| <!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/mbe/src/parser.rs`."><title>parser.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" crossorigin href="../../static.files/${f}">`).join(""))</script><link rel="stylesheet" href="../../static.files/normalize-9960930a.css"><link rel="stylesheet" href="../../static.files/rustdoc-84e720fa.css"><meta name="rustdoc-vars" data-root-path="../../" data-static-root-path="../../static.files/" data-current-crate="mbe" data-themes="" data-resource-suffix="" data-rustdoc-version="1.89.0 (29483883e 2025-08-04)" data-channel="1.89.0" data-search-js="search-92309212.js" data-settings-js="settings-5514c975.js" ><script src="../../static.files/storage-4e99c027.js"></script><script defer src="../../static.files/src-script-813739b1.js"></script><script defer src="../../src-files.js"></script><script defer src="../../static.files/main-fd3af306.js"></script><noscript><link rel="stylesheet" href="../../static.files/noscript-32bb7600.css"></noscript><link rel="alternate icon" type="image/png" href="../../static.files/favicon-32x32-6580c154.png"><link rel="icon" type="image/svg+xml" href="../../static.files/favicon-044be391.svg"></head><body class="rustdoc src"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"><div class="src-sidebar-title"><h2>Files</h2></div></nav><div class="sidebar-resizer" title="Drag to resize sidebar"></div><main><rustdoc-search></rustdoc-search><section id="main-content" class="content"><div class="main-heading"><h1><div class="sub-heading">mbe/</div>parser.rs</h1><rustdoc-toolbar></rustdoc-toolbar></div><div class="example-wrap digits-3"><pre class="rust"><code><a href=#1 id=1 data-nosnippet>1</a><span class="doccomment">//! Parser recognizes special macro syntax, `$var` and `$(repeat)*`, in token |
| <a href=#2 id=2 data-nosnippet>2</a>//! trees. |
| <a href=#3 id=3 data-nosnippet>3</a> |
| <a href=#4 id=4 data-nosnippet>4</a></span><span class="kw">use </span>std::sync::Arc; |
| <a href=#5 id=5 data-nosnippet>5</a> |
| <a href=#6 id=6 data-nosnippet>6</a><span class="kw">use </span>arrayvec::ArrayVec; |
| <a href=#7 id=7 data-nosnippet>7</a><span class="kw">use </span>intern::{Symbol, sym}; |
| <a href=#8 id=8 data-nosnippet>8</a><span class="kw">use </span>span::{Edition, Span, SyntaxContext}; |
| <a href=#9 id=9 data-nosnippet>9</a><span class="kw">use </span>tt::{ |
| <a href=#10 id=10 data-nosnippet>10</a> MAX_GLUED_PUNCT_LEN, |
| <a href=#11 id=11 data-nosnippet>11</a> iter::{TtElement, TtIter}, |
| <a href=#12 id=12 data-nosnippet>12</a>}; |
| <a href=#13 id=13 data-nosnippet>13</a> |
| <a href=#14 id=14 data-nosnippet>14</a><span class="kw">use </span><span class="kw">crate</span>::ParseError; |
| <a href=#15 id=15 data-nosnippet>15</a> |
| <a href=#16 id=16 data-nosnippet>16</a><span class="doccomment">/// Consider |
| <a href=#17 id=17 data-nosnippet>17</a>/// |
| <a href=#18 id=18 data-nosnippet>18</a>/// ``` |
| <a href=#19 id=19 data-nosnippet>19</a>/// macro_rules! a_macro { |
| <a href=#20 id=20 data-nosnippet>20</a>/// ($x:expr, $y:expr) => ($y * $x) |
| <a href=#21 id=21 data-nosnippet>21</a>/// } |
| <a href=#22 id=22 data-nosnippet>22</a>/// ``` |
| <a href=#23 id=23 data-nosnippet>23</a>/// |
| <a href=#24 id=24 data-nosnippet>24</a>/// Stuff to the left of `=>` is a [`MetaTemplate`] pattern (which is matched |
| <a href=#25 id=25 data-nosnippet>25</a>/// with input). |
| <a href=#26 id=26 data-nosnippet>26</a>/// |
| <a href=#27 id=27 data-nosnippet>27</a>/// Stuff to the right is a [`MetaTemplate`] template which is used to produce |
| <a href=#28 id=28 data-nosnippet>28</a>/// output. |
| <a href=#29 id=29 data-nosnippet>29</a></span><span class="attr">#[derive(Clone, Debug, PartialEq, Eq)] |
| <a href=#30 id=30 data-nosnippet>30</a></span><span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">struct </span>MetaTemplate(<span class="kw">pub</span>(<span class="kw">crate</span>) Box<[Op]>); |
| <a href=#31 id=31 data-nosnippet>31</a> |
| <a href=#32 id=32 data-nosnippet>32</a><span class="kw">impl </span>MetaTemplate { |
| <a href=#33 id=33 data-nosnippet>33</a> <span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">fn </span>parse_pattern( |
| <a href=#34 id=34 data-nosnippet>34</a> edition: <span class="kw">impl </span>Copy + Fn(SyntaxContext) -> Edition, |
| <a href=#35 id=35 data-nosnippet>35</a> pattern: TtIter<<span class="lifetime">'_</span>, Span>, |
| <a href=#36 id=36 data-nosnippet>36</a> ) -> <span class="prelude-ty">Result</span><<span class="self">Self</span>, ParseError> { |
| <a href=#37 id=37 data-nosnippet>37</a> MetaTemplate::parse(edition, pattern, Mode::Pattern) |
| <a href=#38 id=38 data-nosnippet>38</a> } |
| <a href=#39 id=39 data-nosnippet>39</a> |
| <a href=#40 id=40 data-nosnippet>40</a> <span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">fn </span>parse_template( |
| <a href=#41 id=41 data-nosnippet>41</a> edition: <span class="kw">impl </span>Copy + Fn(SyntaxContext) -> Edition, |
| <a href=#42 id=42 data-nosnippet>42</a> template: TtIter<<span class="lifetime">'_</span>, Span>, |
| <a href=#43 id=43 data-nosnippet>43</a> ) -> <span class="prelude-ty">Result</span><<span class="self">Self</span>, ParseError> { |
| <a href=#44 id=44 data-nosnippet>44</a> MetaTemplate::parse(edition, template, Mode::Template) |
| <a href=#45 id=45 data-nosnippet>45</a> } |
| <a href=#46 id=46 data-nosnippet>46</a> |
| <a href=#47 id=47 data-nosnippet>47</a> <span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">fn </span>iter(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="kw">impl </span>Iterator<Item = <span class="kw-2">&</span>Op> { |
