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} a[href^="https:"] { text-decoration: underline; } code > span.kw { color: #555; font-weight: bold; } code > span.dt { color: #902000; } code > span.dv { color: #40a070; } code > span.bn { color: #d14; } code > span.fl { color: #d14; } code > span.ch { color: #d14; } code > span.st { color: #d14; } code > span.co { color: #888888; font-style: italic; } code > span.ot { color: #007020; } code > span.al { color: #ff0000; font-weight: bold; } code > span.fu { color: #900; font-weight: bold; } code > span.er { color: #a61717; background-color: #e3d2d2; } </style> </head> <body> <h1 class="title toc-ignore">Transformers</h1> <p>Transformers allow you to apply functions to the glue input and output, before and after evaluation. This allows you to write things like <code>glue_sql()</code>, which automatically quotes variables for you or add a syntax for automatically collapsing outputs.</p> <p>The transformer functions simply take two arguments <code>text</code> and <code>envir</code>, where <code>text</code> is the unparsed string inside the glue block and <code>envir</code> is the execution environment. Most transformers will then call <code>eval(parse(text = text, keep.source = FALSE), envir)</code> which parses and evaluates the code.</p> <p>You can then supply the transformer function to glue with the <code>.transformer</code> argument. In this way users can manipulate the text before parsing and change the output after evaluation.</p> <p>It is often useful to write a <code>glue()</code> wrapper function which supplies a <code>.transformer</code> to <code>glue()</code> or <code>glue_data()</code> and potentially has additional arguments. One important consideration when doing this is to include <code>.envir = parent.frame()</code> in the wrapper to ensure the evaluation environment is correct.</p> <p>Some example implementations of potentially useful transformers follow. The aim right now is not to include most of these custom functions within the <code>glue</code> package. Rather, users are encouraged to create custom functions using transformers to fit their individual needs.</p> <div class="sourceCode" id="cb1"><pre class="sourceCode r"><code class="sourceCode r"><span id="cb1-1"><a href="#cb1-1" aria-hidden="true" tabindex="-1"></a><span class="fu">library</span>(glue)</span></code></pre></div> <div id="collapse-transformer" class="section level3"> <h3>collapse transformer</h3> <p>A transformer which automatically collapses any glue block ending with <code>*</code>.</p> <div class="sourceCode" id="cb2"><pre class="sourceCode r"><code class="sourceCode r"><span id="cb2-1"><a href="#cb2-1" aria-hidden="true" tabindex="-1"></a>collapse_transformer <span class="ot"><-</span> <span class="cf">function</span>(<span class="at">regex =</span> <span class="st">"[*]$"</span>, ...) {</span> <span id="cb2-2"><a href="#cb2-2" aria-hidden="true" tabindex="-1"></a> <span class="cf">function</span>(text, envir) {</span> <span id="cb2-3"><a href="#cb2-3" aria-hidden="true" tabindex="-1"></a> collapse <span class="ot"><-</span> <span class="fu">grepl</span>(regex, text)</span> <span id="cb2-4"><a href="#cb2-4" aria-hidden="true" tabindex="-1"></a> <span class="cf">if</span> (collapse) {</span> <span id="cb2-5"><a href="#cb2-5" aria-hidden="true" tabindex="-1"></a> text <span class="ot"><-</span> <span class="fu">sub</span>(regex, <span class="st">""</span>, text)</span> <span id="cb2-6"><a href="#cb2-6" aria-hidden="true" tabindex="-1"></a> }</span> <span id="cb2-7"><a href="#cb2-7" aria-hidden="true" tabindex="-1"></a> res <span