September 2017 Update

Task/Range-expansion/PowerShell/range-expansion-2.psh

@@ -0,0 +1,42 @@
+function Expand-Range
+{
+    [CmdletBinding()]
+    [OutputType([int])]
+    Param
+    (
+        [Parameter(Mandatory=$true,
+                   Position=0)]
+        [ValidateNotNullOrEmpty()]
+        [ValidatePattern('^[0-9,-]*$')]
+        [string]
+        $Range
+    )
+
+    try
+    {
+        if ($Range -match '-,')       # I'm not good enough to weed this case out with Regex
+        {
+            throw "Input string was not in a correct format."
+        }
+
+        [int[]]$output = $Range -split ',' | ForEach-Object {
+
+            [int[]]$array = $_ -split '(?<=\d)-'
+
+            if ($array.Count -gt 1)   # $array contains one or two elements
+            {
+                $array[0]..$array[1]  # two elements = start and end of range
+            }
+            else
+            {
+                $array                # one element = an integer
+            }
+        }
+    }
+    catch
+    {
+        throw "Input string was not in a correct format."
+    }
+
+    $output
+}

Task/Range-expansion/PowerShell/range-expansion-3.psh

@@ -0,0 +1 @@
+(Expand-Range "-6,-3--1,3-5,7-11,14,15,17-20") -join ", "