| <a href=#48 id=48 data-nosnippet>48</a> <span class="self">self</span>.<span class="number">0</span>.iter() |
| <a href=#49 id=49 data-nosnippet>49</a> } |
| <a href=#50 id=50 data-nosnippet>50</a> |
| <a href=#51 id=51 data-nosnippet>51</a> <span class="kw">fn </span>parse( |
| <a href=#52 id=52 data-nosnippet>52</a> edition: <span class="kw">impl </span>Copy + Fn(SyntaxContext) -> Edition, |
| <a href=#53 id=53 data-nosnippet>53</a> <span class="kw-2">mut </span>src: TtIter<<span class="lifetime">'_</span>, Span>, |
| <a href=#54 id=54 data-nosnippet>54</a> mode: Mode, |
| <a href=#55 id=55 data-nosnippet>55</a> ) -> <span class="prelude-ty">Result</span><<span class="self">Self</span>, ParseError> { |
| <a href=#56 id=56 data-nosnippet>56</a> <span class="kw">let </span><span class="kw-2">mut </span>res = Vec::new(); |
| <a href=#57 id=57 data-nosnippet>57</a> <span class="kw">while let </span><span class="prelude-val">Some</span>(first) = src.peek() { |
| <a href=#58 id=58 data-nosnippet>58</a> <span class="kw">let </span>op = next_op(edition, first, <span class="kw-2">&mut </span>src, mode)<span class="question-mark">?</span>; |
| <a href=#59 id=59 data-nosnippet>59</a> res.push(op); |
| <a href=#60 id=60 data-nosnippet>60</a> } |
| <a href=#61 id=61 data-nosnippet>61</a> |
| <a href=#62 id=62 data-nosnippet>62</a> <span class="prelude-val">Ok</span>(MetaTemplate(res.into_boxed_slice())) |
| <a href=#63 id=63 data-nosnippet>63</a> } |
| <a href=#64 id=64 data-nosnippet>64</a>} |
| <a href=#65 id=65 data-nosnippet>65</a> |
| <a href=#66 id=66 data-nosnippet>66</a><span class="attr">#[derive(Clone, Debug, PartialEq, Eq)] |
| <a href=#67 id=67 data-nosnippet>67</a></span><span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">enum </span>Op { |
| <a href=#68 id=68 data-nosnippet>68</a> Var { |
| <a href=#69 id=69 data-nosnippet>69</a> name: Symbol, |
| <a href=#70 id=70 data-nosnippet>70</a> kind: <span class="prelude-ty">Option</span><MetaVarKind>, |
| <a href=#71 id=71 data-nosnippet>71</a> id: Span, |
| <a href=#72 id=72 data-nosnippet>72</a> }, |
| <a href=#73 id=73 data-nosnippet>73</a> Ignore { |
| <a href=#74 id=74 data-nosnippet>74</a> name: Symbol, |
| <a href=#75 id=75 data-nosnippet>75</a> id: Span, |
| <a href=#76 id=76 data-nosnippet>76</a> }, |
| <a href=#77 id=77 data-nosnippet>77</a> Index { |
| <a href=#78 id=78 data-nosnippet>78</a> depth: usize, |
| <a href=#79 id=79 data-nosnippet>79</a> }, |
| <a href=#80 id=80 data-nosnippet>80</a> Len { |
| <a href=#81 id=81 data-nosnippet>81</a> depth: usize, |
| <a href=#82 id=82 data-nosnippet>82</a> }, |
| <a href=#83 id=83 data-nosnippet>83</a> Count { |
| <a href=#84 id=84 data-nosnippet>84</a> name: Symbol, |
| <a href=#85 id=85 data-nosnippet>85</a> <span class="comment">// FIXME: `usize`` once we drop support for 1.76 |
| <a href=#86 id=86 data-nosnippet>86</a> </span>depth: <span class="prelude-ty">Option</span><usize>, |
| <a href=#87 id=87 data-nosnippet>87</a> }, |
| <a href=#88 id=88 data-nosnippet>88</a> Concat { |
| <a href=#89 id=89 data-nosnippet>89</a> elements: Box<[ConcatMetaVarExprElem]>, |
| <a href=#90 id=90 data-nosnippet>90</a> span: Span, |
| <a href=#91 id=91 data-nosnippet>91</a> }, |
| <a href=#92 id=92 data-nosnippet>92</a> Repeat { |
| <a href=#93 id=93 data-nosnippet>93</a> tokens: MetaTemplate, |
| <a href=#94 id=94 data-nosnippet>94</a> kind: RepeatKind, |
| <a href=#95 id=95 data-nosnippet>95</a> separator: <span class="prelude-ty">Option</span><Arc<Separator>>, |
| <a href=#96 id=96 data-nosnippet>96</a> }, |
| <a href=#97 id=97 data-nosnippet>97</a> Subtree { |
| <a href=#98 id=98 data-nosnippet>98</a> tokens: MetaTemplate, |
| <a href=#99 id=99 data-nosnippet>99</a> delimiter: tt::Delimiter<Span>, |
| <a href=#100 id=100 data-nosnippet>100</a> }, |
| <a href=#101 id=101 data-nosnippet>101</a> Literal(tt::Literal<Span>), |
| <a href=#102 id=102 data-nosnippet>102</a> Punct(Box<ArrayVec<tt::Punct<Span>, MAX_GLUED_PUNCT_LEN>>), |
| <a href=#103 id=103 data-nosnippet>103</a> Ident(tt::Ident<Span>), |
| <a href=#104 id=104 data-nosnippet>104</a>} |
| <a href=#105 id=105 data-nosnippet>105</a> |
| <a href=#106 id=106 data-nosnippet>106</a><span class="attr">#[derive(Clone, Debug, PartialEq, Eq)] |
| <a href=#107 id=107 data-nosnippet>107</a></span><span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">enum </span>ConcatMetaVarExprElem { |
| <a href=#108 id=108 data-nosnippet>108</a> <span class="doccomment">/// There is NO preceding dollar sign, which means that this identifier should be interpreted |
| <a href=#109 id=109 data-nosnippet>109</a> /// as a literal. |
| <a href=#110 id=110 data-nosnippet>110</a> </span>Ident(tt::Ident<Span>), |
| <a href=#111 id=111 data-nosnippet>111</a> <span class="doccomment">/// There is a preceding dollar sign, which means that this identifier should be expanded |
| <a href=#112 id=112 data-nosnippet>112</a> /// and interpreted as a variable. |
| <a href=#113 id=113 data-nosnippet>113</a> </span>Var(tt::Ident<Span>), |
| <a href=#114 id=114 data-nosnippet>114</a> <span class="doccomment">/// For example, a number or a string. |
| <a href=#115 id=115 data-nosnippet>115</a> </span>Literal(tt::Literal<Span>), |
| <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="attr">#[derive(Copy, Clone, Debug, PartialEq, Eq)] |
| <a href=#119 id=119 data-nosnippet>119</a></span><span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">enum </span>RepeatKind { |
| <a href=#120 id=120 data-nosnippet>120</a> ZeroOrMore, |
| <a href=#121 id=121 data-nosnippet>121</a> OneOrMore, |
