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<p class="MsoNormal"><span lang="EN-US">Hi,<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">I found one transformation pattern frequent – to drop and add an element, or more generally to add end handler to an existing transformation.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">One common example; to replace a class element with a new one (no matter if present in the source classfile or not) can be implemented as:<o:p></o:p></span></p>
<p class="MsoNormal" style="background:white"><span style="font-size:10.0pt;font-family:"Courier New",serif;color:black;mso-ligatures:none;mso-fareast-language:EN-GB">ClassTransform.<i>dropping</i>(e -> e
</span><span style="font-size:10.0pt;font-family:"Courier New",serif;color:#336BDD;mso-ligatures:none;mso-fareast-language:EN-GB">instanceof</span><span style="font-size:10.0pt;font-family:"Courier New",serif;color:black;mso-ligatures:none;mso-fareast-language:EN-GB">
<i>WhateverElement</i>).andThen(ClassTransform.<i>endHandler</i>(clb -> clb.with(newWhateverElement)));<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">However this pattern compose heavy-weight chain of transformations (just to add an extra building code at the end).<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">I propose to allow light-weight chaining of end handlers to the existing transformations. For example ClassTransform::endHandler instance method may produce a copy of the transformation with attached additional end handler.
The example above may then look like:<o:p></o:p></span></p>
<p class="MsoNormal" style="background:white"><span style="font-size:10.0pt;font-family:"Courier New",serif;color:black;mso-ligatures:none;mso-fareast-language:EN-GB">ClassTransform.<i>dropping</i>(e -> e
</span><span style="font-size:10.0pt;font-family:"Courier New",serif;color:#336BDD;mso-ligatures:none;mso-fareast-language:EN-GB">instanceof</span><span style="font-size:10.0pt;font-family:"Courier New",serif;color:black;mso-ligatures:none;mso-fareast-language:EN-GB">
<i>WhateverElement</i>).<i>endHandler</i>(clb -> clb.with(newWhateverElement));<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Actual static factory method </span><span style="font-size:10.0pt;font-family:"Courier New",serif;color:black;mso-ligatures:none;mso-fareast-language:EN-GB">ClassTransform.<i>endHandler</i>(</span><span lang="EN-US" style="font-size:10.0pt;font-family:"Courier New",serif;color:black;mso-ligatures:none;mso-fareast-language:EN-GB">…
</span><span lang="EN-US">use can be refactored into </span><span style="font-size:10.0pt;font-family:"Courier New",serif;color:black;mso-ligatures:none;mso-fareast-language:EN-GB">ClassTransform.</span><i><span lang="EN-US" style="font-size:10.0pt;font-family:"Courier New",serif;color:black;mso-ligatures:none;mso-fareast-language:EN-GB">ACCEPT_ALL</span></i><span style="font-size:10.0pt;font-family:"Courier New",serif;color:black;mso-ligatures:none;mso-fareast-language:EN-GB">.<i>endHandler</i>(</span><span lang="EN-US" style="font-size:10.0pt;font-family:"Courier New",serif;color:black;mso-ligatures:none;mso-fareast-language:EN-GB">…<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Courier New",serif;color:black;mso-ligatures:none;mso-fareast-language:EN-GB"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">What do you think?<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Thanks,<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Adam<o:p></o:p></span></p>
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