Category talk:Wren-seq: Difference between revisions
→Source code: Added Lst.columns method.
(Added Seq.hasAdjDups method.) |
(→Source code: Added Lst.columns method.) |
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Line 814:
// As 'multiples' but where 'first' and 'multiplier' are the same.
static powers(first, n) { multiples(first, n, first) }
// Builds and returns a list of corresponding columns from a non-empty list 'a'
// of rows, where each row is a non-empty list of any element type. The number
// of columns in each row must be the same.
static columns(a) {
var nr = a.count
if (nr == 0) Fiber.abort("List must contain at least one row.")
var nc = a[0].count
if (nc == 0) Fiber.abort("Rows must have at least one column.")
if (a.skip(1).any { |e| e.count != nc }) {
Fiber.abort("Rows must all have the same number of columns.")
}
var cols = List.filled(nc, null)
for (j in 0...nc) {
cols[j] = List.filled(nr, 0)
for (i in 0...nr) cols[j][i] = a[i][j]
}
return cols
}
}
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