| <a href=#122 id=122 data-nosnippet>122</a> ZeroOrOne, |
| <a href=#123 id=123 data-nosnippet>123</a>} |
| <a href=#124 id=124 data-nosnippet>124</a> |
| <a href=#125 id=125 data-nosnippet>125</a><span class="attr">#[derive(Copy, Clone, Debug, PartialEq, Eq)] |
| <a href=#126 id=126 data-nosnippet>126</a></span><span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">enum </span>ExprKind { |
| <a href=#127 id=127 data-nosnippet>127</a> <span class="comment">// Matches expressions using the post-edition 2024. Was written using |
| <a href=#128 id=128 data-nosnippet>128</a> // `expr` in edition 2024 or later. |
| <a href=#129 id=129 data-nosnippet>129</a> </span>Expr, |
| <a href=#130 id=130 data-nosnippet>130</a> <span class="comment">// Matches expressions using the pre-edition 2024 rules. |
| <a href=#131 id=131 data-nosnippet>131</a> // Either written using `expr` in edition 2021 or earlier or.was written using `expr_2021`. |
| <a href=#132 id=132 data-nosnippet>132</a> </span>Expr2021, |
| <a href=#133 id=133 data-nosnippet>133</a>} |
| <a href=#134 id=134 data-nosnippet>134</a> |
| <a href=#135 id=135 data-nosnippet>135</a><span class="attr">#[derive(Copy, Clone, Debug, PartialEq, Eq)] |
| <a href=#136 id=136 data-nosnippet>136</a></span><span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">enum </span>MetaVarKind { |
| <a href=#137 id=137 data-nosnippet>137</a> Path, |
| <a href=#138 id=138 data-nosnippet>138</a> Ty, |
| <a href=#139 id=139 data-nosnippet>139</a> Pat, |
| <a href=#140 id=140 data-nosnippet>140</a> PatParam, |
| <a href=#141 id=141 data-nosnippet>141</a> Stmt, |
| <a href=#142 id=142 data-nosnippet>142</a> Block, |
| <a href=#143 id=143 data-nosnippet>143</a> Meta, |
| <a href=#144 id=144 data-nosnippet>144</a> Item, |
| <a href=#145 id=145 data-nosnippet>145</a> Vis, |
| <a href=#146 id=146 data-nosnippet>146</a> Expr(ExprKind), |
| <a href=#147 id=147 data-nosnippet>147</a> Ident, |
| <a href=#148 id=148 data-nosnippet>148</a> Tt, |
| <a href=#149 id=149 data-nosnippet>149</a> Lifetime, |
| <a href=#150 id=150 data-nosnippet>150</a> Literal, |
| <a href=#151 id=151 data-nosnippet>151</a>} |
| <a href=#152 id=152 data-nosnippet>152</a> |
| <a href=#153 id=153 data-nosnippet>153</a><span class="attr">#[derive(Clone, Debug, Eq)] |
| <a href=#154 id=154 data-nosnippet>154</a></span><span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">enum </span>Separator { |
| <a href=#155 id=155 data-nosnippet>155</a> Literal(tt::Literal<Span>), |
| <a href=#156 id=156 data-nosnippet>156</a> Ident(tt::Ident<Span>), |
| <a href=#157 id=157 data-nosnippet>157</a> Puncts(ArrayVec<tt::Punct<Span>, MAX_GLUED_PUNCT_LEN>), |
| <a href=#158 id=158 data-nosnippet>158</a> Lifetime(tt::Punct<Span>, tt::Ident<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="comment">// Note that when we compare a Separator, we just care about its textual value. |
| <a href=#162 id=162 data-nosnippet>162</a></span><span class="kw">impl </span>PartialEq <span class="kw">for </span>Separator { |
| <a href=#163 id=163 data-nosnippet>163</a> <span class="kw">fn </span>eq(<span class="kw-2">&</span><span class="self">self</span>, other: <span class="kw-2">&</span>Separator) -> bool { |
| <a href=#164 id=164 data-nosnippet>164</a> <span class="kw">use </span>Separator::<span class="kw-2">*</span>; |
| <a href=#165 id=165 data-nosnippet>165</a> |
| <a href=#166 id=166 data-nosnippet>166</a> <span class="kw">match </span>(<span class="self">self</span>, other) { |
| <a href=#167 id=167 data-nosnippet>167</a> (Ident(a), Ident(b)) => a.sym == b.sym, |
| <a href=#168 id=168 data-nosnippet>168</a> (Literal(a), Literal(b)) => a.symbol == b.symbol, |
| <a href=#169 id=169 data-nosnippet>169</a> (Puncts(a), Puncts(b)) <span class="kw">if </span>a.len() == b.len() => { |
| <a href=#170 id=170 data-nosnippet>170</a> <span class="kw">let </span>a_iter = a.iter().map(|a| a.char); |
| <a href=#171 id=171 data-nosnippet>171</a> <span class="kw">let </span>b_iter = b.iter().map(|b| b.char); |
| <a href=#172 id=172 data-nosnippet>172</a> a_iter.eq(b_iter) |
| <a href=#173 id=173 data-nosnippet>173</a> } |
| <a href=#174 id=174 data-nosnippet>174</a> (Lifetime(<span class="kw">_</span>, a), Lifetime(<span class="kw">_</span>, b)) => a.sym == b.sym, |
| <a href=#175 id=175 data-nosnippet>175</a> <span class="kw">_ </span>=> <span class="bool-val">false</span>, |
| <a href=#176 id=176 data-nosnippet>176</a> } |
| <a href=#177 id=177 data-nosnippet>177</a> } |
| <a href=#178 id=178 data-nosnippet>178</a>} |
| <a href=#179 id=179 data-nosnippet>179</a> |
| <a href=#180 id=180 data-nosnippet>180</a><span class="attr">#[derive(Clone, Copy)] |
| <a href=#181 id=181 data-nosnippet>181</a></span><span class="kw">enum </span>Mode { |
| <a href=#182 id=182 data-nosnippet>182</a> Pattern, |
| <a href=#183 id=183 data-nosnippet>183</a> Template, |
| <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="kw">fn </span>next_op( |
| <a href=#187 id=187 data-nosnippet>187</a> edition: <span class="kw">impl </span>Copy + Fn(SyntaxContext) -> Edition, |
| <a href=#188 id=188 data-nosnippet>188</a> first_peeked: TtElement<<span class="lifetime">'_</span>, Span>, |
| <a href=#189 id=189 data-nosnippet>189</a> src: <span class="kw-2">&mut </span>TtIter<<span class="lifetime">'_</span>, Span>, |
| <a href=#190 id=190 data-nosnippet>190</a> mode: Mode, |
| <a href=#191 id=191 data-nosnippet>191</a>) -> <span class="prelude-ty">Result</span><Op, ParseError> { |
| <a href=#192 id=192 data-nosnippet>192</a> <span class="kw">let </span>res = <span class="kw">match </span>first_peeked { |
