| <!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/tt/src/iter.rs`."><title>iter.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-aa0817cf.css"><meta name="rustdoc-vars" data-root-path="../../" data-static-root-path="../../static.files/" data-current-crate="tt" data-themes="" data-resource-suffix="" data-rustdoc-version="1.90.0 (1159e78c4 2025-09-14)" data-channel="1.90.0" data-search-js="search-fa3e91e5.js" data-settings-js="settings-5514c975.js" ><script src="../../static.files/storage-68b7e25d.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-eebb9057.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">tt/</div>iter.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">//! A "Parser" structure for token trees. We use this when parsing a declarative |
| <a href=#2 id=2 data-nosnippet>2</a>//! macro definition into a list of patterns and templates. |
| <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::fmt; |
| <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::sym; |
| <a href=#8 id=8 data-nosnippet>8</a> |
| <a href=#9 id=9 data-nosnippet>9</a><span class="kw">use crate</span>::{Ident, Leaf, MAX_GLUED_PUNCT_LEN, Punct, Spacing, Subtree, TokenTree, TokenTreesView}; |
| <a href=#10 id=10 data-nosnippet>10</a> |
| <a href=#11 id=11 data-nosnippet>11</a><span class="attr">#[derive(Clone)] |
| <a href=#12 id=12 data-nosnippet>12</a></span><span class="kw">pub struct </span>TtIter<<span class="lifetime">'a</span>, S> { |
| <a href=#13 id=13 data-nosnippet>13</a> inner: std::slice::Iter<<span class="lifetime">'a</span>, TokenTree<S>>, |
| <a href=#14 id=14 data-nosnippet>14</a>} |
| <a href=#15 id=15 data-nosnippet>15</a> |
| <a href=#16 id=16 data-nosnippet>16</a><span class="kw">impl</span><S: Copy + fmt::Debug> fmt::Debug <span class="kw">for </span>TtIter<<span class="lifetime">'_</span>, S> { |
| <a href=#17 id=17 data-nosnippet>17</a> <span class="kw">fn </span>fmt(<span class="kw-2">&</span><span class="self">self</span>, f: <span class="kw-2">&mut </span>fmt::Formatter<<span class="lifetime">'_</span>>) -> fmt::Result { |
| <a href=#18 id=18 data-nosnippet>18</a> f.debug_struct(<span class="string">"TtIter"</span>).field(<span class="string">"remaining"</span>, <span class="kw-2">&</span><span class="self">self</span>.remaining()).finish() |
| <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> |
| <a href=#22 id=22 data-nosnippet>22</a><span class="attr">#[derive(Clone, Copy)] |
| <a href=#23 id=23 data-nosnippet>23</a></span><span class="kw">pub struct </span>TtIterSavepoint<<span class="lifetime">'a</span>, S>(<span class="kw-2">&</span><span class="lifetime">'a </span>[TokenTree<S>]); |
| <a href=#24 id=24 data-nosnippet>24</a> |
| <a href=#25 id=25 data-nosnippet>25</a><span class="kw">impl</span><<span class="lifetime">'a</span>, S: Copy> TtIterSavepoint<<span class="lifetime">'a</span>, S> { |
| <a href=#26 id=26 data-nosnippet>26</a> <span class="kw">pub fn </span>remaining(<span class="self">self</span>) -> TokenTreesView<<span class="lifetime">'a</span>, S> { |
| <a href=#27 id=27 data-nosnippet>27</a> TokenTreesView::new(<span class="self">self</span>.<span class="number">0</span>) |
| <a href=#28 id=28 data-nosnippet>28</a> } |
| <a href=#29 id=29 data-nosnippet>29</a>} |
| <a href=#30 id=30 data-nosnippet>30</a> |
| <a href=#31 id=31 data-nosnippet>31</a><span class="kw">impl</span><<span class="lifetime">'a</span>, S: Copy> TtIter<<span class="lifetime">'a</span>, S> { |
