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Programming-Idioms

  • Scala
  • Go

Idiom #353 Test if list is sorted

Set the boolean b to true if the list items has all its elements in increasing order, false otherwise.

The order is not strict: the ordered list may contain duplicate elements.

import "slices"
b := slices.IsSorted(items)
classes
b := items.sorted and (items.count > 1) and (items[0] < items[1]);

Assumes items is a TStrings descendant.
A list with only 1 item cannot be said to be ordered, let alone ordered in an increasing way ;-)
New implementation...
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programming-idioms.org 
b := slices.IsSorted(items)
b := items.sorted and (items.count > 1) and (items[0] < items[1]);
b = sorted(items) == items
b = items.each_cons(2).all?{ _1 <= _2 } 

b = items.each_cons(2).all?{|a,b| a <= b }