blob: 65b665f063f21bc6a3373486108929f6f01e58a8 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
|
⍝ assumes no ⍬s in source, chance of an infinite loop!
ArrayFormation←{
source←,¨⍺ ⍝ facilitate passing scalars
target←⍵
0=≢target: 1 ⍝ if we built the whole target, we are done
starters←⍸(⊢≡≢↑target⍨)¨source ⍝ which source lists are prefixes of target
0=≢starters: 0 ⍝ if there are no prefixes, we can't build the target
DoSuffix←{ ⍝ recurse, expending a prefix
target←target↓⍨≢⍵⊃source ⍝ drop found prefix from target
source←source/⍨0@⍵⊢1⍴⍨≢source ⍝ delete index ⍵ from sources, this is yucky why isn't there a primitive for this
source ArrayFormation target
}
∨/DoSuffix¨starters ⍝ any choice works
}
⎕←(2 3) 1 4 ArrayFormation 1 2 3 4
⎕←(1 3) (2 4) ArrayFormation 1 2 3 4
⎕←(9 1) (5 8) 2 ArrayFormation 5 8 2 9 1
⎕←1 3 ArrayFormation 1 2 3
⎕←⊂7 4 6 ArrayFormation 7 4 6
|