| <a href=#193 id=193 data-nosnippet>193</a> TtElement::Leaf(tt::Leaf::Punct(p @ tt::Punct { char: <span class="string">'$'</span>, .. })) => { |
| <a href=#194 id=194 data-nosnippet>194</a> src.next().expect(<span class="string">"first token already peeked"</span>); |
| <a href=#195 id=195 data-nosnippet>195</a> <span class="comment">// Note that the '$' itself is a valid token inside macro_rules. |
| <a href=#196 id=196 data-nosnippet>196</a> </span><span class="kw">let </span>second = <span class="kw">match </span>src.next() { |
| <a href=#197 id=197 data-nosnippet>197</a> <span class="prelude-val">None </span>=> { |
| <a href=#198 id=198 data-nosnippet>198</a> <span class="kw">return </span><span class="prelude-val">Ok</span>(Op::Punct({ |
| <a href=#199 id=199 data-nosnippet>199</a> <span class="kw">let </span><span class="kw-2">mut </span>res = ArrayVec::new(); |
| <a href=#200 id=200 data-nosnippet>200</a> res.push(<span class="kw-2">*</span>p); |
| <a href=#201 id=201 data-nosnippet>201</a> Box::new(res) |
| <a href=#202 id=202 data-nosnippet>202</a> })); |
| <a href=#203 id=203 data-nosnippet>203</a> } |
| <a href=#204 id=204 data-nosnippet>204</a> <span class="prelude-val">Some</span>(it) => it, |
| <a href=#205 id=205 data-nosnippet>205</a> }; |
| <a href=#206 id=206 data-nosnippet>206</a> <span class="kw">match </span>second { |
| <a href=#207 id=207 data-nosnippet>207</a> TtElement::Subtree(subtree, <span class="kw-2">mut </span>subtree_iter) => <span class="kw">match </span>subtree.delimiter.kind { |
| <a href=#208 id=208 data-nosnippet>208</a> tt::DelimiterKind::Parenthesis => { |
| <a href=#209 id=209 data-nosnippet>209</a> <span class="kw">let </span>(separator, kind) = parse_repeat(src)<span class="question-mark">?</span>; |
| <a href=#210 id=210 data-nosnippet>210</a> <span class="kw">let </span>tokens = MetaTemplate::parse(edition, subtree_iter, mode)<span class="question-mark">?</span>; |
| <a href=#211 id=211 data-nosnippet>211</a> Op::Repeat { tokens, separator: separator.map(Arc::new), kind } |
| <a href=#212 id=212 data-nosnippet>212</a> } |
| <a href=#213 id=213 data-nosnippet>213</a> tt::DelimiterKind::Brace => <span class="kw">match </span>mode { |
| <a href=#214 id=214 data-nosnippet>214</a> Mode::Template => parse_metavar_expr(<span class="kw-2">&mut </span>subtree_iter).map_err(|()| { |
| <a href=#215 id=215 data-nosnippet>215</a> ParseError::unexpected(<span class="string">"invalid metavariable expression"</span>) |
| <a href=#216 id=216 data-nosnippet>216</a> })<span class="question-mark">?</span>, |
| <a href=#217 id=217 data-nosnippet>217</a> Mode::Pattern => { |
| <a href=#218 id=218 data-nosnippet>218</a> <span class="kw">return </span><span class="prelude-val">Err</span>(ParseError::unexpected( |
| <a href=#219 id=219 data-nosnippet>219</a> <span class="string">"`${}` metavariable expressions are not allowed in matchers"</span>, |
| <a href=#220 id=220 data-nosnippet>220</a> )); |
| <a href=#221 id=221 data-nosnippet>221</a> } |
| <a href=#222 id=222 data-nosnippet>222</a> }, |
| <a href=#223 id=223 data-nosnippet>223</a> <span class="kw">_ </span>=> { |
| <a href=#224 id=224 data-nosnippet>224</a> <span class="kw">return </span><span class="prelude-val">Err</span>(ParseError::expected( |
| <a href=#225 id=225 data-nosnippet>225</a> <span class="string">"expected `$()` repetition or `${}` expression"</span>, |
| <a href=#226 id=226 data-nosnippet>226</a> )); |
| <a href=#227 id=227 data-nosnippet>227</a> } |
| <a href=#228 id=228 data-nosnippet>228</a> }, |
| <a href=#229 id=229 data-nosnippet>229</a> TtElement::Leaf(leaf) => <span class="kw">match </span>leaf { |
| <a href=#230 id=230 data-nosnippet>230</a> tt::Leaf::Ident(ident) <span class="kw">if </span>ident.sym == sym::crate_ => { |
| <a href=#231 id=231 data-nosnippet>231</a> <span class="comment">// We simply produce identifier `$crate` here. And it will be resolved when lowering ast to Path. |
| <a href=#232 id=232 data-nosnippet>232</a> </span>Op::Ident(tt::Ident { |
| <a href=#233 id=233 data-nosnippet>233</a> sym: sym::dollar_crate, |
| <a href=#234 id=234 data-nosnippet>234</a> span: ident.span, |
| <a href=#235 id=235 data-nosnippet>235</a> is_raw: tt::IdentIsRaw::No, |
| <a href=#236 id=236 data-nosnippet>236</a> }) |
| <a href=#237 id=237 data-nosnippet>237</a> } |
| <a href=#238 id=238 data-nosnippet>238</a> tt::Leaf::Ident(ident) => { |
| <a href=#239 id=239 data-nosnippet>239</a> <span class="kw">let </span>kind = eat_fragment_kind(edition, src, mode)<span class="question-mark">?</span>; |
| <a href=#240 id=240 data-nosnippet>240</a> <span class="kw">let </span>name = ident.sym.clone(); |
| <a href=#241 id=241 data-nosnippet>241</a> <span class="kw">let </span>id = ident.span; |
| <a href=#242 id=242 data-nosnippet>242</a> Op::Var { name, kind, id } |
| <a href=#243 id=243 data-nosnippet>243</a> } |
| <a href=#244 id=244 data-nosnippet>244</a> tt::Leaf::Literal(lit) <span class="kw">if </span>is_boolean_literal(lit) => { |
| <a href=#245 id=245 data-nosnippet>245</a> <span class="kw">let </span>kind = eat_fragment_kind(edition, src, mode)<span class="question-mark">?</span>; |
| <a href=#246 id=246 data-nosnippet>246</a> <span class="kw">let </span>name = lit.symbol.clone(); |
| <a href=#247 id=247 data-nosnippet>247</a> <span class="kw">let </span>id = lit.span; |
| <a href=#248 id=248 data-nosnippet>248</a> Op::Var { name, kind, id } |
| <a href=#249 id=249 data-nosnippet>249</a> } |
| <a href=#250 id=250 data-nosnippet>250</a> tt::Leaf::Punct(punct @ tt::Punct { char: <span class="string">'$'</span>, .. }) => <span class="kw">match </span>mode { |