| <a href=#32 id=32 data-nosnippet>32</a> <span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">fn </span>new(tt: <span class="kw-2">&</span><span class="lifetime">'a </span>[TokenTree<S>]) -> TtIter<<span class="lifetime">'a</span>, S> { |
| <a href=#33 id=33 data-nosnippet>33</a> TtIter { inner: tt.iter() } |
| <a href=#34 id=34 data-nosnippet>34</a> } |
| <a href=#35 id=35 data-nosnippet>35</a> |
| <a href=#36 id=36 data-nosnippet>36</a> <span class="kw">pub fn </span>expect_char(<span class="kw-2">&mut </span><span class="self">self</span>, char: char) -> <span class="prelude-ty">Result</span><(), ()> { |
| <a href=#37 id=37 data-nosnippet>37</a> <span class="kw">match </span><span class="self">self</span>.next() { |
| <a href=#38 id=38 data-nosnippet>38</a> <span class="prelude-val">Some</span>(TtElement::Leaf(<span class="kw-2">&</span>Leaf::Punct(Punct { char: c, .. }))) <span class="kw">if </span>c == char => <span class="prelude-val">Ok</span>(()), |
| <a href=#39 id=39 data-nosnippet>39</a> <span class="kw">_ </span>=> <span class="prelude-val">Err</span>(()), |
| <a href=#40 id=40 data-nosnippet>40</a> } |
| <a href=#41 id=41 data-nosnippet>41</a> } |
| <a href=#42 id=42 data-nosnippet>42</a> |
| <a href=#43 id=43 data-nosnippet>43</a> <span class="kw">pub fn </span>expect_any_char(<span class="kw-2">&mut </span><span class="self">self</span>, chars: <span class="kw-2">&</span>[char]) -> <span class="prelude-ty">Result</span><(), ()> { |
| <a href=#44 id=44 data-nosnippet>44</a> <span class="kw">match </span><span class="self">self</span>.next() { |
| <a href=#45 id=45 data-nosnippet>45</a> <span class="prelude-val">Some</span>(TtElement::Leaf(Leaf::Punct(Punct { char: c, .. }))) <span class="kw">if </span>chars.contains(c) => { |
| <a href=#46 id=46 data-nosnippet>46</a> <span class="prelude-val">Ok</span>(()) |
| <a href=#47 id=47 data-nosnippet>47</a> } |
| <a href=#48 id=48 data-nosnippet>48</a> <span class="kw">_ </span>=> <span class="prelude-val">Err</span>(()), |
| <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> |
| <a href=#52 id=52 data-nosnippet>52</a> <span class="kw">pub fn </span>expect_subtree(<span class="kw-2">&mut </span><span class="self">self</span>) -> <span class="prelude-ty">Result</span><(<span class="kw-2">&</span><span class="lifetime">'a </span>Subtree<S>, TtIter<<span class="lifetime">'a</span>, S>), ()> { |
| <a href=#53 id=53 data-nosnippet>53</a> <span class="kw">match </span><span class="self">self</span>.next() { |
| <a href=#54 id=54 data-nosnippet>54</a> <span class="prelude-val">Some</span>(TtElement::Subtree(subtree, iter)) => <span class="prelude-val">Ok</span>((subtree, iter)), |
| <a href=#55 id=55 data-nosnippet>55</a> <span class="kw">_ </span>=> <span class="prelude-val">Err</span>(()), |
| <a href=#56 id=56 data-nosnippet>56</a> } |
| <a href=#57 id=57 data-nosnippet>57</a> } |
| <a href=#58 id=58 data-nosnippet>58</a> |
| <a href=#59 id=59 data-nosnippet>59</a> <span class="kw">pub fn </span>expect_leaf(<span class="kw-2">&mut </span><span class="self">self</span>) -> <span class="prelude-ty">Result</span><<span class="kw-2">&</span><span class="lifetime">'a </span>Leaf<S>, ()> { |
| <a href=#60 id=60 data-nosnippet>60</a> <span class="kw">match </span><span class="self">self</span>.next() { |
| <a href=#61 id=61 data-nosnippet>61</a> <span class="prelude-val">Some</span>(TtElement::Leaf(it)) => <span class="prelude-val">Ok</span>(it), |
| <a href=#62 id=62 data-nosnippet>62</a> <span class="kw">_ </span>=> <span class="prelude-val">Err</span>(()), |