class="ot"><-</span> <span class="fu">identity_transformer</span>(text, envir)</span> <span id="cb2-8"><a href="#cb2-8" aria-hidden="true" tabindex="-1"></a> <span class="cf">if</span> (collapse) {</span> <span id="cb2-9"><a href="#cb2-9" aria-hidden="true" tabindex="-1"></a> <span class="fu">glue_collapse</span>(res, ...) </span> <span id="cb2-10"><a href="#cb2-10" aria-hidden="true" tabindex="-1"></a> } <span class="cf">else</span> {</span> <span id="cb2-11"><a href="#cb2-11" aria-hidden="true" tabindex="-1"></a> res</span> <span id="cb2-12"><a href="#cb2-12" aria-hidden="true" tabindex="-1"></a> }</span> <span id="cb2-13"><a href="#cb2-13" aria-hidden="true" tabindex="-1"></a> }</span> <span id="cb2-14"><a href="#cb2-14" aria-hidden="true" tabindex="-1"></a>}</span> <span id="cb2-15"><a href="#cb2-15" aria-hidden="true" tabindex="-1"></a></span> <span id="cb2-16"><a href="#cb2-16" aria-hidden="true" tabindex="-1"></a><span class="fu">glue</span>(<span class="st">"{1:5*}</span><span class="sc">\n</span><span class="st">{letters[1:5]*}"</span>, <span class="at">.transformer =</span> <span class="fu">collapse_transformer</span>(<span class="at">sep =</span> <span class="st">", "</span>))</span> <span id="cb2-17"><a href="#cb2-17" aria-hidden="true" tabindex="-1"></a><span class="co">#> 1, 2, 3, 4, 5</span></span> <span id="cb2-18"><a href="#cb2-18" aria-hidden="true" tabindex="-1"></a><span class="co">#> a, b, c, d, e</span></span> <span id="cb2-19"><a href="#cb2-19" aria-hidden="true" tabindex="-1"></a></span> <span id="cb2-20"><a href="#cb2-20" aria-hidden="true" tabindex="-1"></a><span class="fu">glue</span>(<span class="st">"{1:5*}</span><span class="sc">\n</span><span class="st">{letters[1:5]*}"</span>, <span class="at">.transformer =</span> <span class="fu">collapse_transformer</span>(<span class="at">sep =</span> <span class="st">", "</span>, <span class="at">last =</span> <span class="st">" and "</span>))</span> <span id="cb2-21"><a href="#cb2-21" aria-hidden="true" tabindex="-1"></a><span class="co">#> 1, 2, 3, 4 and 5</span></span> <span id="cb2-22"><a href="#cb2-22" aria-hidden="true" tabindex="-1"></a><span class="co">#> a, b, c, d and e</span></span> <span id="cb2-23"><a href="#cb2-23" aria-hidden="true" tabindex="-1"></a></span> <span id="cb2-24"><a href="#cb2-24" aria-hidden="true" tabindex="-1"></a>x <span class="ot"><-</span> <span class="fu">c</span>(<span class="st">"one"</span>, <span class="st">"two"</span>)</span> <span id="cb2-25"><a href="#cb2-25" aria-hidden="true" tabindex="-1"></a><span class="fu">glue</span>(<span class="st">"{x}: {1:5*}"</span>, <span class="at">.transformer =</span> <span class="fu">collapse_transformer</span>(<span class="at">sep =</span> <span class="st">", "</span>))</span> <span id="cb2-26"><a href="#cb2-26" aria-hidden="true" tabindex="-1"></a><span class="co">#> one: 1, 2, 3, 4, 5</span></span> <span id="cb2-27"><a href="#cb2-27" aria-hidden="true" tabindex="-1"></a><span class="co">#> two: 1, 2, 3, 4, 5</span></span></code></pre></div> </div> <div id="shell-quoting-transformer" class="section level3"> <h3>Shell quoting transformer</h3> <p>A transformer which automatically quotes variables for use in shell commands, e.g. via <code>system()</code> or <code>system2()</code>.