| <a href=#251 id=251 data-nosnippet>251</a> Mode::Pattern => { |
| <a href=#252 id=252 data-nosnippet>252</a> <span class="kw">return </span><span class="prelude-val">Err</span>(ParseError::unexpected( |
| <a href=#253 id=253 data-nosnippet>253</a> <span class="string">"`$$` is not allowed on the pattern side"</span>, |
| <a href=#254 id=254 data-nosnippet>254</a> )); |
| <a href=#255 id=255 data-nosnippet>255</a> } |
| <a href=#256 id=256 data-nosnippet>256</a> Mode::Template => Op::Punct({ |
| <a href=#257 id=257 data-nosnippet>257</a> <span class="kw">let </span><span class="kw-2">mut </span>res = ArrayVec::new(); |
| <a href=#258 id=258 data-nosnippet>258</a> res.push(<span class="kw-2">*</span>punct); |
| <a href=#259 id=259 data-nosnippet>259</a> Box::new(res) |
| <a href=#260 id=260 data-nosnippet>260</a> }), |
| <a href=#261 id=261 data-nosnippet>261</a> }, |
| <a href=#262 id=262 data-nosnippet>262</a> tt::Leaf::Punct(<span class="kw">_</span>) | tt::Leaf::Literal(<span class="kw">_</span>) => { |
| <a href=#263 id=263 data-nosnippet>263</a> <span class="kw">return </span><span class="prelude-val">Err</span>(ParseError::expected(<span class="string">"expected ident"</span>)); |
| <a href=#264 id=264 data-nosnippet>264</a> } |
| <a href=#265 id=265 data-nosnippet>265</a> }, |
| <a href=#266 id=266 data-nosnippet>266</a> } |
| <a href=#267 id=267 data-nosnippet>267</a> } |
| <a href=#268 id=268 data-nosnippet>268</a> |
| <a href=#269 id=269 data-nosnippet>269</a> TtElement::Leaf(tt::Leaf::Literal(it)) => { |
| <a href=#270 id=270 data-nosnippet>270</a> src.next().expect(<span class="string">"first token already peeked"</span>); |
| <a href=#271 id=271 data-nosnippet>271</a> Op::Literal(it.clone()) |
| <a href=#272 id=272 data-nosnippet>272</a> } |
| <a href=#273 id=273 data-nosnippet>273</a> |
| <a href=#274 id=274 data-nosnippet>274</a> TtElement::Leaf(tt::Leaf::Ident(it)) => { |
| <a href=#275 id=275 data-nosnippet>275</a> src.next().expect(<span class="string">"first token already peeked"</span>); |
| <a href=#276 id=276 data-nosnippet>276</a> Op::Ident(it.clone()) |
| <a href=#277 id=277 data-nosnippet>277</a> } |
| <a href=#278 id=278 data-nosnippet>278</a> |
| <a href=#279 id=279 data-nosnippet>279</a> TtElement::Leaf(tt::Leaf::Punct(<span class="kw">_</span>)) => { |
| <a href=#280 id=280 data-nosnippet>280</a> <span class="comment">// There's at least one punct so this shouldn't fail. |
| <a href=#281 id=281 data-nosnippet>281</a> </span><span class="kw">let </span>puncts = src.expect_glued_punct().unwrap(); |
| <a href=#282 id=282 data-nosnippet>282</a> Op::Punct(Box::new(puncts)) |
| <a href=#283 id=283 data-nosnippet>283</a> } |
| <a href=#284 id=284 data-nosnippet>284</a> |
| <a href=#285 id=285 data-nosnippet>285</a> TtElement::Subtree(subtree, subtree_iter) => { |
| <a href=#286 id=286 data-nosnippet>286</a> src.next().expect(<span class="string">"first token already peeked"</span>); |
| <a href=#287 id=287 data-nosnippet>287</a> <span class="kw">let </span>tokens = MetaTemplate::parse(edition, subtree_iter, mode)<span class="question-mark">?</span>; |
| <a href=#288 id=288 data-nosnippet>288</a> Op::Subtree { tokens, delimiter: subtree.delimiter } |
| <a href=#289 id=289 data-nosnippet>289</a> } |
| <a href=#290 id=290 data-nosnippet>290</a> }; |
| <a href=#291 id=291 data-nosnippet>291</a> <span class="prelude-val">Ok</span>(res) |
| <a href=#292 id=292 data-nosnippet>292</a>} |
| <a href=#293 id=293 data-nosnippet>293</a> |
| <a href=#294 id=294 data-nosnippet>294</a><span class="kw">fn </span>eat_fragment_kind( |
| <a href=#295 id=295 data-nosnippet>295</a> edition: <span class="kw">impl </span>Copy + Fn(SyntaxContext) -> Edition, |
| <a href=#296 id=296 data-nosnippet>296</a> src: <span class="kw-2">&mut </span>TtIter<<span class="lifetime">'_</span>, Span>, |
| <a href=#297 id=297 data-nosnippet>297</a> mode: Mode, |
| <a href=#298 id=298 data-nosnippet>298</a>) -> <span class="prelude-ty">Result</span><<span class="prelude-ty">Option</span><MetaVarKind>, ParseError> { |
| <a href=#299 id=299 data-nosnippet>299</a> <span class="kw">if let </span>Mode::Pattern = mode { |
| <a href=#300 id=300 data-nosnippet>300</a> src.expect_char(<span class="string">':'</span>).map_err(|()| ParseError::unexpected(<span class="string">"missing fragment specifier"</span>))<span class="question-mark">?</span>; |
| <a href=#301 id=301 data-nosnippet>301</a> <span class="kw">let </span>ident = src |
| <a href=#302 id=302 data-nosnippet>302</a> .expect_ident() |
| <a href=#303 id=303 data-nosnippet>303</a> .map_err(|()| ParseError::unexpected(<span class="string">"missing fragment specifier"</span>))<span class="question-mark">?</span>; |
| <a href=#304 id=304 data-nosnippet>304</a> <span class="kw">let </span>kind = <span class="kw">match </span>ident.sym.as_str() { |
| <a href=#305 id=305 data-nosnippet>305</a> <span class="string">"path" </span>=> MetaVarKind::Path, |
| <a href=#306 id=306 data-nosnippet>306</a> <span class="string">"ty" </span>=> MetaVarKind::Ty, |
| <a href=#307 id=307 data-nosnippet>307</a> <span class="string">"pat" </span>=> { |
| <a href=#308 id=308 data-nosnippet>308</a> <span class="kw">if </span>edition(ident.span.ctx).at_least_2021() { |
| <a href=#309 id=309 data-nosnippet>309</a> MetaVarKind::Pat |
| <a href=#310 id=310 data-nosnippet>310</a> } <span class="kw">else </span>{ |
| <a href=#311 id=311 data-nosnippet>311</a> MetaVarKind::PatParam |
| <a href=#312 id=312 data-nosnippet>312</a> } |
| <a href=#313 id=313 data-nosnippet>313</a> } |
| <a href=#314 id=314 data-nosnippet>314</a> <span class="string">"pat_param" </span>=> MetaVarKind::PatParam, |