| <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="kw">pub fn </span>expect_dollar(<span class="kw-2">&mut </span><span class="self">self</span>) -> <span class="prelude-ty">Result</span><(), ()> { |
| <a href=#67 id=67 data-nosnippet>67</a> <span class="kw">match </span><span class="self">self</span>.expect_leaf()<span class="question-mark">? </span>{ |
| <a href=#68 id=68 data-nosnippet>68</a> Leaf::Punct(Punct { char: <span class="string">'$'</span>, .. }) => <span class="prelude-val">Ok</span>(()), |
| <a href=#69 id=69 data-nosnippet>69</a> <span class="kw">_ </span>=> <span class="prelude-val">Err</span>(()), |
| <a href=#70 id=70 data-nosnippet>70</a> } |
| <a href=#71 id=71 data-nosnippet>71</a> } |
| <a href=#72 id=72 data-nosnippet>72</a> |
| <a href=#73 id=73 data-nosnippet>73</a> <span class="kw">pub fn </span>expect_comma(<span class="kw-2">&mut </span><span class="self">self</span>) -> <span class="prelude-ty">Result</span><(), ()> { |
| <a href=#74 id=74 data-nosnippet>74</a> <span class="kw">match </span><span class="self">self</span>.expect_leaf()<span class="question-mark">? </span>{ |
| <a href=#75 id=75 data-nosnippet>75</a> Leaf::Punct(Punct { char: <span class="string">','</span>, .. }) => <span class="prelude-val">Ok</span>(()), |
| <a href=#76 id=76 data-nosnippet>76</a> <span class="kw">_ </span>=> <span class="prelude-val">Err</span>(()), |
| <a href=#77 id=77 data-nosnippet>77</a> } |
| <a href=#78 id=78 data-nosnippet>78</a> } |
| <a href=#79 id=79 data-nosnippet>79</a> |
| <a href=#80 id=80 data-nosnippet>80</a> <span class="kw">pub fn </span>expect_ident(<span class="kw-2">&mut </span><span class="self">self</span>) -> <span class="prelude-ty">Result</span><<span class="kw-2">&</span><span class="lifetime">'a </span>Ident<S>, ()> { |
| <a href=#81 id=81 data-nosnippet>81</a> <span class="kw">match </span><span class="self">self</span>.expect_leaf()<span class="question-mark">? </span>{ |
| <a href=#82 id=82 data-nosnippet>82</a> Leaf::Ident(it) <span class="kw">if </span>it.sym != sym::underscore => <span class="prelude-val">Ok</span>(it), |
| <a href=#83 id=83 data-nosnippet>83</a> <span class="kw">_ </span>=> <span class="prelude-val">Err</span>(()), |
| <a href=#84 id=84 data-nosnippet>84</a> } |
| <a href=#85 id=85 data-nosnippet>85</a> } |
| <a href=#86 id=86 data-nosnippet>86</a> |
| <a href=#87 id=87 data-nosnippet>87</a> <span class="kw">pub fn </span>expect_ident_or_underscore(<span class="kw-2">&mut </span><span class="self">self</span>) -> <span class="prelude-ty">Result</span><<span class="kw-2">&</span><span class="lifetime">'a </span>Ident<S>, ()> { |
| <a href=#88 id=88 data-nosnippet>88</a> <span class="kw">match </span><span class="self">self</span>.expect_leaf()<span class="question-mark">? </span>{ |
| <a href=#89 id=89 data-nosnippet>89</a> Leaf::Ident(it) => <span class="prelude-val">Ok</span>(it), |
| <a href=#90 id=90 data-nosnippet>90</a> <span class="kw">_ </span>=> <span class="prelude-val">Err</span>(()), |
| <a href=#91 id=91 data-nosnippet>91</a> } |
| <a href=#92 id=92 data-nosnippet>92</a> } |
| <a href=#93 id=93 data-nosnippet>93</a> |
| <a href=#94 id=94 data-nosnippet>94</a> <span class="kw">pub fn </span>expect_literal(<span class="kw-2">&mut </span><span class="self">self</span>) -> <span class="prelude-ty">Result</span><<span class="kw-2">&</span><span class="lifetime">'a </span>Leaf<S>, ()> { |
| <a href=#95 id=95 data-nosnippet>95</a> <span class="kw">let </span>it = <span class="self">self</span>.expect_leaf()<span class="question-mark">?</span>; |
