<p>There is an existing API:
Dict() Event {...}</p>
<p>I want to change it to take a parameter:
Dict(bool compact) Event {...}</p>
<p>I want to do this without impacting callers of prior apis. say old callers will NOT get compact - unless they change the API.</p>
<p>In C++ there is a default value - where i could say Dict (bool compact = false) {} - there is no such thing in go AFAIK.
How do i achieve this in golang ? Here are the ways i could think of - can u suggest a method pls ?</p>
<ol>
<li><p>new API - CompactDict () {} - but the caller has to deal with two APIs instead of one API with two values for a single param.</p></li>
<li><p><HACK> change API to Dict(compact ...bool).. - this way the API can take in zero parameters (current callers) and one or more parameters. If there are more, will take the first one as the valid one and ignore the rest..</p></li>
</ol>
<p>Your comments are appreciated..</p>
<hr/>**评论：**<br/><br/>Sythe2o0: <pre><p>The ways you suggest are the easier ways to do it. </p>
<p>In the future, a way to do this would be to define the functions you want to be able to add more parameters to as taking in a variadic set of <a href="https://dave.cheney.net/2014/10/17/functional-options-for-friendly-apis" rel="nofollow">functional options</a>. This involves more boilerplate on your part.</p></pre>
