Javier,
The cause of the +’s dates back to ancient times. When proj (the command line application) was originally created everything in argv would have been treated as a parameter for the command. To distinguish between regular parameters such as -f or -l and projection parameters such as +proj, +a or +ellps the plusses were used. Internally the +’s would have been stripped if I remember correctly. So that’s the explanation for the +-syntax. Today we would just wrap the proj-string in quotes, as you suggest, but I assume that wasn’t an option back in the day. At some point init-files were introduced and here it wasn’t necessary to include the plusses because it was obvious that projection parameters were given, although the +’s were/are allowed in init-files. I assume it just made sense to not use the +-syntax in this context at the time. Like you, I prefer the +-syntax as it makes it very obvious that we're are dealing with proj-strings but I know some people feel differently about that. One thing that is definitely clear is that mixing the two different styles of notation confuses people. For this reason I have always used the +-syntax in all documentation I have written. I encourage everyone else to do the same. /Kristian On Thu, 8 Feb 2024 at 10:44, Javier Jimenez Shaw via PROJ < [email protected]> wrote: > Hi > > I wanted to know if I can combine a pipeline where some entries do have a > "+" prefix and other doesn't (yes, it is ugly, I know it) > I found the method "pj_shrink" that, among other things, removes "+" > preceded by a space. So I deduce that the answer was "yes". > > That rises the question (actually the question was there before, but today > I found pj_shrink): why the "+" before every entry? Is it just to make it > clearer and easier in the command line, not needing quotes for the entire > expression? Is there anything else I do not see? > > I prefer (visually) the expression with "+"s. Somehow I find it nicer ;) > But I have seen that old expressions don't have it, and I am curious to > know the reason to change it. > > Thanks > .___ ._ ..._ .. . ._. .___ .. __ . _. . __.. ... .... ._ .__ > _______________________________________________ > PROJ mailing list > [email protected] > https://lists.osgeo.org/mailman/listinfo/proj >
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