| <a href=#315 id=315 data-nosnippet>315</a> <span class="string">"stmt" </span>=> MetaVarKind::Stmt, |
| <a href=#316 id=316 data-nosnippet>316</a> <span class="string">"block" </span>=> MetaVarKind::Block, |
| <a href=#317 id=317 data-nosnippet>317</a> <span class="string">"meta" </span>=> MetaVarKind::Meta, |
| <a href=#318 id=318 data-nosnippet>318</a> <span class="string">"item" </span>=> MetaVarKind::Item, |
| <a href=#319 id=319 data-nosnippet>319</a> <span class="string">"vis" </span>=> MetaVarKind::Vis, |
| <a href=#320 id=320 data-nosnippet>320</a> <span class="string">"expr" </span>=> { |
| <a href=#321 id=321 data-nosnippet>321</a> <span class="kw">if </span>edition(ident.span.ctx).at_least_2024() { |
| <a href=#322 id=322 data-nosnippet>322</a> MetaVarKind::Expr(ExprKind::Expr) |
| <a href=#323 id=323 data-nosnippet>323</a> } <span class="kw">else </span>{ |
| <a href=#324 id=324 data-nosnippet>324</a> MetaVarKind::Expr(ExprKind::Expr2021) |
| <a href=#325 id=325 data-nosnippet>325</a> } |
| <a href=#326 id=326 data-nosnippet>326</a> } |
| <a href=#327 id=327 data-nosnippet>327</a> <span class="string">"expr_2021" </span>=> MetaVarKind::Expr(ExprKind::Expr2021), |
| <a href=#328 id=328 data-nosnippet>328</a> <span class="string">"ident" </span>=> MetaVarKind::Ident, |
| <a href=#329 id=329 data-nosnippet>329</a> <span class="string">"tt" </span>=> MetaVarKind::Tt, |
| <a href=#330 id=330 data-nosnippet>330</a> <span class="string">"lifetime" </span>=> MetaVarKind::Lifetime, |
| <a href=#331 id=331 data-nosnippet>331</a> <span class="string">"literal" </span>=> MetaVarKind::Literal, |
| <a href=#332 id=332 data-nosnippet>332</a> <span class="kw">_ </span>=> <span class="kw">return </span><span class="prelude-val">Ok</span>(<span class="prelude-val">None</span>), |
| <a href=#333 id=333 data-nosnippet>333</a> }; |
| <a href=#334 id=334 data-nosnippet>334</a> <span class="kw">return </span><span class="prelude-val">Ok</span>(<span class="prelude-val">Some</span>(kind)); |
| <a href=#335 id=335 data-nosnippet>335</a> }; |
| <a href=#336 id=336 data-nosnippet>336</a> <span class="prelude-val">Ok</span>(<span class="prelude-val">None</span>) |
| <a href=#337 id=337 data-nosnippet>337</a>} |
| <a href=#338 id=338 data-nosnippet>338</a> |
| <a href=#339 id=339 data-nosnippet>339</a><span class="kw">fn </span>is_boolean_literal(lit: <span class="kw-2">&</span>tt::Literal<Span>) -> bool { |
| <a href=#340 id=340 data-nosnippet>340</a> <span class="macro">matches!</span>(lit.symbol.as_str(), <span class="string">"true" </span>| <span class="string">"false"</span>) |
| <a href=#341 id=341 data-nosnippet>341</a>} |
| <a href=#342 id=342 data-nosnippet>342</a> |
| <a href=#343 id=343 data-nosnippet>343</a><span class="kw">fn </span>parse_repeat(src: <span class="kw-2">&mut </span>TtIter<<span class="lifetime">'_</span>, Span>) -> <span class="prelude-ty">Result</span><(<span class="prelude-ty">Option</span><Separator>, RepeatKind), ParseError> { |
| <a href=#344 id=344 data-nosnippet>344</a> <span class="kw">let </span><span class="kw-2">mut </span>separator = Separator::Puncts(ArrayVec::new()); |
| <a href=#345 id=345 data-nosnippet>345</a> <span class="kw">for </span>tt <span class="kw">in </span>src { |
| <a href=#346 id=346 data-nosnippet>346</a> <span class="kw">let </span>tt = <span class="kw">match </span>tt { |
| <a href=#347 id=347 data-nosnippet>347</a> TtElement::Leaf(leaf) => leaf, |
| <a href=#348 id=348 data-nosnippet>348</a> TtElement::Subtree(..) => <span class="kw">return </span><span class="prelude-val">Err</span>(ParseError::InvalidRepeat), |
| <a href=#349 id=349 data-nosnippet>349</a> }; |
| <a href=#350 id=350 data-nosnippet>350</a> <span class="kw">let </span>has_sep = <span class="kw">match </span><span class="kw-2">&</span>separator { |
| <a href=#351 id=351 data-nosnippet>351</a> Separator::Puncts(puncts) => !puncts.is_empty(), |
| <a href=#352 id=352 data-nosnippet>352</a> <span class="kw">_ </span>=> <span class="bool-val">true</span>, |
| <a href=#353 id=353 data-nosnippet>353</a> }; |
| <a href=#354 id=354 data-nosnippet>354</a> <span class="kw">match </span>tt { |
| <a href=#355 id=355 data-nosnippet>355</a> tt::Leaf::Ident(ident) => <span class="kw">match </span>separator { |
| <a href=#356 id=356 data-nosnippet>356</a> Separator::Puncts(puncts) <span class="kw">if </span>puncts.is_empty() => { |
| <a href=#357 id=357 data-nosnippet>357</a> separator = Separator::Ident(ident.clone()); |
| <a href=#358 id=358 data-nosnippet>358</a> } |
| <a href=#359 id=359 data-nosnippet>359</a> Separator::Puncts(puncts) => <span class="kw">match </span>puncts.as_slice() { |
| <a href=#360 id=360 data-nosnippet>360</a> [tt::Punct { char: <span class="string">'\''</span>, .. }] => { |
| <a href=#361 id=361 data-nosnippet>361</a> separator = Separator::Lifetime(puncts[<span class="number">0</span>], ident.clone()); |
| <a href=#362 id=362 data-nosnippet>362</a> } |
| <a href=#363 id=363 data-nosnippet>363</a> <span class="kw">_ </span>=> <span class="kw">return </span><span class="prelude-val">Err</span>(ParseError::InvalidRepeat), |
| <a href=#364 id=364 data-nosnippet>364</a> }, |
| <a href=#365 id=365 data-nosnippet>365</a> <span class="kw">_ </span>=> <span class="kw">return </span><span class="prelude-val">Err</span>(ParseError::InvalidRepeat), |
| <a href=#366 id=366 data-nosnippet>366</a> }, |
| <a href=#367 id=367 data-nosnippet>367</a> tt::Leaf::Literal(<span class="kw">_</span>) <span class="kw">if </span>has_sep => <span class="kw">return </span><span class="prelude-val">Err</span>(ParseError::InvalidRepeat), |