</p> <div class="sourceCode" id="cb3"><pre class="sourceCode r"><code class="sourceCode r"><span id="cb3-1"><a href="#cb3-1" aria-hidden="true" tabindex="-1"></a>shell_transformer <span class="ot"><-</span> <span class="cf">function</span>(<span class="at">type =</span> <span class="fu">c</span>(<span class="st">"sh"</span>, <span class="st">"csh"</span>, <span class="st">"cmd"</span>, <span class="st">"cmd2"</span>)) {</span> <span id="cb3-2"><a href="#cb3-2" aria-hidden="true" tabindex="-1"></a> type <span class="ot"><-</span> <span class="fu">match.arg</span>(type)</span> <span id="cb3-3"><a href="#cb3-3" aria-hidden="true" tabindex="-1"></a> <span class="cf">function</span>(text, envir) {</span> <span id="cb3-4"><a href="#cb3-4" aria-hidden="true" tabindex="-1"></a> res <span class="ot"><-</span> <span class="fu">eval</span>(<span class="fu">parse</span>(<span class="at">text =</span> text, <span class="at">keep.source =</span> <span class="cn">FALSE</span>), envir)</span> <span id="cb3-5"><a href="#cb3-5" aria-hidden="true" tabindex="-1"></a> <span class="fu">shQuote</span>(res)</span> <span id="cb3-6"><a href="#cb3-6" aria-hidden="true" tabindex="-1"></a> }</span> <span id="cb3-7"><a href="#cb3-7" aria-hidden="true" tabindex="-1"></a>}</span> <span id="cb3-8"><a href="#cb3-8" aria-hidden="true" tabindex="-1"></a></span> <span id="cb3-9"><a href="#cb3-9" aria-hidden="true" tabindex="-1"></a>glue_sh <span class="ot"><-</span> <span class="cf">function</span>(..., <span class="at">.envir =</span> <span class="fu">parent.frame</span>(), <span class="at">.type =</span> <span class="fu">c</span>(<span class="st">"sh"</span>, <span class="st">"csh"</span>, <span class="st">"cmd"</span>, <span class="st">"cmd2"</span>)) {</span> <span id="cb3-10"><a href="#cb3-10" aria-hidden="true" tabindex="-1"></a> .type <span class="ot"><-</span> <span class="fu">match.arg</span>(.type)</span> <span id="cb3-11"><a href="#cb3-11" aria-hidden="true" tabindex="-1"></a> <span class="fu">glue</span>(..., <span class="at">.envir =</span> .envir, <span class="at">.transformer =</span> <span class="fu">shell_transformer</span>(.type))</span> <span id="cb3-12"><a href="#cb3-12" aria-hidden="true" tabindex="-1"></a></span> <span id="cb3-13"><a href="#cb3-13" aria-hidden="true" tabindex="-1"></a>}</span> <span id="cb3-14"><a href="#cb3-14" aria-hidden="true" tabindex="-1"></a></span> <span id="cb3-15"><a href="#cb3-15" aria-hidden="true" tabindex="-1"></a>filename <span class="ot"><-</span> <span class="st">"test"</span></span> <span id="cb3-16"><a href="#cb3-16" aria-hidden="true" tabindex="-1"></a><span class="fu">writeLines</span>(<span class="at">con =</span> filename, <span class="st">"hello!"</span>)</span> <span id="cb3-17"><a href="#cb3-17" aria-hidden="true" tabindex="-1"></a></span> <span id="cb3-18"><a href="#cb3-18" aria-hidden="true" tabindex="-1"></a>command <span class="ot"><-</span> <span class="fu">glue_sh</span>(<span class="st">"cat {filename}"</span>)</span> <span id="cb3-19"><a href="#cb3-19" aria-hidden="true" tabindex="-1"></a>command</span> <span id="cb3-20"><a href="#cb3-20" aria-hidden="true" tabindex="-1"></a><span class="co">#> cat 'test'</span></span> <span id="cb3-21"><a href="#cb3-21" aria-hidden="true" tabindex="-1"></a><span class="fu">system</span>(command)</span></code></pre></div> </div> <div id="emoji-transformer" class="section level3"> <h3>emoji transformer</h3> <p>A transformer which converts the text to the equivalent emoji.