a>// "postfix": "some", |
| <a href=#96 id=96 data-nosnippet>96</a>// "body": "Some(${receiver})", |
| <a href=#97 id=97 data-nosnippet>97</a>// "description": "Wrap the expression in an `Option::Some`", |
| <a href=#98 id=98 data-nosnippet>98</a>// "scope": "expr" |
| <a href=#99 id=99 data-nosnippet>99</a>// } |
| <a href=#100 id=100 data-nosnippet>100</a>// } |
| <a href=#101 id=101 data-nosnippet>101</a>// ```` |
| <a href=#102 id=102 data-nosnippet>102</a> |
| <a href=#103 id=103 data-nosnippet>103</a></span><span class="kw">use </span>hir::{ModPath, Name, Symbol}; |
| <a href=#104 id=104 data-nosnippet>104</a><span class="kw">use </span>ide_db::imports::import_assets::LocatedImport; |
| <a href=#105 id=105 data-nosnippet>105</a><span class="kw">use </span>itertools::Itertools; |
| <a href=#106 id=106 data-nosnippet>106</a> |
| <a href=#107 id=107 data-nosnippet>107</a><span class="kw">use </span><span class="kw">crate</span>::context::CompletionContext; |
| <a href=#108 id=108 data-nosnippet>108</a> |
| <a href=#109 id=109 data-nosnippet>109</a><span class="doccomment">/// A snippet scope describing where a snippet may apply to. |
| <a href=#110 id=110 data-nosnippet>110</a>/// These may differ slightly in meaning depending on the snippet trigger. |
| <a href=#111 id=111 data-nosnippet>111</a></span><span class="attr">#[derive(Clone, Debug, PartialEq, Eq)] |
| <a href=#112 id=112 data-nosnippet>112</a></span><span class="kw">pub enum </span>SnippetScope { |
| <a href=#113 id=113 data-nosnippet>113</a> Item, |
| <a href=#114 id=114 data-nosnippet>114</a> Expr, |
| <a href=#115 id=115 data-nosnippet>115</a> Type, |
| <a href=#116 id=116 data-nosnippet>116</a>} |
| <a href=#117 id=117 data-nosnippet>117</a> |
| <a href=#118 id=118 data-nosnippet>118</a><span class="doccomment">/// A user supplied snippet. |
| <a href=#119 id=119 data-nosnippet>119</a></span><span class="attr">#[derive(Clone, Debug, PartialEq, Eq)] |
| <a href=#120 id=120 data-nosnippet>120</a></span><span class="kw">pub struct </span>Snippet { |
| <a href=#121 id=121 data-nosnippet>121</a> <span class="kw">pub </span>postfix_triggers: Box<[Box<str>]>, |
| <a href=#122 id=122 data-nosnippet>122</a> <span class="kw">pub </span>prefix_triggers: Box<[Box<str>]>, |
| <a href=#123 id=123 data-nosnippet>123</a> <span class="kw">pub </span>scope: SnippetScope, |
| <a href=#124 id=124 data-nosnippet>124</a> <span class="kw">pub </span>description: <span class="prelude-ty">Option</span><Box<str>>, |
| <a href=#125 id=125 data-nosnippet>125</a> snippet: String, |
| <a href=#126 id=126 data-nosnippet>126</a> requires: Box<[ModPath]>, |
| <a href=#127 id=127 data-nosnippet>127</a>} |
| <a href=#128 id=128 data-nosnippet>128</a> |
| <a href=#129 id=129 data-nosnippet>129</a><span class="kw">impl </span>Snippet { |
| <a href=#130 id=130 data-nosnippet>130</a> <span class="kw">pub fn </span>new( |
| <a href=#131 id=131 data-nosnippet>131</a> prefix_triggers: <span class="kw-2">&</span>[String], |
| <a href=#132 id=132 data-nosnippet>132</a> postfix_triggers: <span class="kw-2">&</span>[String], |
| <a href=#133 id=133 data-nosnippet>133</a> snippet: <span class="kw-2">&</span>[String], |
| <a href=#134 id=134 data-nosnippet>134</a> description: <span class="kw-2">&</span>str, |
| <a href=#135 id=135 data-nosnippet>135</a> requires: <span class="kw-2">&</span>[String], |
| <a href=#136 id=136 data-nosnippet>136</a> scope: SnippetScope, |
| <a href=#137 id=137 data-nosnippet>137</a> ) -> <span class="prelude-ty">Option</span><<span class="self">Self</span>> { |