| <a href=#368 id=368 data-nosnippet>368</a> tt::Leaf::Literal(lit) => separator = Separator::Literal(lit.clone()), |
| <a href=#369 id=369 data-nosnippet>369</a> tt::Leaf::Punct(punct) => { |
| <a href=#370 id=370 data-nosnippet>370</a> <span class="kw">let </span>repeat_kind = <span class="kw">match </span>punct.char { |
| <a href=#371 id=371 data-nosnippet>371</a> <span class="string">'*' </span>=> RepeatKind::ZeroOrMore, |
| <a href=#372 id=372 data-nosnippet>372</a> <span class="string">'+' </span>=> RepeatKind::OneOrMore, |
| <a href=#373 id=373 data-nosnippet>373</a> <span class="string">'?' </span>=> RepeatKind::ZeroOrOne, |
| <a href=#374 id=374 data-nosnippet>374</a> <span class="kw">_ </span>=> <span class="kw">match </span><span class="kw-2">&mut </span>separator { |
| <a href=#375 id=375 data-nosnippet>375</a> Separator::Puncts(puncts) <span class="kw">if </span>puncts.len() < <span class="number">3 </span>=> { |
| <a href=#376 id=376 data-nosnippet>376</a> puncts.push(<span class="kw-2">*</span>punct); |
| <a href=#377 id=377 data-nosnippet>377</a> <span class="kw">continue</span>; |
| <a href=#378 id=378 data-nosnippet>378</a> } |
| <a href=#379 id=379 data-nosnippet>379</a> <span class="kw">_ </span>=> <span class="kw">return </span><span class="prelude-val">Err</span>(ParseError::InvalidRepeat), |
| <a href=#380 id=380 data-nosnippet>380</a> }, |
| <a href=#381 id=381 data-nosnippet>381</a> }; |
| <a href=#382 id=382 data-nosnippet>382</a> <span class="kw">return </span><span class="prelude-val">Ok</span>((has_sep.then_some(separator), repeat_kind)); |
| <a href=#383 id=383 data-nosnippet>383</a> } |
| <a href=#384 id=384 data-nosnippet>384</a> } |
| <a href=#385 id=385 data-nosnippet>385</a> } |
| <a href=#386 id=386 data-nosnippet>386</a> <span class="prelude-val">Err</span>(ParseError::InvalidRepeat) |
| <a href=#387 id=387 data-nosnippet>387</a>} |
| <a href=#388 id=388 data-nosnippet>388</a> |
| <a href=#389 id=389 data-nosnippet>389</a><span class="kw">fn </span>parse_metavar_expr(src: <span class="kw-2">&mut </span>TtIter<<span class="lifetime">'_</span>, Span>) -> <span class="prelude-ty">Result</span><Op, ()> { |
| <a href=#390 id=390 data-nosnippet>390</a> <span class="kw">let </span>func = src.expect_ident()<span class="question-mark">?</span>; |
| <a href=#391 id=391 data-nosnippet>391</a> <span class="kw">let </span>(args, <span class="kw-2">mut </span>args_iter) = src.expect_subtree()<span class="question-mark">?</span>; |
| <a href=#392 id=392 data-nosnippet>392</a> |
| <a href=#393 id=393 data-nosnippet>393</a> <span class="kw">if </span>args.delimiter.kind != tt::DelimiterKind::Parenthesis { |
| <a href=#394 id=394 data-nosnippet>394</a> <span class="kw">return </span><span class="prelude-val">Err</span>(()); |
| <a href=#395 id=395 data-nosnippet>395</a> } |
| <a href=#396 id=396 data-nosnippet>396</a> |
| <a href=#397 id=397 data-nosnippet>397</a> <span class="kw">let </span>op = <span class="kw">match </span><span class="kw-2">&</span>func.sym { |
| <a href=#398 id=398 data-nosnippet>398</a> s <span class="kw">if </span>sym::ignore == <span class="kw-2">*</span>s => { |
| <a href=#399 id=399 data-nosnippet>399</a> args_iter.expect_dollar()<span class="question-mark">?</span>; |
| <a href=#400 id=400 data-nosnippet>400</a> <span class="kw">let </span>ident = args_iter.expect_ident()<span class="question-mark">?</span>; |
| <a href=#401 id=401 data-nosnippet>401</a> Op::Ignore { name: ident.sym.clone(), id: ident.span } |
| <a href=#402 id=402 data-nosnippet>402</a> } |
| <a href=#403 id=403 data-nosnippet>403</a> s <span class="kw">if </span>sym::index == <span class="kw-2">*</span>s => Op::Index { depth: parse_depth(<span class="kw-2">&mut </span>args_iter)<span class="question-mark">? </span>}, |
| <a href=#404 id=404 data-nosnippet>404</a> s <span class="kw">if </span>sym::len == <span class="kw-2">*</span>s => Op::Len { depth: parse_depth(<span class="kw-2">&mut </span>args_iter)<span class="question-mark">? </span>}, |
| <a href=#405 id=405 data-nosnippet>405</a> s <span class="kw">if </span>sym::count == <span class="kw-2">*</span>s => { |
| <a href=#406 id=406 data-nosnippet>406</a> args_iter.expect_dollar()<span class="question-mark">?</span>; |
| <a href=#407 id=407 data-nosnippet>407</a> <span class="kw">let </span>ident = args_iter.expect_ident()<span class="question-mark">?</span>; |
| <a href=#408 id=408 data-nosnippet>408</a> <span class="kw">let </span>depth = <span class="kw">if </span>try_eat_comma(<span class="kw-2">&mut </span>args_iter) { |
| <a href=#409 id=409 data-nosnippet>409</a> <span class="prelude-val">Some</span>(parse_depth(<span class="kw-2">&mut </span>args_iter)<span class="question-mark">?</span>) |
| <a href=#410 id=410 data-nosnippet>410</a> } <span class="kw">else </span>{ |
| <a href=#411 id=411 data-nosnippet>411</a> <span class="prelude-val">None |
| <a href=#412 id=412 data-nosnippet>412</a> </span>}; |
| <a href=#413 id=413 data-nosnippet>413</a> Op::Count { name: ident.sym.clone(), depth } |
| <a href=#414 id=414 data-nosnippet>414</a> } |
| <a href=#415 id=415 data-nosnippet>415</a> s <span class="kw">if </span>sym::concat == <span class="kw-2">*</span>s => { |
| <a href=#416 id=416 data-nosnippet>416</a> <span class="kw">let </span><span class="kw-2">mut </span>elements = Vec::new(); |
| <a href=#417 id=417 data-nosnippet>417</a> <span class="kw">while let </span><span class="prelude-val">Some</span>(next) = args_iter.peek() { |
| <a href=#418 id=418 data-nosnippet>418</a> <span class="kw">let </span>element = <span class="kw">if let </span>TtElement::Leaf(tt::Leaf::Literal(lit)) = next { |