</p> <div class="sourceCode" id="cb4"><pre class="sourceCode r"><code class="sourceCode r"><span id="cb4-1"><a href="#cb4-1" aria-hidden="true" tabindex="-1"></a>emoji_transformer <span class="ot"><-</span> <span class="cf">function</span>(text, envir) {</span> <span id="cb4-2"><a href="#cb4-2" aria-hidden="true" tabindex="-1"></a> <span class="cf">if</span> (<span class="fu">grepl</span>(<span class="st">"[*]$"</span>, text)) {</span> <span id="cb4-3"><a href="#cb4-3" aria-hidden="true" tabindex="-1"></a> text <span class="ot"><-</span> <span class="fu">sub</span>(<span class="st">"[*]$"</span>, <span class="st">""</span>, text)</span> <span id="cb4-4"><a href="#cb4-4" aria-hidden="true" tabindex="-1"></a> <span class="fu">glue_collapse</span>(<span class="fu">ji_find</span>(text)<span class="sc">$</span>emoji)</span> <span id="cb4-5"><a href="#cb4-5" aria-hidden="true" tabindex="-1"></a> } <span class="cf">else</span> {</span> <span id="cb4-6"><a href="#cb4-6" aria-hidden="true" tabindex="-1"></a> <span class="fu">ji</span>(text)</span> <span id="cb4-7"><a href="#cb4-7" aria-hidden="true" tabindex="-1"></a> }</span> <span id="cb4-8"><a href="#cb4-8" aria-hidden="true" tabindex="-1"></a>}</span> <span id="cb4-9"><a href="#cb4-9" aria-hidden="true" tabindex="-1"></a></span> <span id="cb4-10"><a href="#cb4-10" aria-hidden="true" tabindex="-1"></a>glue_ji <span class="ot"><-</span> <span class="cf">function</span>(..., <span class="at">.envir =</span> <span class="fu">parent.frame</span>()) {</span> <span id="cb4-11"><a href="#cb4-11" aria-hidden="true" tabindex="-1"></a> <span class="fu">glue</span>(..., <span class="at">.open =</span> <span class="st">":"</span>, <span class="at">.close =</span> <span class="st">":"</span>, <span class="at">.envir =</span> .envir, <span class="at">.transformer =</span> emoji_transformer)</span> <span id="cb4-12"><a href="#cb4-12" aria-hidden="true" tabindex="-1"></a>}</span> <span id="cb4-13"><a href="#cb4-13" aria-hidden="true" tabindex="-1"></a><span class="fu">glue_ji</span>(<span class="st">"one :heart:"</span>)</span> <span id="cb4-14"><a href="#cb4-14" aria-hidden="true" tabindex="-1"></a><span class="co">#> one ❤️</span></span> <span id="cb4-15"><a href="#cb4-15" aria-hidden="true" tabindex="-1"></a><span class="fu">glue_ji</span>(<span class="st">"many :heart*:"</span>)</span> <span id="cb4-16"><a href="#cb4-16" aria-hidden="true" tabindex="-1"></a><span class="co">#> many 💘❤️💟💌</span></span></code></pre></div> </div> <div id="sprintf-transformer" class="section level3"> <h3>sprintf transformer</h3> <p>A transformer which allows succinct sprintf format strings.</p> <div class="sourceCode" id="cb5"><pre class="sourceCode r"><code class="sourceCode r"><span id="cb5-1"><a href="#cb5-1" aria-hidden="true" tabindex="-1"></a>sprintf_transformer <span class="ot"><-</span> <span class="cf">function</span>(text, envir) {</span> <span id="cb5-2"><a href="#cb5-2" aria-hidden="true" tabindex="-1"></a> m <span class="ot"><-</span> <span class="fu">regexpr</span>(<span class="st">":.+$"</span>, text)</span> <span id="cb5-3"><a href="#cb5-3" aria-hidden="true" tabindex="-1"></a> <span class="cf">if</span> (m <span class="sc">!=</span> <span class="sc">-</span><span class="dv">1</span>) {</span> <span id="cb5-4"><a href="#cb5-4" aria-hidden="true" tabindex="-1"></a> format <span class="ot"><-</span> <span class="fu">substring</span>(<span class="fu">regmatches</span>(text, m), <span class="dv">2</span>)</span> <span id="cb5-5"><a href="#cb5-5" aria-hidden="true" tabindex="-1"></a> <span class="fu">regmatches</span>(text, m) <span class="ot"><-</span> <span class="st">""</span></span> <span id="cb5-6"><a href="#cb5-6" aria-hidden="true" tabindex="-1"></a> res <span class="ot"><-</span> <span class="fu">eval</span>(<span class="fu">parse</span>(<span class="at">text =</span> text, <span class="at">keep.source =</span> <span class="cn">FALSE</span>), envir)</span> <span id="cb5-7"><a href="#cb5-7" aria-hidden="true" tabindex="-1"></a> <span class="fu">do.call</span>(sprintf, <span class="fu">list</span>(<span class="fu">glue</span>(<span