| <a href=#96 id=96 data-nosnippet>96</a> <span class="kw">match </span>it { |
| <a href=#97 id=97 data-nosnippet>97</a> Leaf::Literal(<span class="kw">_</span>) => <span class="prelude-val">Ok</span>(it), |
| <a href=#98 id=98 data-nosnippet>98</a> Leaf::Ident(ident) <span class="kw">if </span>ident.sym == sym::true_ || ident.sym == sym::false_ => <span class="prelude-val">Ok</span>(it), |
| <a href=#99 id=99 data-nosnippet>99</a> <span class="kw">_ </span>=> <span class="prelude-val">Err</span>(()), |
| <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 class="kw">pub fn </span>expect_single_punct(<span class="kw-2">&mut </span><span class="self">self</span>) -> <span class="prelude-ty">Result</span><<span class="kw-2">&</span><span class="lifetime">'a </span>Punct<S>, ()> { |
| <a href=#104 id=104 data-nosnippet>104</a> <span class="kw">match </span><span class="self">self</span>.expect_leaf()<span class="question-mark">? </span>{ |
| <a href=#105 id=105 data-nosnippet>105</a> Leaf::Punct(it) => <span class="prelude-val">Ok</span>(it), |
| <a href=#106 id=106 data-nosnippet>106</a> <span class="kw">_ </span>=> <span class="prelude-val">Err</span>(()), |
| <a href=#107 id=107 data-nosnippet>107</a> } |
| <a href=#108 id=108 data-nosnippet>108</a> } |
| <a href=#109 id=109 data-nosnippet>109</a> |
| <a href=#110 id=110 data-nosnippet>110</a> <span class="doccomment">/// Returns consecutive `Punct`s that can be glued together. |
| <a href=#111 id=111 data-nosnippet>111</a> /// |
| <a href=#112 id=112 data-nosnippet>112</a> /// This method currently may return a single quotation, which is part of lifetime ident and |
| <a href=#113 id=113 data-nosnippet>113</a> /// conceptually not a punct in the context of mbe. Callers should handle this. |
| <a href=#114 id=114 data-nosnippet>114</a> </span><span class="kw">pub fn </span>expect_glued_punct(<span class="kw-2">&mut </span><span class="self">self</span>) -> <span class="prelude-ty">Result</span><ArrayVec<Punct<S>, MAX_GLUED_PUNCT_LEN>, ()> { |
| <a href=#115 id=115 data-nosnippet>115</a> <span class="kw">let </span>TtElement::Leaf(<span class="kw-2">&</span>Leaf::Punct(first)) = <span class="self">self</span>.next().ok_or(())<span class="question-mark">? </span><span class="kw">else </span>{ |
| <a href=#116 id=116 data-nosnippet>116</a> <span class="kw">return </span><span class="prelude-val">Err</span>(()); |
| <a href=#117 id=117 data-nosnippet>117</a> }; |
| <a href=#118 id=118 data-nosnippet>118</a> |
| <a href=#119 id=119 data-nosnippet>119</a> <span class="kw">let </span><span class="kw-2">mut </span>res = ArrayVec::new(); |
| <a href=#120 id=120 data-nosnippet>120</a> <span class="kw">if </span>first.spacing == Spacing::Alone { |
| <a href=#121 id=121 data-nosnippet>121</a> res.push(first); |
| <a href=#122 id=122 data-nosnippet>122</a> <span class="kw">return </span><span class="prelude-val">Ok</span>(res); |
| <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="kw">let </span>(second, third) = <span class="kw">match </span>(<span class="self">self</span>.peek_n(<span class="number">0</span>), <span class="self">self</span>.peek_n(<span class="number">1</span>)) { |
| <a href=#126 id=126 data-nosnippet>126</a> (<span class="prelude-val">Some</span>(TokenTree::Leaf(Leaf::Punct(p2))), <span class="prelude-val">Some</span>(TokenTree::Leaf(Leaf::Punct(p3)))) |
| <a href=#127 id=127 data-nosnippet>127</a> <span class="kw">if </span>p2.spacing == Spacing::Joint => |
| <a href=#128 id=128 data-nosnippet>128</a> { |
