在 Stack Overflow 上的另一个问题中,答案包括以下函数:
julia> function nzcols(b::SubArray{T,2,P,Tuple{UnitRange{Int64},UnitRange{Int64}}}) where {T,P<:SparseMatrixCSC}
return collect(i+1-start(b.indexes[2])
for i in b.indexes[2]
if b.parent.colptr[i]<b.parent.colptr[i+1] &&
inrange(b.parent.rowval[nzrange(b.parent,i)],b.indexes[1]))
end
nzcols (generic function with 3 methods)
并且解析没有错误。之前添加换行符时where
为了可读性,突然出现错误:
julia> function nzcols(b::SubArray{T,2,P,Tuple{UnitRange{Int64},UnitRange{Int64}}})
where {T,P<:SparseMatrixCSC}
return collect(i+1-start(b.indexes[2])
for i in b.indexes[2]
if b.parent.colptr[i]<b.parent.colptr[i+1] &&
inrange(b.parent.rowval[nzrange(b.parent,i)],b.indexes[1]))
end
ERROR: syntax: space before "{" not allowed in "where {"
最后,当参数列表括号移至where
行,错误再次消失:
julia> function nzcols(b::SubArray{T,2,P,Tuple{UnitRange{Int64},UnitRange{Int64}}}
) where {T,P<:SparseMatrixCSC}
return collect(i+1-start(b.indexes[2])
for i in b.indexes[2]
if b.parent.colptr[i]<b.parent.colptr[i+1] &&
inrange(b.parent.rowval[nzrange(b.parent,i)],b.indexes[1]))
end
nzcols (generic function with 3 methods)
这种语法背后的逻辑是什么?是否应该修复?