class="st">"%{format}"</span>), res))</span> <span id="cb5-8"><a href="#cb5-8" aria-hidden="true" tabindex="-1"></a> } <span class="cf">else</span> {</span> <span id="cb5-9"><a href="#cb5-9" aria-hidden="true" tabindex="-1"></a> <span class="fu">eval</span>(<span class="fu">parse</span>(<span class="at">text =</span> text, <span class="at">keep.source =</span> <span class="cn">FALSE</span>), envir)</span> <span id="cb5-10"><a href="#cb5-10" aria-hidden="true" tabindex="-1"></a> }</span> <span id="cb5-11"><a href="#cb5-11" aria-hidden="true" tabindex="-1"></a>}</span> <span id="cb5-12"><a href="#cb5-12" aria-hidden="true" tabindex="-1"></a></span> <span id="cb5-13"><a href="#cb5-13" aria-hidden="true" tabindex="-1"></a>glue_fmt <span class="ot"><-</span> <span class="cf">function</span>(..., <span class="at">.envir =</span> <span class="fu">parent.frame</span>()) {</span> <span id="cb5-14"><a href="#cb5-14" aria-hidden="true" tabindex="-1"></a> <span class="fu">glue</span>(..., <span class="at">.transformer =</span> sprintf_transformer, <span class="at">.envir =</span> .envir)</span> <span id="cb5-15"><a href="#cb5-15" aria-hidden="true" tabindex="-1"></a>}</span> <span id="cb5-16"><a href="#cb5-16" aria-hidden="true" tabindex="-1"></a><span class="fu">glue_fmt</span>(<span class="st">"π = {pi:.3f}"</span>)</span> <span id="cb5-17"><a href="#cb5-17" aria-hidden="true" tabindex="-1"></a><span class="co">#> π = 3.142</span></span></code></pre></div> </div> <div id="safely-transformer" class="section level3"> <h3>safely transformer</h3> <p>A transformer that acts like <code>purrr::safely()</code>, which returns a value instead of an error.</p> <div class="sourceCode" id="cb6"><pre class="sourceCode r"><code class="sourceCode r"><span id="cb6-1"><a href="#cb6-1" aria-hidden="true" tabindex="-1"></a>safely_transformer <span class="ot"><-</span> <span class="cf">function</span>(<span class="at">otherwise =</span> <span class="cn">NA</span>) {</span> <span id="cb6-2"><a href="#cb6-2" aria-hidden="true" tabindex="-1"></a> <span class="cf">function</span>(text, envir) {</span> <span id="cb6-3"><a href="#cb6-3" aria-hidden="true" tabindex="-1"></a> <span class="fu">tryCatch</span>(</span> <span id="cb6-4"><a href="#cb6-4" aria-hidden="true" tabindex="-1"></a> <span class="fu">eval</span>(<span class="fu">parse</span>(<span class="at">text =</span> text, <span class="at">keep.source =</span> <span class="cn">FALSE</span>), envir),</span> <span id="cb6-5"><a href="#cb6-5" aria-hidden="true" tabindex="-1"></a> <span class="at">error =</span> <span class="cf">function</span>(e) <span class="cf">if</span> (<span class="fu">is.language</span>(otherwise)) <span class="fu">eval</span>(otherwise) <span class="cf">else</span> otherwise)</span> <span id="cb6-6"><a href="#cb6-6" aria-hidden="true" tabindex="-1"></a> }</span> <span id="cb6-7"><a href="#cb6-7" aria-hidden="true" tabindex="-1"></a>}</span> <span id="cb6-8"><a href="#cb6-8" aria-hidden="true" tabindex="-1"></a></span> <span id="cb6-9"><a href="#cb6-9" aria-hidden="true" tabindex="-1"></a>glue_safely <span class="ot"><-</span> <span class="cf">function</span>(..., <span class="at">.otherwise =</span> <span class="cn">NA</span>, <span class="at">.envir =</span> <span class="fu">parent.frame</span>()) {</span> <span id="cb6-10"><a href="#cb6-10" aria-hidden="true" tabindex="-1"></a> <span class="fu">glue</span>(..., <span class="at">.transformer =</span> <span class="fu">safely_transformer</span>(.otherwise), <span class="at">.envir =</span> .envir)</span> <span id="cb6-11"><a href="#cb6-11" aria-hidden="true" tabindex="-1"></a>}</span> <span id="cb6-12"><a