| <a href=#129 id=129 data-nosnippet>129</a> (p2, <span class="prelude-val">Some</span>(p3)) |
| <a href=#130 id=130 data-nosnippet>130</a> } |
| <a href=#131 id=131 data-nosnippet>131</a> (<span class="prelude-val">Some</span>(TokenTree::Leaf(Leaf::Punct(p2))), <span class="kw">_</span>) => (p2, <span class="prelude-val">None</span>), |
| <a href=#132 id=132 data-nosnippet>132</a> <span class="kw">_ </span>=> { |
| <a href=#133 id=133 data-nosnippet>133</a> res.push(first); |
| <a href=#134 id=134 data-nosnippet>134</a> <span class="kw">return </span><span class="prelude-val">Ok</span>(res); |
| <a href=#135 id=135 data-nosnippet>135</a> } |
| <a href=#136 id=136 data-nosnippet>136</a> }; |
| <a href=#137 id=137 data-nosnippet>137</a> |
| <a href=#138 id=138 data-nosnippet>138</a> <span class="kw">match </span>(first.char, second.char, third.map(|it| it.char)) { |
| <a href=#139 id=139 data-nosnippet>139</a> (<span class="string">'.'</span>, <span class="string">'.'</span>, <span class="prelude-val">Some</span>(<span class="string">'.' </span>| <span class="string">'='</span>)) | (<span class="string">'<'</span>, <span class="string">'<'</span>, <span class="prelude-val">Some</span>(<span class="string">'='</span>)) | (<span class="string">'>'</span>, <span class="string">'>'</span>, <span class="prelude-val">Some</span>(<span class="string">'='</span>)) => { |
| <a href=#140 id=140 data-nosnippet>140</a> <span class="kw">let _ </span>= <span class="self">self</span>.next().unwrap(); |
| <a href=#141 id=141 data-nosnippet>141</a> <span class="kw">let _ </span>= <span class="self">self</span>.next().unwrap(); |
| <a href=#142 id=142 data-nosnippet>142</a> res.push(first); |
| <a href=#143 id=143 data-nosnippet>143</a> res.push(<span class="kw-2">*</span>second); |
| <a href=#144 id=144 data-nosnippet>144</a> res.push(<span class="kw-2">*</span>third.unwrap()); |
| <a href=#145 id=145 data-nosnippet>145</a> } |
| <a href=#146 id=146 data-nosnippet>146</a> (<span class="string">'-' </span>| <span class="string">'!' </span>| <span class="string">'*' </span>| <span class="string">'/' </span>| <span class="string">'&' </span>| <span class="string">'%' </span>| <span class="string">'^' </span>| <span class="string">'+' </span>| <span class="string">'<' </span>| <span class="string">'=' </span>| <span class="string">'>' </span>| <span class="string">'|'</span>, <span class="string">'='</span>, <span class="kw">_</span>) |
| <a href=#147 id=147 data-nosnippet>147</a> | (<span class="string">'-' </span>| <span class="string">'=' </span>| <span class="string">'>'</span>, <span class="string">'>'</span>, <span class="kw">_</span>) |
| <a href=#148 id=148 data-nosnippet>148</a> | (<span class="string">'<'</span>, <span class="string">'-'</span>, <span class="kw">_</span>) |
| <a href=#149 id=149 data-nosnippet>149</a> | (<span class="string">':'</span>, <span class="string">':'</span>, <span class="kw">_</span>) |
| <a href=#150 id=150 data-nosnippet>150</a> | (<span class="string">'.'</span>, <span class="string">'.'</span>, <span class="kw">_</span>) |
| <a href=#151 id=151 data-nosnippet>151</a> | (<span class="string">'&'</span>, <span class="string">'&'</span>, <span class="kw">_</span>) |
| <a href=#152 id=152 data-nosnippet>152</a> | (<span class="string">'<'</span>, <span class="string">'<'</span>, <span class="kw">_</span>) |
| <a href=#153 id=153 data-nosnippet>153</a> | (<span class="string">'|'</span>, <span class="string">'|'</span>, <span class="kw">_</span>) => { |