| <a href=#138 id=138 data-nosnippet>138</a> <span class="kw">if </span>prefix_triggers.is_empty() && postfix_triggers.is_empty() { |
| <a href=#139 id=139 data-nosnippet>139</a> <span class="kw">return </span><span class="prelude-val">None</span>; |
| <a href=#140 id=140 data-nosnippet>140</a> } |
| <a href=#141 id=141 data-nosnippet>141</a> <span class="kw">let </span>(requires, snippet, description) = validate_snippet(snippet, description, requires)<span class="question-mark">?</span>; |
| <a href=#142 id=142 data-nosnippet>142</a> <span class="prelude-val">Some</span>(Snippet { |
| <a href=#143 id=143 data-nosnippet>143</a> postfix_triggers: postfix_triggers.iter().map(String::as_str).map(Into::into).collect(), |
| <a href=#144 id=144 data-nosnippet>144</a> prefix_triggers: prefix_triggers.iter().map(String::as_str).map(Into::into).collect(), |
| <a href=#145 id=145 data-nosnippet>145</a> scope, |
| <a href=#146 id=146 data-nosnippet>146</a> snippet, |
| <a href=#147 id=147 data-nosnippet>147</a> description, |
| <a href=#148 id=148 data-nosnippet>148</a> requires, |
| <a href=#149 id=149 data-nosnippet>149</a> }) |
| <a href=#150 id=150 data-nosnippet>150</a> } |
| <a href=#151 id=151 data-nosnippet>151</a> |
| <a href=#152 id=152 data-nosnippet>152</a> <span class="doccomment">/// Returns [`None`] if the required items do not resolve. |
| <a href=#153 id=153 data-nosnippet>153</a> </span><span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">fn </span>imports(<span class="kw-2">&</span><span class="self">self</span>, ctx: <span class="kw-2">&</span>CompletionContext<<span class="lifetime">'_</span>>) -> <span class="prelude-ty">Option</span><Vec<LocatedImport>> { |
| <a href=#154 id=154 data-nosnippet>154</a> import_edits(ctx, <span class="kw-2">&</span><span class="self">self</span>.requires) |
| <a href=#155 id=155 data-nosnippet>155</a> } |
| <a href=#156 id=156 data-nosnippet>156</a> |
| <a href=#157 id=157 data-nosnippet>157</a> <span class="kw">pub fn </span>snippet(<span class="kw-2">&</span><span class="self">self</span>) -> String { |
| <a href=#158 id=158 data-nosnippet>158</a> <span class="self">self</span>.snippet.replace(<span class="string">"${receiver}"</span>, <span class="string">"$0"</span>) |
| <a href=#159 id=159 data-nosnippet>159</a> } |
| <a href=#160 id=160 data-nosnippet>160</a> |
| <a href=#161 id=161 data-nosnippet>161</a> <span class="kw">pub fn </span>postfix_snippet(<span class="kw-2">&</span><span class="self">self</span>, receiver: <span class="kw-2">&</span>str) -> String { |
| <a href=#162 id=162 data-nosnippet>162</a> <span class="self">self</span>.snippet.replace(<span class="string">"${receiver}"</span>, receiver) |
| <a href=#163 id=163 data-nosnippet>163</a> } |
| <a href=#164 id=164 data-nosnippet>164</a>} |
| <a href=#165 id=165 data-nosnippet>165</a> |
| <a href=#166 id=166 data-nosnippet>166</a><span class="kw">fn </span>import_edits(ctx: <span class="kw-2">&</span>CompletionContext<<span class="lifetime">'_</span>>, requires: <span class="kw-2">&</span>[ModPath]) -> <span class="prelude-ty">Option</span><Vec<LocatedImport>> { |
| <a href=#167 id=167 data-nosnippet>167</a> <span class="kw">let </span>import_cfg = ctx.config.find_path_config(ctx.is_nightly); |
| <a href=#168 id=168 data-nosnippet>168</a> |
| <a href=#169 id=169 data-nosnippet>169</a> <span class="kw">let </span>resolve = |import| { |
| <a href=#170 id=170 data-nosnippet>170</a> <span class="kw">let </span>item = ctx.scope.resolve_mod_path(import).next()<span class="question-mark">?</span>; |
| <a href=#171 id=171 data-nosnippet>171</a> <span class="kw">let </span>path = ctx.module.find_use_path( |