href="#cb6-12" aria-hidden="true" tabindex="-1"></a></span> <span id="cb6-13"><a href="#cb6-13" aria-hidden="true" tabindex="-1"></a><span class="co"># Default returns missing if there is an error</span></span> <span id="cb6-14"><a href="#cb6-14" aria-hidden="true" tabindex="-1"></a><span class="fu">glue_safely</span>(<span class="st">"foo: {xyz}"</span>)</span> <span id="cb6-15"><a href="#cb6-15" aria-hidden="true" tabindex="-1"></a><span class="co">#> foo: NA</span></span> <span id="cb6-16"><a href="#cb6-16" aria-hidden="true" tabindex="-1"></a></span> <span id="cb6-17"><a href="#cb6-17" aria-hidden="true" tabindex="-1"></a><span class="co"># Or an empty string</span></span> <span id="cb6-18"><a href="#cb6-18" aria-hidden="true" tabindex="-1"></a><span class="fu">glue_safely</span>(<span class="st">"foo: {xyz}"</span>, <span class="at">.otherwise =</span> <span class="st">"Error"</span>)</span> <span id="cb6-19"><a href="#cb6-19" aria-hidden="true" tabindex="-1"></a><span class="co">#> foo: Error</span></span> <span id="cb6-20"><a href="#cb6-20" aria-hidden="true" tabindex="-1"></a></span> <span id="cb6-21"><a href="#cb6-21" aria-hidden="true" tabindex="-1"></a><span class="co"># Or output the error message in red</span></span> <span id="cb6-22"><a href="#cb6-22" aria-hidden="true" tabindex="-1"></a><span class="fu">library</span>(crayon)</span> <span id="cb6-23"><a href="#cb6-23" aria-hidden="true" tabindex="-1"></a><span class="fu">glue_safely</span>(<span class="st">"foo: {xyz}"</span>, <span class="at">.otherwise =</span> <span class="fu">quote</span>(<span class="fu">glue</span>(<span class="st">"{red}Error: {conditionMessage(e)}{reset}"</span>)))</span> <span id="cb6-24"><a href="#cb6-24" aria-hidden="true" tabindex="-1"></a><span class="co">#> foo: Error: object 'xyz' not found</span></span></code></pre></div> </div> <div id="variables-and-values-transformer" class="section level3"> <h3>“Variables and Values” transformer</h3> <p>A transformer that expands input of the form <code>{var_name=}</code> into <code>var_name = var_value</code>, i.e. a shorthand for exposing variable names with their values. This is inspired by an <a href="https://docs.python.org/3.8/whatsnew/3.8.html#f-strings-now-support-for-quick-and-easy-debugging">f-strings feature coming in Python 3.8</a>. It’s actually more general: you can use it with an expression input such as <code>{expr=}</code>.</p> <div class="sourceCode" id="cb7"><pre class="sourceCode r"><code class="sourceCode r"><span id="cb7-1"><a href="#cb7-1" aria-hidden="true" tabindex="-1"></a>vv_transformer <span class="ot"><-</span> <span class="cf">function</span>(text, envir) {</span> <span id="cb7-2"><a href="#cb7-2" aria-hidden="true" tabindex="-1"></a> regex <span class="ot"><-</span> <span class="st">"=$"</span></span> <span id="cb7-3"><a href="#cb7-3" aria-hidden="true" tabindex="-1"></a> <span class="cf">if</span> (<span class="sc">!</span><span class="fu">grepl</span>(regex, text)) {</span> <span id="cb7-4"><a href="#cb7-4" aria-hidden="true" tabindex="-1"></a> <span class="fu">return</span>(<span class="fu">identity_transformer</span>(text, envir))</span> <span id="cb7-5"><a href="#cb7-5" aria-hidden="true" tabindex="-1"></a> }</span> <span id="cb7-6"><a href="#cb7-6" aria-hidden="true" tabindex="-1"></a></span> <span id="cb7-7"><a href="#cb7-7" aria-hidden="true" tabindex="-1"></a> text <span class="ot"><-</span> <span class="fu">sub</span>(regex, <span class="st">""</span>, text)</span> <span id="cb7-8"><a href="#cb7-8" aria-hidden="true" tabindex="-1"></a> res <span class="ot"><-</span> <span class="fu">identity_transformer</span>(text, envir)</span> <span