I'd run this by someone who actually knows math, but afaik there are finitely many empty strings in any given string.<br><br>How many e's are in any given string? (Ignoring Unicode issues for now,) for each index in the string's indices, form a substring one character in length starting at that index and compare the value of that substring to e.<br><br>How many empty strings are in any given string? For each index in the string's indices, form a substring zero characters in length starting at that index and compare the value of that substring to an empty string.<br><br><br><div class="gmail_quote"><div dir="ltr">On Wed, Jul 20, 2016 at 17:35 Guillaume Lessard <<a href="mailto:glessard@tffenterprises.com">glessard@tffenterprises.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><br>
> On 20 juil. 2016, at 14:21, Xiaodi Wu <<a href="mailto:xiaodi.wu@gmail.com" target="_blank">xiaodi.wu@gmail.com</a>> wrote:<br>
><br>
> Doesn't your second argument undermine your first? If it's a trivial solution and one rarely ever considers empty strings when invoking `hasPrefix`, then returning the technically correct result must be a trivial departure in behavior.<br>
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I specifically used an example where the trivial solution (y=0 instead of y=exp(x)) is a pitfall.<br>
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How many empty strings are contained in any given string?<br>
If the answer is infinitely many, it sounds like a pitfall to me.<br>
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Cheers,<br>
Guillaume Lessard<br>
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</blockquote></div>