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63 lines
1.2 KiB
Go
63 lines
1.2 KiB
Go
package span
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import (
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"constraints"
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"github.com/jordanorelli/generic/iter"
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)
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// Span represents some range of integers
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type Span[T constraints.Integer] struct {
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Start T
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End T
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Step T
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}
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type spanIter[T constraints.Integer] struct {
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start T
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end T
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step T
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next T
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}
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func (s Span[T]) Iter() iter.Ator[T] {
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return &spanIter[T]{
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start: s.Start,
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end: s.End,
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step: s.Step,
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next: s.Start,
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}
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}
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func (s *spanIter[T]) Next(n *T) bool {
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if s.step == 0 || s.next < s.start || s.next >= s.end {
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return false
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}
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*n = s.next
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s.next += s.step
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return true
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}
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func (s spanIter[T]) Iter() iter.Ator[T] { return &s }
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// New creates a span of integers between start and end. The is analagous to
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// the "range" function in Python, but since range already means something in
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// Go, span is the chosen name to avoid confusion with Go's concept of range.
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// The created span is given a step size of 1.
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func New[T constraints.Integer](start, end T) Span[T] {
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return Span[T]{
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Start: start,
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End: end,
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Step: 1,
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}
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}
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// Step is the same as creating a span with a provided step value
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func Step[T constraints.Integer](start, end, step T) Span[T] {
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return Span[T]{
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Start: start,
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End: end,
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Step: step,
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}
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}
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