<div dir="auto">filter erases all elements not satisfying given predicate. deleteBy erases only the first element satisfying given predicate.</div><br><div class="gmail_quote"><div dir="ltr">2018년 11월 1일 (목) 12:17에 Vanessa McHale <<a href="mailto:vanessa.mchale@iohk.io">vanessa.mchale@iohk.io</a>>님이 작성:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
  
    
  
  <div text="#000000" bgcolor="#FFFFFF">
    <p>Isn't <tt>deleteBy</tt> achievable via a filter?<br>
    </p>
    <div class="m_7302352563316949845moz-cite-prefix">On 10/31/18 10:03 PM, Dannyu NDos
      wrote:<br>
    </div>
    <blockquote type="cite">
      
      <div dir="auto">It would be more ineffecient if I had to convert
        my lists to Data.Sets ot Data.Maps every time... For small
        lists, the operations are simple and practical. This doesn't
        have anything with generalization of type signatures anyway.</div>
      <br>
      <div class="gmail_quote">
        <div dir="ltr">2018년 11월 1일 (목) 11:58에 David Feuer <<a href="mailto:david.feuer@gmail.com" target="_blank" rel="noreferrer">david.feuer@gmail.com</a>>님이
          작성:<br>
        </div>
        <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
          <div dir="auto">
            <div>I don't think it's really so great that Data.List has a
              bunch of operations that are inefficient on lists.<br>
              <br>
              <div class="gmail_quote">
                <div dir="ltr">On Wed, Oct 31, 2018, 10:53 PM Dannyu
                  NDos <<a href="mailto:ndospark320@gmail.com" rel="noreferrer noreferrer" target="_blank">ndospark320@gmail.com</a>
                  wrote:<br>
                </div>
                <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
                  <div dir="ltr">
                    <div><a id="m_7302352563316949845m_-5550854795530768115m_-1011512877651145680gmail-v:deleteBy" class="m_7302352563316949845m_-5550854795530768115m_-1011512877651145680gmail-def" rel="noreferrer noreferrer noreferrer">I've suffered from
                        inconvenience due to the restricted type
                        signature. I'll be very glad if such
                        restrictions are lifted:<br>
                      </a></div>
                    <div><a id="m_7302352563316949845m_-5550854795530768115m_-1011512877651145680gmail-v:deleteBy" class="m_7302352563316949845m_-5550854795530768115m_-1011512877651145680gmail-def" rel="noreferrer noreferrer noreferrer"><br>
                      </a></div>
                    <div><a id="m_7302352563316949845m_-5550854795530768115m_-1011512877651145680gmail-v:deleteBy" class="m_7302352563316949845m_-5550854795530768115m_-1011512877651145680gmail-def" rel="noreferrer noreferrer noreferrer">deleteBy</a> :: (a ->
                      b -> <a href="http://hackage.haskell.org/package/base-4.12.0.0/docs/Data-Bool.html#t:Bool" title="Data.Bool" rel="noreferrer noreferrer noreferrer" target="_blank">Bool</a>)
                      -> a -> [b] -> [b]</div>
                    <div><a id="m_7302352563316949845m_-5550854795530768115m_-1011512877651145680gmail-v:deleteFirstsBy" class="m_7302352563316949845m_-5550854795530768115m_-1011512877651145680gmail-def" rel="noreferrer noreferrer noreferrer">deleteFirstsBy</a> :: (a
                      -> b -> <a href="http://hackage.haskell.org/package/base-4.12.0.0/docs/Data-Bool.html#t:Bool" title="Data.Bool" rel="noreferrer noreferrer noreferrer" target="_blank">Bool</a>)
                      -> [a] -> [b] -> [b]</div>
                    <div><a id="m_7302352563316949845m_-5550854795530768115m_-1011512877651145680gmail-v:intersectBy" class="m_7302352563316949845m_-5550854795530768115m_-1011512877651145680gmail-def" rel="noreferrer noreferrer noreferrer">intersectBy</a> :: (a
                      -> b -> <a href="http://hackage.haskell.org/package/base-4.12.0.0/docs/Data-Bool.html#t:Bool" title="Data.Bool" rel="noreferrer noreferrer noreferrer" target="_blank">Bool</a>)
                      -> [a] -> [b] -> [a] <br>
                    </div>
                    <div><br>
                    </div>
                    <div>I approve these versions because:</div>
                    <div>1. It makes more sense that the "usual"
                      `delete` and `intersect` functions are
                      specialization of the "By" operations, not the
                      vice versa.</div>
                    <div>2. Data.Map.Lazy module from <b>containers</b>
                      package has these kind of "By" operations.<br>
                    </div>
                    <div><br>
                    </div>
                    <div>The previous discussion about this in Sep 2016
                      didn't make much conclusion, so let the discussion
                      continue.<br>
                    </div>
                  </div>
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                </blockquote>
              </div>
            </div>
          </div>
        </blockquote>
      </div>
      <br>
      <fieldset class="m_7302352563316949845mimeAttachmentHeader"></fieldset>
      <pre class="m_7302352563316949845moz-quote-pre">_______________________________________________
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</pre>
    </blockquote>
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