Regent: Unable to assign ispace to declaration of variable type ispace

[syamajala]

import "regent"
local c = regentlib.c

task main()
  var colors : ispace(int3d)
  var dim = 0

  if dim == 0 then
    colors = ispace(int3d, int3d{2, 1, 1})
  elseif dim == 1 then
    colors = ispace(int3d, int3d{1, 2, 1})
  elseif dim == 2 then
    colors = ispace(int3d, int3d{1, 1, 2})
  end
end

regentlib.start(main)

The above example results in the following:

/home/seshu/dev/legion/language/src/regent/type_check.t:4235: Errors reported during typechecking.
index_space_bug.rg:9: type mismatch in assignment: expected ispace(int3d) but got ispace(int3d)
    colors = ispace(int3d, int3d{2, 1, 1})
         ^

stack traceback:
        [C]: in function 'error'
        /home/seshu/dev/terra/src/terralib.lua:388: in function 'finishandabortiferrors'
        /home/seshu/dev/legion/language/src/common/report.t:56: in function 'error'
        /home/seshu/dev/legion/language/src/regent/type_check.t:4235: in function 'fn'
        /home/seshu/dev/terra/src/asdl.lua:16: in function 'map'
        /home/seshu/dev/legion/language/src/regent/type_check.t:3884: in function 'block'
        /home/seshu/dev/legion/language/src/regent/type_check.t:3902: in function 'fn'
        /home/seshu/dev/terra/src/asdl.lua:16: in function 'map'
        /home/seshu/dev/legion/language/src/regent/type_check.t:3884: in function 'block'
        /home/seshu/dev/legion/language/src/regent/type_check.t:4612: in function </home/seshu/dev/legion/language/src/regent/type_check.t:4545>
        /home/seshu/dev/legion/language/src/regent/passes.t:69: in function </home/seshu/dev/legion/language/src/regent/passes.t:57>
        index_space_bug.rg:4: in main chunk

If this is in fact invalid code the error message should probably be fixed because right now it is nonsensical to a user.

[elliottslaughter]

The error message is an instance of #491. It may be fixed by #583 but there are still some blocking issues around that one.

For now, you have to do this by making the dims conditional. Assignment on "special" types such as ispaces and regions isn't supported (until #583 merges).