http://dev.clojure.org/jira This file is an XML representation of an issue en-us 4.4 649 25-07-2011 http://dev.clojure.org/jira/browse/MATCH-39 core.match <p>It is useful, to be able to constrain a match on a map value to limit the set of keys present in the value, without enforcing that the keys are all present in the value.</p> <p>The current :only option, enforces a strict matching of keys.</p> <p>{{(let [x {:a 1} (match <span class="error">&#91;x&#93;</span> [({:a _ :b _} :only <span class="error">&#91;:a :b&#93;</span>)])}} =&gt; doesn't match</p> <p>This came up trying to write a precondition on the argument of a function, which allowed optional keys, but wanted to restrict the overall set of keys.</p> MATCH-39

Allow matching of map expressions to restrict the set of keys present in the value to a subset of a specified set of keys

Enhancement Major Resolved Duplicate David Nolen Hugo Duncan Mon, 21 Nov 2011 11:03:28 -0600 Sun, 2 Jun 2013 11:36:18 -0500 Sun, 2 Jun 2013 11:36:18 -0500 0 0 <div class="code panel" style="border-width: 1px;"><div class="codeContent panelContent"> <pre class="code-java">(match x ({:c 1} :has [:a :b]) :a0 ...)</pre> </div></div> <p>or</p> <div class="code panel" style="border-width: 1px;"><div class="codeContent panelContent"> <pre class="code-java">(match x ({:c 1} :contains [:a :b]) :a0 ...)</pre> </div></div> <p>Seems reasonable.</p> <p>Ah misunderstood. You want something like :allowed.</p> <p>This is a variant of <a href="http://dev.clojure.org/jira/browse/MATCH-70" title="Matches against maps are treated as wildcards, even though they are not"><del>MATCH-70</del></a>. You can not specify that some keys must be present by specifying the key and the specifying that the value of the key is a wildcard.</p> Global Rank