<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><div>On 9 May 2008, at 12:21, Dave Stubbs wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; "><br></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">The mapping to numbers doesn't gain us anything. It doesn't let us do</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">anything we can't already do, or make it any easier as far as I can</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">see.</div></blockquote><div><br></div><div>If the database, which is accessed by programmers, was numerically based, it would be be more amenable to algorithmic logic. At the simplest level, selecting elements with values above/below certain levels. The numbers would of course have to follow some logical pattern. Similar procedures using the current tags involve clumsier code like 'motorway OR trunk OR primary' and, if users are actually typing these words in (rather than selecting from human-friendly menus presented by the editor) a typo such as 'secodnary' cold corrupt the database and prevent the feature being seen by map viewers or routing engines for example.</div><br><blockquote type="cite"><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "><br></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">I think you were actually suggesting something like "type=11" -- where</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">10-20 means roads, 30-40 could mean railways etc. But as far as this</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">argument goes it doesn't really make much difference, other than</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">leaving us with a massive allocation problem which has been neatly</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">sidestepped by using free-form tagging.</div></blockquote><div><br></div><div>Yes free-form tagging avoids having to decide on a pattern and allows for open-ended evolution, but it doesn't work if it's completely free-form. I could describe many roads around here as 'highway=country lane" but would they get rendered? The fact that there are tagging recommendations acknowledges that anarchy would not work. But a data structure would have to allow change and evolution (at the simplest level, leaving spare numbers for future use) and this is a challenge.</div><br><blockquote type="cite"><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "><br></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">Indeed point missed again.</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">We DON'T DO (sorry Richard) highway=red. We do highway=primary and you</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">can make that any colour you like... same as you can do with</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">highway=13/type=13 -- it makes no difference is my point. Numbering</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">the highways won't help.</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "><br></div></blockquote><div><br></div>Now I'm confused. I'm not suggesting numbers to avoid red highways for goodness' sake!</div><div><br><blockquote type="cite"> <blockquote type="cite"><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "><br></div></blockquote><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">It could yes. There are a couple of issues with this mostly to do with</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">actually maintaining the style sheets and providing the processing</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">power/disk space.</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "><br></div></blockquote><div><br></div><div>Moore's Law should take care of those :-)</div><br><blockquote type="cite"><blockquote type="cite"><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "><font class="Apple-style-span" color="#0000DD"><br></font><br></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">No problemo! Special viewers like the cycle map would simply apply their own</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">filters. And with well-structured data a map viewer could even have settings</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">(eg. cycle routes on/off) allowing it to be customised by the user, making a</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">proliferation of specialist viewers unnecessary.</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "><br></div> </blockquote><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "><br></div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">Hmm.. yes, maybe. But the point of your e-mail was essentially</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; ">numbering everything, and that really doesn't help us with this goal.</div><div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; min-height: 14px; "><br></div></blockquote><br></div><div>It's just that numbers are easier for programmers (see above). Users would never see them. They would see words in their own language and the viewer/editor would map words to numbers.</div><div><br></div><div>elvin</div><br></body></html>