Category talk:Wren-seq: Difference between revisions
→Source code: Added 'indexOfSlice' and 'isSliceOf' methods to Lst class.
(→Source code: Added indexOf method to FrozenList class.) |
(→Source code: Added 'indexOfSlice' and 'isSliceOf' methods to Lst class.) |
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Line 120:
static indexOf(a, value) { indexOf(a, value, 0) }
static indexOfAny(a, values) { indexOfAny(a, values, 0) }
// Returns the index at which the slice 's' is first found in 'a' or -1 if it is not present.
static indexOfSlice(a, s) {
isList_(a)
isList_(s)
var ac = a.count
var sc = s.count
if (ac == 0 || sc > ac) return -1
if (sc == 0) return 0
if (ac == 1) return (a[0] == s[0]) ? 0 : -1
if (sc == 1) return a.indexOf(s[0])
for (i in 0..ac-sc) {
if (a[i] == s[0]) {
var ok = true
for (j in i+1...i + sc) {
if (a[j] != s[j - i]) {
ok = false
break
}
}
if (ok) return i
}
}
return -1
}
// Returns true if 's' is a slice of 'a' or false otherwise.
static isSliceOf(a, s) { indexOfSlice(a, s) >= 0 }
// Exchanges the elements at indices 'i' and 'j' of 'a'.
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