| <a href=#154 id=154 data-nosnippet>154</a> <span class="kw">let _ </span>= <span class="self">self</span>.next().unwrap(); |
| <a href=#155 id=155 data-nosnippet>155</a> res.push(first); |
| <a href=#156 id=156 data-nosnippet>156</a> res.push(<span class="kw-2">*</span>second); |
| <a href=#157 id=157 data-nosnippet>157</a> } |
| <a href=#158 id=158 data-nosnippet>158</a> <span class="kw">_ </span>=> res.push(first), |
| <a href=#159 id=159 data-nosnippet>159</a> } |
| <a href=#160 id=160 data-nosnippet>160</a> <span class="prelude-val">Ok</span>(res) |
| <a href=#161 id=161 data-nosnippet>161</a> } |
| <a href=#162 id=162 data-nosnippet>162</a> |
| <a href=#163 id=163 data-nosnippet>163</a> <span class="doccomment">/// This method won't check for subtrees, so the nth token tree may not be the nth sibling of the current tree. |
| <a href=#164 id=164 data-nosnippet>164</a> </span><span class="kw">fn </span>peek_n(<span class="kw-2">&</span><span class="self">self</span>, n: usize) -> <span class="prelude-ty">Option</span><<span class="kw-2">&</span><span class="lifetime">'a </span>TokenTree<S>> { |
| <a href=#165 id=165 data-nosnippet>165</a> <span class="self">self</span>.inner.as_slice().get(n) |
| <a href=#166 id=166 data-nosnippet>166</a> } |
| <a href=#167 id=167 data-nosnippet>167</a> |
| <a href=#168 id=168 data-nosnippet>168</a> <span class="kw">pub fn </span>peek(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="prelude-ty">Option</span><TtElement<<span class="lifetime">'a</span>, S>> { |
| <a href=#169 id=169 data-nosnippet>169</a> <span class="kw">match </span><span class="self">self</span>.inner.as_slice().first()<span class="question-mark">? </span>{ |
| <a href=#170 id=170 data-nosnippet>170</a> TokenTree::Leaf(leaf) => <span class="prelude-val">Some</span>(TtElement::Leaf(leaf)), |
| <a href=#171 id=171 data-nosnippet>171</a> TokenTree::Subtree(subtree) => { |
| <a href=#172 id=172 data-nosnippet>172</a> <span class="kw">let </span>nested_iter = |
| <a href=#173 id=173 data-nosnippet>173</a> TtIter { inner: <span class="self">self</span>.inner.as_slice()[<span class="number">1</span>..][..subtree.usize_len()].iter() }; |
| <a href=#174 id=174 data-nosnippet>174</a> <span class="prelude-val">Some</span>(TtElement::Subtree(subtree, nested_iter)) |
| <a href=#175 id=175 data-nosnippet>175</a> } |
| <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> <span class="doccomment">/// Equivalent to `peek().is_none()`, but a bit faster. |
| <a href=#180 id=180 data-nosnippet>180</a> </span><span class="kw">pub fn </span>is_empty(<span class="kw-2">&</span><span class="self">self</span>) -> bool { |
| <a href=#181 id=181 data-nosnippet>181</a> <span class="self">self</span>.inner.len() == <span class="number">0 |
| <a href=#182 id=182 data-nosnippet>182</a> </span>} |
| <a href=#183 id=183 data-nosnippet>183</a> |
| <a href=#184 id=184 data-nosnippet>184</a> <span class="kw">pub fn </span>next_span(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="prelude-ty">Option</span><S> { |
| <a href=#185 id=185 data-nosnippet>185</a> <span class="prelude-val">Some</span>(<span class="self">self</span>.inner.as_slice().first()<span class="question-mark">?</span>.first_span()) |
| <a href=#186 id=186 data-nosnippet>186</a> } |
| <a href=#187 id=187 data-nosnippet>187</a> |
| <a href=#188 id=188 data-nosnippet>188</a> <span class="kw">pub fn </span>remaining(<span class="kw-2">&</span><span class="self">self</span>) -> TokenTreesView<<span class="lifetime">'a</span>, S> { |
