Mercurial > repos > public > sbplib_julia

comparison src/LazyTensors/tuple_manipulation.jl @ 997:20c376dffe84 refactor/lazy_tensors

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Move tuple functions to their own file
author Jonatan Werpers <jonatan@werpers.com>
date Fri, 18 Mar 2022 21:26:02 +0100
parents
children 0905cec43d2e
comparison
equal deleted inserted replaced
996:aa72f067e771 997:20c376dffe84
1 """
2 split_index(::Val{dim_before}, ::Val{dim_view}, ::Val{dim_index}, ::Val{dim_after}, I...)
3
4 Splits the multi-index `I` into two parts. One part which is expected to be
5 used as a view, and one which is expected to be used as an index.
6 Eg.
7 ```
8 split_index(Val(1),Val(3),Val(2),Val(1),(1,2,3,4)) -> (1,:,:,:,4), (2,3)
9 ```
10
11 `dim_view` controls how many colons are in the view, and `dim_index` controls
12 how many elements are extracted from the middle.
13 `dim_before` and `dim_after` decides the length of the index parts before and after the colons in the view index.
14
15 Arguments should satisfy `length(I) == dim_before+B_domain+dim_after`.
16
17 The returned values satisfy
18 * `length(view_index) == dim_before + dim_view + dim_after`
19 * `length(I_middle) == dim_index`
20 """
21 function split_index(::Val{dim_before}, ::Val{dim_view}, ::Val{dim_index}, ::Val{dim_after}, I...) where {dim_before,dim_view, dim_index,dim_after}
22 I_before, I_middle, I_after = split_tuple(I, Val(dim_before), Val(dim_index))
23
24 view_index = (I_before..., ntuple((i)->:, dim_view)..., I_after...)
25
26 return view_index, I_middle
27 end
28
29 # TODO: Can this be replaced by something more elegant while still being type stable? 2020-10-21
30 # See:
31 # https://github.com/JuliaLang/julia/issues/34884
32 # https://github.com/JuliaLang/julia/issues/30386
33 """
34 slice_tuple(t, Val(l), Val(u))
35
36 Get a slice of a tuple in a type stable way.
37 Equivalent to `t[l:u]` but type stable.
38 """
39 function slice_tuple(t,::Val{L},::Val{U}) where {L,U}
40 return ntuple(i->t[i+L-1], U-L+1)
41 end
42
43 """
44 split_tuple(t::Tuple{...}, ::Val{M}) where {N,M}
45
46 Split the tuple `t` into two parts. the first part is `M` long.
47 E.g
48 ```julia
49 split_tuple((1,2,3,4),Val(3)) -> (1,2,3), (4,)
50 ```
51 """
52 function split_tuple(t::NTuple{N,Any},::Val{M}) where {N,M}
53 return slice_tuple(t,Val(1), Val(M)), slice_tuple(t,Val(M+1), Val(N))
54 end
55
56 """
57 split_tuple(t::Tuple{...},::Val{M},::Val{K}) where {N,M,K}
58
59 Same as `split_tuple(t::NTuple{N},::Val{M})` but splits the tuple in three parts. With the first
60 two parts having lenght `M` and `K`.
61 """
62 function split_tuple(t::NTuple{N,Any},::Val{M},::Val{K}) where {N,M,K}
63 p1, tail = split_tuple(t, Val(M))
64 p2, p3 = split_tuple(tail, Val(K))
65 return p1,p2,p3
66 end
67
68
69 """
70 flatten_tuple(t)
71
72 Takes a nested tuple and flattens the whole structure
73 """
74 flatten_tuple(t::NTuple{N, Number} where N) = t
75 flatten_tuple(t::Tuple) = ((flatten_tuple.(t)...)...,) # simplify?
76 flatten_tuple(ts::Vararg) = flatten_tuple(ts)