| <a href=#172 id=172 data-nosnippet>172</a> ctx.db, |
| <a href=#173 id=173 data-nosnippet>173</a> item, |
| <a href=#174 id=174 data-nosnippet>174</a> ctx.config.insert_use.prefix_kind, |
| <a href=#175 id=175 data-nosnippet>175</a> import_cfg, |
| <a href=#176 id=176 data-nosnippet>176</a> )<span class="question-mark">?</span>; |
| <a href=#177 id=177 data-nosnippet>177</a> <span class="prelude-val">Some</span>((path.len() > <span class="number">1</span>).then(|| LocatedImport::new_no_completion(path.clone(), item, item))) |
| <a href=#178 id=178 data-nosnippet>178</a> }; |
| <a href=#179 id=179 data-nosnippet>179</a> <span class="kw">let </span><span class="kw-2">mut </span>res = Vec::with_capacity(requires.len()); |
| <a href=#180 id=180 data-nosnippet>180</a> <span class="kw">for </span>import <span class="kw">in </span>requires { |
| <a href=#181 id=181 data-nosnippet>181</a> <span class="kw">match </span>resolve(import) { |
| <a href=#182 id=182 data-nosnippet>182</a> <span class="prelude-val">Some</span>(first) => res.extend(first), |
| <a href=#183 id=183 data-nosnippet>183</a> <span class="prelude-val">None </span>=> <span class="kw">return </span><span class="prelude-val">None</span>, |
| <a href=#184 id=184 data-nosnippet>184</a> } |
| <a href=#185 id=185 data-nosnippet>185</a> } |
| <a href=#186 id=186 data-nosnippet>186</a> <span class="prelude-val">Some</span>(res) |
| <a href=#187 id=187 data-nosnippet>187</a>} |
| <a href=#188 id=188 data-nosnippet>188</a> |
| <a href=#189 id=189 data-nosnippet>189</a><span class="kw">fn </span>validate_snippet( |
| <a href=#190 id=190 data-nosnippet>190</a> snippet: <span class="kw-2">&</span>[String], |
| <a href=#191 id=191 data-nosnippet>191</a> description: <span class="kw-2">&</span>str, |
| <a href=#192 id=192 data-nosnippet>192</a> requires: <span class="kw-2">&</span>[String], |
| <a href=#193 id=193 data-nosnippet>193</a>) -> <span class="prelude-ty">Option</span><(Box<[ModPath]>, String, <span class="prelude-ty">Option</span><Box<str>>)> { |
| <a href=#194 id=194 data-nosnippet>194</a> <span class="kw">let </span><span class="kw-2">mut </span>imports = Vec::with_capacity(requires.len()); |
| <a href=#195 id=195 data-nosnippet>195</a> <span class="kw">for </span>path <span class="kw">in </span>requires.iter() { |
| <a href=#196 id=196 data-nosnippet>196</a> <span class="kw">let </span>use_path = ModPath::from_segments( |
| <a href=#197 id=197 data-nosnippet>197</a> hir::PathKind::Plain, |
| <a href=#198 id=198 data-nosnippet>198</a> path.split(<span class="string">"::"</span>).map(Symbol::intern).map(Name::new_symbol_root), |
| <a href=#199 id=199 data-nosnippet>199</a> ); |
| <a href=#200 id=200 data-nosnippet>200</a> imports.push(use_path); |
| <a href=#201 id=201 data-nosnippet>201</a> } |
| <a href=#202 id=202 data-nosnippet>202</a> <span class="kw">let </span>snippet = snippet.iter().join(<span class="string">"\n"</span>); |
| <a href=#203 id=203 data-nosnippet>203</a> <span class="kw">let </span>description = (!description.is_empty()) |
| <a href=#204 id=204 data-nosnippet>204</a> .then(|| description.split_once(<span class="string">'\n'</span>).map_or(description, |(it, <span class="kw">_</span>)| it)) |
| <a href=#205 id=205 data-nosnippet>205</a> .map(ToOwned::to_owned) |
| <a href=#206 id=206 data-nosnippet>206</a> .map(Into::into); |
| <a href=#207 id=207 data-nosnippet>207</a> <span class="prelude-val">Some</span>((imports.into_boxed_slice(), snippet, description)) |
| <a href=#208 id=208 data-nosnippet>208</a>} |
| </code></pre></div></section></main></body></html> |
