<HTML dir=ltr><HEAD><TITLE>[clean-list] Parsing: to drill or not to drill, that is the question</TITLE>
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<DIV dir=ltr><FONT face=Arial color=#000000 size=2>I just wrote constantWind to be working on a list of Char. Only after that I found out I wanted to combine it with parsers working on a list of [Char]. It shows that you can reuse the constantWind parser without having to re-engineer it to work on a list of [Char]. you could have done the latter also.</FONT></DIV>
<DIV dir=ltr><FONT face=Arial size=2>Erik Zuurbier</FONT></DIV></DIV>
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<FONT face=Tahoma size=2><B>Van:</B> clean-list-bounces@science.ru.nl namens metaperl<BR><B>Verzonden:</B> do 28-8-2008 16:30<BR><B>Aan:</B> clean-list@science.ru.nl<BR><B>Onderwerp:</B> [clean-list] Parsing: to drill or not to drill, that is the question<BR></FONT><BR></DIV>
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<P><FONT size=2>surfaceWind is a parser engineered to operate on [Char]<BR><BR>however constantWind is a parser engineered to operate on Char... but it<BR>then gets applied via drill to create a parser which operates on [Char]<BR><BR>Why would one be indirect and create a parser to operate on Char and then<BR>apply 'drill' to get what you intended to use:<BR><BR>surfaceWind :: Parser [Char] SurfaceWind t<BR>surfaceWind = "Surface Wind" :> p<BR>where p = (word constantWind) <&> \surfaceWind -> <!?> (word<BR>directionVariation)<BR> (\dir2->{surfaceWind & direction=dir2}) // if found<BR> surfaceWind // if nothing found<BR><BR>constantWind :: Parser Char SurfaceWind a<BR>constantWind = direction <&> \dir -><BR> speed <&> \(u,spd) -><BR> gust u <@ \g -> {direction=dir,speed=spd,gust=g}<BR><BR>--<BR>View this message in context: <A href="http://www.nabble.com/Parsing%3A-to-drill-or-not-to-drill%2C--that-is-the-question-tp19201847p19201847.html">http://www.nabble.com/Parsing%3A-to-drill-or-not-to-drill%2C--that-is-the-question-tp19201847p19201847.html</A><BR>Sent from the Clean mailing list archive at Nabble.com.<BR><BR>_______________________________________________<BR>clean-list mailing list<BR>clean-list@science.ru.nl<BR><A href="http://mailman.science.ru.nl/mailman/listinfo/clean-list">http://mailman.science.ru.nl/mailman/listinfo/clean-list</A><BR></FONT></P></DIV></BODY></HTML>