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diff --git a/guides/rainbow_bracket_queries.html b/guides/rainbow_bracket_queries.html new file mode 100644 index 00000000..98f11d99 --- /dev/null +++ b/guides/rainbow_bracket_queries.html @@ -0,0 +1,323 @@ +<!DOCTYPE HTML> +<html lang="en" class="colibri" dir="ltr"> + <head> + <!-- Book generated using mdBook --> + <meta charset="UTF-8"> + <title>Adding rainbow bracket queries</title> + + + <!-- Custom HTML head --> + + <meta name="description" content=""> + <meta name="viewport" content="width=device-width, initial-scale=1"> + <meta name="theme-color" content="#ffffff"> + + <link rel="icon" href="../favicon.svg"> + <link rel="shortcut icon" href="../favicon.png"> + <link rel="stylesheet" href="../css/variables.css"> + <link rel="stylesheet" href="../css/general.css"> + <link rel="stylesheet" href="../css/chrome.css"> + <link rel="stylesheet" href="../css/print.css" media="print"> + + <!-- Fonts --> + <link rel="stylesheet" href="../FontAwesome/css/font-awesome.css"> + <link rel="stylesheet" href="../fonts/fonts.css"> + + <!-- Highlight.js Stylesheets --> + <link rel="stylesheet" href="../highlight.css"> + <link rel="stylesheet" href="../tomorrow-night.css"> + <link rel="stylesheet" href="../ayu-highlight.css"> + + <!-- Custom theme stylesheets --> + <link rel="stylesheet" href="../custom.css"> + + </head> + <body class="sidebar-visible no-js"> + <div id="body-container"> + <!-- Provide site root to javascript --> + <script> + var path_to_root = "../"; + var default_theme = window.matchMedia("(prefers-color-scheme: dark)").matches ? 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(Shortkey: s)" aria-label="Toggle Searchbar" aria-expanded="false" aria-keyshortcuts="S" aria-controls="searchbar"> + <i class="fa fa-search"></i> + </button> + </div> + + <h1 class="menu-title"></h1> + + <div class="right-buttons"> + <a href="../print.html" title="Print this book" aria-label="Print this book"> + <i id="print-button" class="fa fa-print"></i> + </a> + <a href="https://github.com/helix-editor/helix" title="Git repository" aria-label="Git repository"> + <i id="git-repository-button" class="fa fa-github"></i> + </a> + <a href="https://github.com/helix-editor/helix/edit/master/book/src/guides/rainbow_bracket_queries.md" title="Suggest an edit" aria-label="Suggest an edit"> + <i id="git-edit-button" class="fa fa-edit"></i> + </a> + + </div> + </div> + + <div id="search-wrapper" class="hidden"> + <form id="searchbar-outer" class="searchbar-outer"> + <input type="search" id="searchbar" name="searchbar" placeholder="Search this book ..." aria-controls="searchresults-outer" aria-describedby="searchresults-header"> + </form> + <div id="searchresults-outer" class="searchresults-outer hidden"> + <div id="searchresults-header" class="searchresults-header"></div> + <ul id="searchresults"> + </ul> + </div> + </div> + + <!-- Apply ARIA attributes after the sidebar and the sidebar toggle button are added to the DOM --> + <script> + document.getElementById('sidebar-toggle').setAttribute('aria-expanded', sidebar === 'visible'); + document.getElementById('sidebar').setAttribute('aria-hidden', sidebar !== 'visible'); + Array.from(document.querySelectorAll('#sidebar a')).forEach(function(link) { + link.setAttribute('tabIndex', sidebar === 'visible' ? 0 : -1); + }); + </script> + + <div id="content" class="content"> + <main> + <h1 id="adding-rainbow-bracket-queries"><a class="header" href="#adding-rainbow-bracket-queries">Adding Rainbow Bracket Queries</a></h1> +<p>Helix uses <code>rainbows.scm</code> tree-sitter query files to provide rainbow bracket +functionality.</p> +<p>Tree-sitter queries are documented in the tree-sitter online documentation. +If you're writing queries for the first time, be sure to check out the section +on <a href="https://tree-sitter.github.io/tree-sitter/syntax-highlighting#highlights">syntax highlighting queries</a> and on <a href="https://tree-sitter.github.io/tree-sitter/using-parsers#pattern-matching-with-queries">query syntax</a>.</p> +<p>Rainbow queries have two captures: <code>@rainbow.scope</code> and <code>@rainbow.bracket</code>. +<code>@rainbow.scope</code> should capture any node that increases the nesting level +while <code>@rainbow.bracket</code> should capture any bracket nodes. Put another way: +<code>@rainbow.scope</code> switches to the next rainbow color for all nodes in the tree +under it while <code>@rainbow.bracket</code> paints captured nodes with the current +rainbow color.</p> +<p>For an example, let's add rainbow queries for the tree-sitter query (TSQ) +language itself. These queries will go into a +<code>runtime/queries/tsq/rainbows.scm</code> file in the repository root.</p> +<p>First we'll add the <code>@rainbow.bracket</code> captures. TSQ only has parentheses and +square brackets:</p> +<pre><code class="language-tsq">["(" ")" "[" "]"] @rainbow.bracket +</code></pre> +<p>The ordering of the nodes within the alternation (square brackets) is not +taken into consideration.</p> +<blockquote> +<p>Note: Why are these nodes quoted? Most syntax highlights capture text +surrounded by parentheses. These are <em>named nodes</em> and correspond to the +names of rules in the grammar. Brackets are usually written in tree-sitter +grammars as literal strings, for example:</p> +<pre><code class="language-js">{ + // ... + arguments: seq("(", repeat($.argument), ")"), + // ... +} +</code></pre> +<p>Nodes written as literal strings in tree-sitter grammars may be captured +in queries with those same literal strings.