| <a href=#189 id=189 data-nosnippet>189</a> TokenTreesView::new(<span class="self">self</span>.inner.as_slice()) |
| <a href=#190 id=190 data-nosnippet>190</a> } |
| <a href=#191 id=191 data-nosnippet>191</a> |
| <a href=#192 id=192 data-nosnippet>192</a> <span class="doccomment">/// **Warning**: This advances `skip` **flat** token trees, subtrees account for children+1! |
| <a href=#193 id=193 data-nosnippet>193</a> </span><span class="kw">pub fn </span>flat_advance(<span class="kw-2">&mut </span><span class="self">self</span>, skip: usize) { |
| <a href=#194 id=194 data-nosnippet>194</a> <span class="self">self</span>.inner = <span class="self">self</span>.inner.as_slice()[skip..].iter(); |
| <a href=#195 id=195 data-nosnippet>195</a> } |
| <a href=#196 id=196 data-nosnippet>196</a> |
| <a href=#197 id=197 data-nosnippet>197</a> <span class="kw">pub fn </span>savepoint(<span class="kw-2">&</span><span class="self">self</span>) -> TtIterSavepoint<<span class="lifetime">'a</span>, S> { |
| <a href=#198 id=198 data-nosnippet>198</a> TtIterSavepoint(<span class="self">self</span>.inner.as_slice()) |
| <a href=#199 id=199 data-nosnippet>199</a> } |
| <a href=#200 id=200 data-nosnippet>200</a> |
| <a href=#201 id=201 data-nosnippet>201</a> <span class="kw">pub fn </span>from_savepoint(<span class="kw-2">&</span><span class="self">self</span>, savepoint: TtIterSavepoint<<span class="lifetime">'a</span>, S>) -> TokenTreesView<<span class="lifetime">'a</span>, S> { |
| <a href=#202 id=202 data-nosnippet>202</a> <span class="kw">let </span>len = (<span class="self">self</span>.inner.as_slice().as_ptr() <span class="kw">as </span>usize - savepoint.<span class="number">0</span>.as_ptr() <span class="kw">as </span>usize) |
| <a href=#203 id=203 data-nosnippet>203</a> / size_of::<TokenTree<S>>(); |
| <a href=#204 id=204 data-nosnippet>204</a> TokenTreesView::new(<span class="kw-2">&</span>savepoint.<span class="number">0</span>[..len]) |
| <a href=#205 id=205 data-nosnippet>205</a> } |
| <a href=#206 id=206 data-nosnippet>206</a> |
| <a href=#207 id=207 data-nosnippet>207</a> <span class="kw">pub fn </span>next_as_view(<span class="kw-2">&mut </span><span class="self">self</span>) -> <span class="prelude-ty">Option</span><TokenTreesView<<span class="lifetime">'a</span>, S>> { |
| <a href=#208 id=208 data-nosnippet>208</a> <span class="kw">let </span>savepoint = <span class="self">self</span>.savepoint(); |
| <a href=#209 id=209 data-nosnippet>209</a> <span class="self">self</span>.next()<span class="question-mark">?</span>; |
| <a href=#210 id=210 data-nosnippet>210</a> <span class="prelude-val">Some</span>(<span class="self">self</span>.from_savepoint(savepoint)) |
| <a href=#211 id=211 data-nosnippet>211</a> } |
| <a href=#212 id=212 data-nosnippet>212</a>} |
| <a href=#213 id=213 data-nosnippet>213</a> |
| <a href=#214 id=214 data-nosnippet>214</a><span class="attr">#[derive(Clone)] |
| <a href=#215 id=215 data-nosnippet>215</a></span><span class="kw">pub enum </span>TtElement<<span class="lifetime">'a</span>, S> { |
| <a href=#216 id=216 data-nosnippet>216</a> Leaf(<span class="kw-2">&</span><span class="lifetime">'a </span>Leaf<S>), |
| <a href=#217 id=217 data-nosnippet>217</a> Subtree(<span class="kw-2">&</span><span class="lifetime">'a </span>Subtree<S>, TtIter<<span class="lifetime">'a</span>, S>), |
| <a href=#218 id=218 data-nosnippet>218</a>} |
| <a href=#219 id=219 data-nosnippet>219</a> |
| <a href=#220 id=220 data-nosnippet>220</a><span class="kw">impl</span><S: Copy + fmt::Debug> fmt::Debug <span class="kw">for </span>TtElement<<span class="lifetime">'_</span>, S> { |