id="cb7-9"><a href="#cb7-9" aria-hidden="true" tabindex="-1"></a> n <span class="ot"><-</span> <span class="fu">length</span>(res)</span> <span id="cb7-10"><a href="#cb7-10" aria-hidden="true" tabindex="-1"></a> res <span class="ot"><-</span> <span class="fu">glue_collapse</span>(res, <span class="at">sep =</span> <span class="st">", "</span>)</span> <span id="cb7-11"><a href="#cb7-11" aria-hidden="true" tabindex="-1"></a> <span class="cf">if</span> (n <span class="sc">></span> <span class="dv">1</span>) {</span> <span id="cb7-12"><a href="#cb7-12" aria-hidden="true" tabindex="-1"></a> res <span class="ot"><-</span> <span class="fu">c</span>(<span class="st">"["</span>, res, <span class="st">"]"</span>)</span> <span id="cb7-13"><a href="#cb7-13" aria-hidden="true" tabindex="-1"></a> }</span> <span id="cb7-14"><a href="#cb7-14" aria-hidden="true" tabindex="-1"></a> <span class="fu">glue_collapse</span>(<span class="fu">c</span>(text, <span class="st">" = "</span>, res))</span> <span id="cb7-15"><a href="#cb7-15" aria-hidden="true" tabindex="-1"></a>}</span></code></pre></div> <div class="sourceCode" id="cb8"><pre class="sourceCode r"><code class="sourceCode r"><span id="cb8-1"><a href="#cb8-1" aria-hidden="true" tabindex="-1"></a><span class="fu">set.seed</span>(<span class="dv">1234</span>)</span> <span id="cb8-2"><a href="#cb8-2" aria-hidden="true" tabindex="-1"></a>description <span class="ot"><-</span> <span class="st">"some random"</span></span> <span id="cb8-3"><a href="#cb8-3" aria-hidden="true" tabindex="-1"></a>numbers <span class="ot"><-</span> <span class="fu">sample</span>(<span class="dv">100</span>, <span class="dv">4</span>)</span> <span id="cb8-4"><a href="#cb8-4" aria-hidden="true" tabindex="-1"></a>average <span class="ot"><-</span> <span class="fu">mean</span>(numbers)</span> <span id="cb8-5"><a href="#cb8-5" aria-hidden="true" tabindex="-1"></a>sum <span class="ot"><-</span> <span class="fu">sum</span>(numbers)</span> <span id="cb8-6"><a href="#cb8-6" aria-hidden="true" tabindex="-1"></a></span> <span id="cb8-7"><a href="#cb8-7" aria-hidden="true" tabindex="-1"></a><span class="fu">glue</span>(<span class="st">"For {description} {numbers=}, {average=}, {sum=}."</span>, <span class="at">.transformer =</span> vv_transformer)</span> <span id="cb8-8"><a href="#cb8-8" aria-hidden="true" tabindex="-1"></a><span class="co">#> For some random numbers = [28, 80, 22, 9], average = 34.75, sum = 139.</span></span> <span id="cb8-9"><a href="#cb8-9" aria-hidden="true" tabindex="-1"></a></span> <span id="cb8-10"><a href="#cb8-10" aria-hidden="true" tabindex="-1"></a>a <span class="ot"><-</span> <span class="dv">3</span></span> <span id="cb8-11"><a href="#cb8-11" aria-hidden="true" tabindex="-1"></a>b <span class="ot"><-</span> <span class="fl">5.6</span></span> <span id="cb8-12"><a href="#cb8-12" aria-hidden="true" tabindex="-1"></a><span class="fu">glue</span>(<span class="st">"{a=}</span><span class="sc">\n</span><span class="st">{b=}</span><span class="sc">\n</span><span class="st">{a * 9 + b * 2=}"</span>, <span class="at">.transformer =</span> vv_transformer)</span> <span id="cb8-13"><a href="#cb8-13" aria-hidden="true" tabindex="-1"></a><span class="co">#> a = 3</span></span> <span id="cb8-14"><a href="#cb8-14" aria-hidden="true" tabindex="-1"></a><span class="co">#> b = 5.6</span></span> <span id="cb8-15"><a href="#cb8-15" aria-hidden="true" tabindex="-1"></a><span class="co">#> a * 9 + b * 2 = 38.2</span></span></code></pre></div> </div> <!-- code folding --> <!-- dynamically load mathjax for 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