</p> +</blockquote> +<p>Then we'll add <code>@rainbow.scope</code> captures. The easiest way to do this is to +view the <code>grammar.js</code> file in the tree-sitter grammar's repository. For TSQ, +that file is <a href="https://github.com/the-mikedavis/tree-sitter-tsq/blob/48b5e9f82ae0a4727201626f33a17f69f8e0ff86/grammar.js">here</a>. As we scroll down the <code>grammar.js</code>, we +see that the <code>(alternation)</code>, (L36) <code>(group)</code> (L57), <code>(named_node)</code> (L59), +<code>(predicate)</code> (L87) and <code>(wildcard_node)</code> (L97) nodes all contain literal +parentheses or square brackets in their definitions. These nodes are all +direct parents of brackets and happen to also be the nodes we want to change +to the next rainbow color, so we capture them as <code>@rainbow.scope</code>.</p> +<pre><code class="language-tsq">[ + (group) + (named_node) + (wildcard_node) + (predicate) + (alternation) +] @rainbow.scope +</code></pre> +<p>This strategy works as a rule of thumb for most programming and configuration +languages. Markup languages can be trickier and may take additional +experimentation to find the correct nodes to use for scopes and brackets.</p> +<p>The <code>:tree-sitter-subtree</code> command shows the syntax tree under the primary +selection in S-expression format and can be a useful tool for determining how +to write a query.</p> +<h3 id="properties"><a class="header" href="#properties">Properties</a></h3> +<p>The <code>rainbow.include-children</code> property may be applied to <code>@rainbow.scope</code> +captures. By default, all <code>@rainbow.bracket</code> captures must be direct descendant +of a node captured with <code>@rainbow.scope</code> in a syntax tree in order to be +highlighted. The <code>rainbow.include-children</code> property disables that check and +allows <code>@rainbow.bracket</code> captures to be highlighted if they are direct or +indirect descendants of some node captured with <code>@rainbow.scope</code>.</p> +<p>For example, this property is used in the HTML rainbow queries.</p> +<p>For a document like <code><a>link</a></code>, the syntax tree is:</p> +<pre><code class="language-tsq">(element ; <a>link</a> + (start_tag ; <a> + (tag_name)) ; a + (text) ; link + (end_tag ; </a> + (tag_name))) ; a +</code></pre> +<p>If we want to highlight the <code><</code>, <code>></code> and <code></</code> nodes with rainbow colors, we +capture them as <code>@rainbow.bracket</code>:</p> +<pre><code class="language-tsq">["<" ">" "</"] @rainbow.bracket +</code></pre> +<p>And we capture <code>(element)</code> as <code>@rainbow.scope</code> because <code>(element)</code> nodes nest +within each other: they increment the nesting level and switch to the next +color in the rainbow.</p> +<pre><code class="language-tsq">(element) @rainbow.scope +</code></pre> +<p>But this combination of <code>@rainbow.scope</code> and <code>@rainbow.bracket</code> will not +highlight any nodes. <code><</code>, <code>></code> and <code></</code> are children of the <code>(start_tag)</code> and +<code>(end_tag)</code> nodes. We can't capture <code>(start_tag)</code> and <code>(end_tag)</code> as +<code>@rainbow.scope</code> because they don't nest other elements. We can fix this case +by removing the requirement that <code><</code>, <code>></code> and <code></</code> are direct descendants of +<code>(element)</code> using the <code>rainbow.include-children</code> property.</p> +<pre><code class="language-tsq">((element) @rainbow.scope + (#set! rainbow.include-children)) +</code></pre> +<p>With this property set, <code><</code>, <code>></code>, and <code></</code> will highlight with rainbow colors +even though they aren't direct descendents of the <code>(element)</code> node.</p> +<p><code>rainbow.include-children</code> is not necessary for the vast majority of programming +languages. It is only necessary when the node that increments the nesting level +(changes rainbow color) is not the direct parent of the bracket node.</p> + + </main> + + <nav class="nav-wrapper" aria-label="Page navigation"> + <!-- Mobile navigation buttons --> + <a rel="prev" href="../guides/injection.html" class="mobile-nav-chapters previous" title="Previous chapter" aria-label="Previous chapter" aria-keyshortcuts="Left"> + <i class="fa fa-angle-left"></i> + </a> + + + <div style="clear: both"></div> + </nav> + </div> + </div> + + <nav class="nav-wide-wrapper" aria-label="Page navigation"> + <a rel="prev" href="../guides/injection.html" class="nav-chapters previous" title="Previous chapter" aria-label="Previous chapter" aria-keyshortcuts="Left"> + <i class="fa fa-angle-left"></i> + </a> + + </nav> + + </div> + + + + + <script> + window.playground_copyable = true; + </script> + + + <script src="../elasticlunr.min.js"></script> + <script src="../mark.min.js"></script> + <script src="../searcher.js"></script> + + <script src="../clipboard.min.js"></script> + <script src="../highlight.js"></script> + <script src="../book.js"></script> + + <!-- Custom JS scripts --> + + + </div> + </body> +</html> |