<div dir="ltr"><div><span style="font-size:16px">It would be easier for the parser without curly braces:</span><br></div><div><span style="font-size:16px">+1</span></div><div><span style="font-size:16px"><br></span></div>I was gonna suggest not using curly-braces earlier but don't know enough about parsers to make such a request. Seeing as they're already required in other places, it would be advantageous to not require them again in this context.<div><br></div><div>Dave</div></div><div class="gmail_extra"><br><div class="gmail_quote">On Wed, Feb 8, 2017 at 6:28 PM, Steve Ratcliffe <span dir="ltr"><<a href="mailto:steve@parabola.me.uk" target="_blank">steve@parabola.me.uk</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><br>
Hi<span class=""><br>
<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
don't know if this helps:<br>
I see one possible implementation for a conditional rule like<br>
if (<exp>) {<br>
some rules<br>
} else {<br>
other rules<br>
}<br>
where <exp> would be something like tag=val, maybe also a parameter given to the program.<br>
If someone knows how to implement the syntax parser for such an if-thent-else clause the evaluation could simply<br>
</blockquote>
<br></span>
It would be easier for the parser without curly braces:<br>
<br>
if (<exp)<span class=""><br>
some rules<br>
else<br>
other rules<br></span>
endif<br>
<br>
I could make that work.<span class="HOEnZb"><font color="#888888"><br>
<br>
..Steve</font></span><div class="HOEnZb"><div class="h5"><br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
translate the if (<exp>) to a rule like<br>
exp {set special_var_x=true;}<br>
and then add this special tag with tag=true or tag!=true to each conditional rule.<br>
So, we would not need many changes in the evaluation of the rules, only in the parser.<br>
<br>
Gerd<br>
<br>
______________________________<wbr>__________<br>
Von: mkgmap-dev <<a href="mailto:mkgmap-dev-bounces@lists.mkgmap.org.uk" target="_blank">mkgmap-dev-bounces@lists.mkgm<wbr>ap.org.uk</a>> im Auftrag von Mike Baggaley <<a href="mailto:mike@tvage.co.uk" target="_blank">mike@tvage.co.uk</a>><br>
Gesendet: Dienstag, 7. Februar 2017 18:22:32<br>
An: <a href="mailto:mkgmap-dev@lists.mkgmap.org.uk" target="_blank">mkgmap-dev@lists.mkgmap.org.uk</a><br>
Betreff: Re: [mkgmap-dev] To do: If-Then-Else<br>
<br>
Hi Andrzej, can you not make use of mkgmap:country to handle this scenario?<br>
<br>
mkgmap:country=DZA | mkgmap:country=AGO | mkgmap:country=SHN |<br>
mkgmap:country=BEN ... {set continent=AF}<br>
<br>
continent=AF & landuse=farmland [0x10f01 level 1]<br>
<br>
Would mkgmap be better with a mkgmap:continent variable using<br>
place=continent added?<br>
<br>
Regards,<br>
Mike<br>
<br>
-----Original Message-----<br>
From: Andrzej Popowski [mailto:<a href="mailto:popej@poczta.onet.pl" target="_blank">popej@poczta.onet.pl</a>]<br>
Sent: 07 February 2017 12:39<br>
To: <a href="mailto:mkgmap-dev@lists.mkgmap.org.uk" target="_blank">mkgmap-dev@lists.mkgmap.org.uk</a><br>
Subject: Re: [mkgmap-dev] To do: If-Then-Else<br>
<br>
Hi Dave,<br>
<br>
I think the idea is to include some preprocessing capability to style<br>
interpreter.<br>
<br>
I develop a single style for my topo maps, but I need some possibility<br>
to get a small variation in style depending on region. For example I<br>
prefer to show landuse=farmland on a map of Africa but to remove it on a<br>
map of Europe. So instead of maintaining 2 nearly identical styles, I<br>
would like to get a conditional statement, something like:<br>
<br>
if (SHOW_FARMS) (<br>
landuse=farmland [0x10f01 level 1]<br>
)<br>
<br>
and then add (or not) an option to mkgmap like --style-define=SHOW_FARMS<br>
<br>
--<br>
Best regards,<br>
Andrzej<br>
<br>
<br>
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</blockquote>
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</div></div></blockquote></div><br><br clear="all"><div><br></div>-- <br><div class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr">Dave Swarthout<br>Homer, Alaska<br>Chiang Mai, Thailand<br>Travel Blog at <a href="http://dswarthout.blogspot.com" target="_blank">http://dswarthout.blogspot.com</a></div></div>
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