arr(e, dim);
    if (dim[0] == 0)
      throw GDLException("Array dimensions must be greater than 0");

but in arr()

...
      if (ret < 0) throw GDLException(BadDims);
...
      if (newDim < 1) throw GDLException(BadDims);

GDL> help,/lib, name='*arr'
Library procedures (0):
Library functions (14):
res=BYTARR([8 Args],NOZERO)
res=COMPLEXARR([8 Args],NOZERO)
res=DBLARR([8 Args],NOZERO)
res=DCOMPLEXARR([8 Args],NOZERO)
res=FLTARR([8 Args],NOZERO)
res=INTARR([8 Args],NOZERO)
res=LON64ARR([8 Args],NOZERO)
res=LONARR([8 Args],NOZERO)
res=OBJARR([8 Args])                                      <<---- missing in GDL
res=PTRARR([8 Args],ALLOCATE_HEAP)      <<---- missing in GDL
res=STRARR([8 Args],NOZERO)                    <<---- to be removed in GDL 
res=UINTARR([8 Args],NOZERO)
res=ULON64ARR([8 Args],NOZERO)
res=ULONARR([8 Args],NOZERO)
% At $MAIN$