title: String template to set the default value of PARAMETER
body: <p>Is it possible, in ABAP, to evaluate string templates dynamically?</p>
  
  <p>Normally, you will have some string template in code that will be checked by the compiler. (The variables in the curly brackets are checked by the compiler at compile time).</p>
  
  <p>However, is it possible to have a string evaluated at runtime?</p>
  
  <p>So, instead of:</p>
  
  <pre><code>data(val) = |System ID: { sy-sysid }|.
  </code></pre>
  
  <p>I would like the string to be interpolated to come from elsewhere, for example:</p>
  
  <pre><code>parameter: p_file type string lower case default '/mnt/{ sy-sysid }/file.txt'.
  </code></pre>
  
  <p>In this case, I would like to have the value of <code>p_file</code> to be evaluated at runtime to substitute the variable (<code>sy-sysid</code>) with the runtime value.</p>
  
  <p>You could, of course, program your own substitution by finding all occurrences of variables with curly brackets with a regex expression, then evaluate the variable values with <code>ASSIGN</code> and substitute them back into the string, but I am looking for a built-in way to do this.</p>
  
  <p>Sorry, this is maybe a stupid example, but hopefully you understand what I mean. (If not, please let me know in the comments and I will try and clarify).</p>