| <a href=#419 id=419 data-nosnippet>419</a> args_iter.next().expect(<span class="string">"already peeked"</span>); |
| <a href=#420 id=420 data-nosnippet>420</a> ConcatMetaVarExprElem::Literal(lit.clone()) |
| <a href=#421 id=421 data-nosnippet>421</a> } <span class="kw">else </span>{ |
| <a href=#422 id=422 data-nosnippet>422</a> <span class="kw">let </span>is_var = try_eat_dollar(<span class="kw-2">&mut </span>args_iter); |
| <a href=#423 id=423 data-nosnippet>423</a> <span class="kw">let </span>ident = args_iter.expect_ident_or_underscore()<span class="question-mark">?</span>.clone(); |
| <a href=#424 id=424 data-nosnippet>424</a> |
| <a href=#425 id=425 data-nosnippet>425</a> <span class="kw">if </span>is_var { |
| <a href=#426 id=426 data-nosnippet>426</a> ConcatMetaVarExprElem::Var(ident) |
| <a href=#427 id=427 data-nosnippet>427</a> } <span class="kw">else </span>{ |
| <a href=#428 id=428 data-nosnippet>428</a> ConcatMetaVarExprElem::Ident(ident) |
| <a href=#429 id=429 data-nosnippet>429</a> } |
| <a href=#430 id=430 data-nosnippet>430</a> }; |
| <a href=#431 id=431 data-nosnippet>431</a> elements.push(element); |
| <a href=#432 id=432 data-nosnippet>432</a> <span class="kw">if </span>!args_iter.is_empty() { |
| <a href=#433 id=433 data-nosnippet>433</a> args_iter.expect_comma()<span class="question-mark">?</span>; |
| <a href=#434 id=434 data-nosnippet>434</a> } |
| <a href=#435 id=435 data-nosnippet>435</a> } |
| <a href=#436 id=436 data-nosnippet>436</a> <span class="kw">if </span>elements.len() < <span class="number">2 </span>{ |
| <a href=#437 id=437 data-nosnippet>437</a> <span class="kw">return </span><span class="prelude-val">Err</span>(()); |
| <a href=#438 id=438 data-nosnippet>438</a> } |
| <a href=#439 id=439 data-nosnippet>439</a> Op::Concat { elements: elements.into_boxed_slice(), span: func.span } |
| <a href=#440 id=440 data-nosnippet>440</a> } |
| <a href=#441 id=441 data-nosnippet>441</a> <span class="kw">_ </span>=> <span class="kw">return </span><span class="prelude-val">Err</span>(()), |
| <a href=#442 id=442 data-nosnippet>442</a> }; |
| <a href=#443 id=443 data-nosnippet>443</a> |
| <a href=#444 id=444 data-nosnippet>444</a> <span class="kw">if </span>args_iter.next().is_some() { |
| <a href=#445 id=445 data-nosnippet>445</a> <span class="kw">return </span><span class="prelude-val">Err</span>(()); |
| <a href=#446 id=446 data-nosnippet>446</a> } |
| <a href=#447 id=447 data-nosnippet>447</a> |
| <a href=#448 id=448 data-nosnippet>448</a> <span class="prelude-val">Ok</span>(op) |
| <a href=#449 id=449 data-nosnippet>449</a>} |
| <a href=#450 id=450 data-nosnippet>450</a> |
| <a href=#451 id=451 data-nosnippet>451</a><span class="kw">fn </span>parse_depth(src: <span class="kw-2">&mut </span>TtIter<<span class="lifetime">'_</span>, Span>) -> <span class="prelude-ty">Result</span><usize, ()> { |
| <a href=#452 id=452 data-nosnippet>452</a> <span class="kw">if </span>src.is_empty() { |
| <a href=#453 id=453 data-nosnippet>453</a> <span class="prelude-val">Ok</span>(<span class="number">0</span>) |
| <a href=#454 id=454 data-nosnippet>454</a> } <span class="kw">else if let </span>tt::Leaf::Literal(tt::Literal { symbol: text, suffix: <span class="prelude-val">None</span>, .. }) = |
| <a href=#455 id=455 data-nosnippet>455</a> src.expect_literal()<span class="question-mark">? |
| <a href=#456 id=456 data-nosnippet>456</a> </span>{ |
| <a href=#457 id=457 data-nosnippet>457</a> <span class="comment">// Suffixes are not allowed. |
| <a href=#458 id=458 data-nosnippet>458</a> </span>text.as_str().parse().map_err(|<span class="kw">_</span>| ()) |
| <a href=#459 id=459 data-nosnippet>459</a> } <span class="kw">else </span>{ |
| <a href=#460 id=460 data-nosnippet>460</a> <span class="prelude-val">Err</span>(()) |
| <a href=#461 id=461 data-nosnippet>461</a> } |
| <a href=#462 id=462 data-nosnippet>462</a>} |
| <a href=#463 id=463 data-nosnippet>463</a> |
| <a href=#464 id=464 data-nosnippet>464</a><span class="kw">fn </span>try_eat_comma(src: <span class="kw-2">&mut </span>TtIter<<span class="lifetime">'_</span>, Span>) -> bool { |
| <a href=#465 id=465 data-nosnippet>465</a> <span class="kw">if let </span><span class="prelude-val">Some</span>(TtElement::Leaf(tt::Leaf::Punct(tt::Punct { char: <span class="string">','</span>, .. }))) = src.peek() { |
| <a href=#466 id=466 data-nosnippet>466</a> <span class="kw">let _ </span>= src.next(); |
| <a href=#467 id=467 data-nosnippet>467</a> <span class="kw">return </span><span class="bool-val">true</span>; |
| <a href=#468 id=468 data-nosnippet>468</a> } |
| <a href=#469 id=469 data-nosnippet>469</a> <span class="bool-val">false |
| <a href=#470 id=470 data-nosnippet>470</a></span>} |
| <a href=#471 id=471 data-nosnippet>471</a> |
| <a href=#472 id=472 data-nosnippet>472</a><span class="kw">fn </span>try_eat_dollar(src: <span class="kw-2">&mut </span>TtIter<<span class="lifetime">'_</span>, Span>) -> bool { |
| <a href=#473 id=473 data-nosnippet>473</a> <span class="kw">if let </span><span class="prelude-val">Some</span>(TtElement::Leaf(tt::Leaf::Punct(tt::Punct { char: <span class="string">'$'</span>, .. }))) = src.peek() { |
| <a href=#474 id=474 data-nosnippet>474</a> <span class="kw">let _ </span>= src.next(); |
| <a href=#475 id=475 data-nosnippet>475</a> <span class="kw">return </span><span class="bool-val">true</span>; |
| <a href=#476 id=476 data-nosnippet>476</a> } |
| <a href=#477 id=477 data-nosnippet>477</a> <span class="bool-val">false |
| <a href=#478 id=478 data-nosnippet>478</a></span>}</code></pre></div></section></main></body></html> |
