Cac/additional extensions#85
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| guard let lastElement = last else { return "" } | ||
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| return reduce("") { partialResult, element in | ||
| if partialResult.isEmpty { |
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split into if's instead to reduce nesting like so
if partialResult.isEmpty {
return element
}
if element == lastElement {
return partialResult + end + element
}
return partialResult + by + elementbut it might equally be written as
if partialResult.isEmpty {
return element
}
let isLastElement = element == lastElement
let concatElement = isLastElement.map(ifTrue: end, ifFalse: by)
return partialResult + concatElement + element
| var head: Element? { first } | ||
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| /// Removes the first element and retuns a new `Array` containing the rest of the elements. | ||
| var tail: [Element] { Array(dropFirst()) } |
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this should be a function. computed properties are meant for constant operations (O(1))
this is in the best case O(n).
the rational behind this is many, one is: its super easy to use in loops, which would produce quadratic (or worse) runtime performance + the amount of memory consumption is also a concern. besides this does not "access" an element on the array, it actually creates a whole new array. that is very "unexpected" based on a property (usually a "property" is a "property" of a given thing, not a computation per se).
| } | ||
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| /// Return the indexed element if within boundaries, else `nil` | ||
| func get(index: Int) -> Element? { |
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given the weird synergy this should potentially be called "getOrNil" to highlight the intention. that way the function is close to self documenting.
| var nilIfEmpty: [Element]? { isEmpty ? nil : self } | ||
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| /// Splits the `Array` into two dependent on the "shouldAppendToFirst-Argument", where the first `Array` contains the elements that match the bool and the second `Array` contains the rest. | ||
| func split(by shouldAppendToFirst: (Element) -> Bool) -> ([Element], [Element]) { |
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only thought here is whenever one should make a struct for the result to name the first and second as to match the lambda argument.
| return Calendar.current.date(byAdding: component, value: value, to: self) ?? self | ||
| } | ||
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| func date(bySubtracting component: Calendar.Component, value: Int) -> Date { |
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please take the current calendar as a optional parameter with default value to Calendar.current (in case someone is using this with a non default calendar).
func date(
bySubtracting component: Calendar.Component,
value: Int,
withCalendar: Calendar = Calendar.current
) -> Date {
withCalendar.date(
byAdding: component,
value: -value,
to: self
) ?? self
}
| Calendar.current.date(byAdding: component, value: -value, to: self) ?? self | ||
| } | ||
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| func alignTo(resolution: Calendar.Component) -> Date { |
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same here (wrt to the current calendar as a default paramter)
func alignTo(
resolution: Calendar.Component,
withCalendar: Calendar = Calendar.current
) -> Date {
var dateComponents = withCalendar.dateComponents(
Set([.year, .month, .day, .hour, .minute, .second, .nanosecond, .timeZone]),
from: self)
switch resolution {
case .year:
dateComponents.setValue(0, for: .month)
dateComponents.setValue(0, for: .day)
dateComponents.setValue(0, for: .hour)
dateComponents.setValue(0, for: .minute)
dateComponents.setValue(0, for: .second)
dateComponents.setValue(0, for: .nanosecond)
case .month:
dateComponents.setValue(0, for: .day)
dateComponents.setValue(0, for: .hour)
dateComponents.setValue(0, for: .minute)
dateComponents.setValue(0, for: .second)
dateComponents.setValue(0, for: .nanosecond)
case .day:
dateComponents.setValue(0, for: .hour)
dateComponents.setValue(0, for: .minute)
dateComponents.setValue(0, for: .second)
dateComponents.setValue(0, for: .nanosecond)
case .hour:
dateComponents.setValue(0, for: .minute)
dateComponents.setValue(0, for: .second)
dateComponents.setValue(0, for: .nanosecond)
case .minute:
dateComponents.setValue(0, for: .second)
dateComponents.setValue(0, for: .nanosecond)
case .second:
dateComponents.setValue(0, for: .nanosecond)
default:
break
}
return NSCalendar.current.date(from: dateComponents) ?? self
}another note is that if this switch was split into seperate functions, the code would naturally happen without duplication (eg, alignToYear would set the month to 0, then call allignToMonth)
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