| <a href=#221 id=221 data-nosnippet>221</a> <span class="kw">fn </span>fmt(<span class="kw-2">&</span><span class="self">self</span>, f: <span class="kw-2">&mut </span>fmt::Formatter<<span class="lifetime">'_</span>>) -> fmt::Result { |
| <a href=#222 id=222 data-nosnippet>222</a> <span class="kw">match </span><span class="self">self </span>{ |
| <a href=#223 id=223 data-nosnippet>223</a> <span class="self">Self</span>::Leaf(leaf) => f.debug_tuple(<span class="string">"Leaf"</span>).field(leaf).finish(), |
| <a href=#224 id=224 data-nosnippet>224</a> <span class="self">Self</span>::Subtree(subtree, inner) => { |
| <a href=#225 id=225 data-nosnippet>225</a> f.debug_tuple(<span class="string">"Subtree"</span>).field(subtree).field(inner).finish() |
| <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>} |
| <a href=#230 id=230 data-nosnippet>230</a> |
| <a href=#231 id=231 data-nosnippet>231</a><span class="kw">impl</span><S: Copy> TtElement<<span class="lifetime">'_</span>, S> { |
| <a href=#232 id=232 data-nosnippet>232</a> <span class="attr">#[inline] |
| <a href=#233 id=233 data-nosnippet>233</a> </span><span class="kw">pub fn </span>first_span(<span class="kw-2">&</span><span class="self">self</span>) -> S { |
| <a href=#234 id=234 data-nosnippet>234</a> <span class="kw">match </span><span class="self">self </span>{ |
| <a href=#235 id=235 data-nosnippet>235</a> TtElement::Leaf(it) => <span class="kw-2">*</span>it.span(), |
| <a href=#236 id=236 data-nosnippet>236</a> TtElement::Subtree(it, <span class="kw">_</span>) => it.delimiter.open, |
| <a href=#237 id=237 data-nosnippet>237</a> } |
| <a href=#238 id=238 data-nosnippet>238</a> } |
| <a href=#239 id=239 data-nosnippet>239</a>} |
| <a href=#240 id=240 data-nosnippet>240</a> |
| <a href=#241 id=241 data-nosnippet>241</a><span class="kw">impl</span><<span class="lifetime">'a</span>, S> Iterator <span class="kw">for </span>TtIter<<span class="lifetime">'a</span>, S> { |
| <a href=#242 id=242 data-nosnippet>242</a> <span class="kw">type </span>Item = TtElement<<span class="lifetime">'a</span>, S>; |
| <a href=#243 id=243 data-nosnippet>243</a> <span class="kw">fn </span>next(<span class="kw-2">&mut </span><span class="self">self</span>) -> <span class="prelude-ty">Option</span><<span class="self">Self</span>::Item> { |
| <a href=#244 id=244 data-nosnippet>244</a> <span class="kw">match </span><span class="self">self</span>.inner.next()<span class="question-mark">? </span>{ |
| <a href=#245 id=245 data-nosnippet>245</a> TokenTree::Leaf(leaf) => <span class="prelude-val">Some</span>(TtElement::Leaf(leaf)), |
| <a href=#246 id=246 data-nosnippet>246</a> TokenTree::Subtree(subtree) => { |
| <a href=#247 id=247 data-nosnippet>247</a> <span class="kw">let </span>nested_iter = |
| <a href=#248 id=248 data-nosnippet>248</a> TtIter { inner: <span class="self">self</span>.inner.as_slice()[..subtree.usize_len()].iter() }; |
| <a href=#249 id=249 data-nosnippet>249</a> <span class="self">self</span>.inner = <span class="self">self</span>.inner.as_slice()[subtree.usize_len()..].iter(); |
| <a href=#250 id=250 data-nosnippet>250</a> <span class="prelude-val">Some</span>(TtElement::Subtree(subtree, nested_iter)) |
| <a href=#251 id=251 data-nosnippet>251</a> } |
| <a href=#252 id=252 data-nosnippet>252</a> } |
| <a href=#253 id=253 data-nosnippet>253</a> } |
| <a href=#254 id=254 data-nosnippet>254</a>}</code></pre></div></section></main></body></html> |
