[postgis-devel] [PostGIS] #1500: ST_ConcatenateLines(line1, line2)

[PostGIS]

#1500: ST_ConcatenateLines(line1, line2)
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 Reporter:  strk         |       Owner:  pramsey      
     Type:  enhancement  |      Status:  new          
 Priority:  medium       |   Milestone:  PostGIS 2.0.0
Component:  postgis      |     Version:  trunk        
 Keywords:               |  
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 When dealing with topology it is useful to have a simple function that
 "sews" linestrings together respecting their ordering and direction.

 ST_LineMerge reverse lines as needed to find connection while the
 ST_ConcatenateLines should no nothing more than the sewing itself. No
 reversing, no reordering of arguments.

 The input should be already prepared to be an ordered array of linestring
 where the first point of each matches the end point of the previous. A
 single instance of the common vertex should be included in the result.

 The function should allow to construct non-simple lines, fully trusting
 and respecting the user input.

 Optionally (but not by default) the function might allow "patching" a gap
 between components by adding an additional segment connecting them (from
 end point of first to start point of second).

 Un-sewable conditions should be reported by throwing an exception.

 Would be nice to have this in 2.0.0, but we can probably also introduce it
 in 2.0.1 with no major drama.

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Ticket URL: <http://trac.osgeo.org/postgis/ticket/1500>
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