Category talk:Wren-str: Difference between revisions

Content added Content deleted
(→‎Source code: Added more versatile Str.replace and minor edit to Str.exchange method.)
(→‎Source code: Made Str.lshift/rshift methods more general.)
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// Performs a circular shift of the characters of 's' one place to the left.
// Performs a circular shift of the characters of 's' 'n' places to the left.
// If 'n' is negative performs a circular right shift by '-n' places instead.
static lshift(s) {
static lshift(s, n) {
if (!(s is String)) s = "%(s)"
if (!(s is String)) s = "%(s)"
if (!(n is Num) || !n.isInteger) Fiber.abort("'n' must be an integer.")
var chars = s.toList
var chars = s.toList
var count = chars.count
var count = chars.count
if (count < 2) return s
if (count < 2) return s
var t = chars[0]
if (n < 0) return rshift(s, -n)
for (i in 0..count-2) chars[i] = chars[i+1]
n = n % count
chars[-1] = t
if (n == 0) return s
for (i in 1..n) {
var t = chars[0]
for (j in 0..count-2) chars[j] = chars[j+1]
chars[-1] = t
}
return (count < 1000) ? Strs.concat_(chars) : Strs.concat(chars, 1000)
return (count < 1000) ? Strs.concat_(chars) : Strs.concat(chars, 1000)
}
}


// Performs a circular shift of the characters of 's' one place to the right.
// Performs a circular shift of the characters of 's' 'n' places to the right.
// If 'n' is negative performs a circular left shift by '-n' places instead.
static rshift(s) {
static rshift(s, n) {
if (!(s is String)) s = "%(s)"
if (!(s is String)) s = "%(s)"
if (!(n is Num) || !n.isInteger) Fiber.abort("'n' must be an integer.")
var chars = s.toList
var chars = s.toList
var count = chars.count
var count = chars.count
if (count < 2) return s
if (count < 2) return s
var t = chars[-1]
if (n < 0) return lshift(s, -n)
for (i in count-2..0) chars[i+1] = chars[i]
n = n % count
chars[0] = t
if (n == 0) return s
for (i in 1..n) {
var t = chars[-1]
for (j in count-2..0) chars[j+1] = chars[j]
chars[0] = t
}
return (count < 1000) ? Strs.concat_(chars) : Strs.concat(chars, 1000)
return (count < 1000) ? Strs.concat_(chars) : Strs.concat(chars, 1000)
}
}

// Convenience versions of the above methods which shift by just 1 place.
static lshift(s) { lshift(s, 1) }
static rshift(s) { rshift(s, 1) }


/* The indices (or ranges thereof) for all the following functions are measured in codepoints
/* The indices (or ranges thereof) for all the following functions are measured in codepoints
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