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# MOVENULLS -- Move all null elements to the end of the index array
#
# This procedure rearranges an array of row indices so that all rows with
# nulls in a particular column are moved to the end of the index array.
# The position of the nulls in the column is indicated by an array of null
# flags, whose length might be greater than the length of the array of
# indices, i.e., only a subset of the rows in a table might be in the index
# array.
#
# B.Simon 15-Dec-87 First Code
int procedure movenulls (nindex, nulflg, index)
int nindex # i: Number of indices
bool nulflg[ARB] # i: Array of null flags
int index[ARB] # io: Array of row indices
#--
int nelem, idx, jdx
begin
nelem = nindex
do idx = nindex, 1, -1 {
jdx = index[idx]
if (nulflg[jdx]) {
if (nelem != idx) {
index[idx] = index[nelem]
index[nelem] = jdx
}
nelem = nelem - 1
}
}
return (nelem)
end
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