ListFunctions.psm1
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 |
Function BuildPredicate() { [CmdletBinding()] [OutputType([System.Predicate[object]])] param ( [Parameter(Mandatory = $true, ValueFromPipeline = $true)] [scriptblock] $ScriptBlock ) Begin { $rebuild = New-Object -TypeName 'System.Collections.Generic.List[string]' -ArgumentList 2 } Process { # Replace all instances of '$_' and '$PSItem' in the ScriptBlock with '$x' $sbString = $ScriptBlock.ToString().Replace('$_', '$x') $matchCol = [regex]::Matches($sbString, '\$PSItem', "IgnoreCase") $matchCol | Select-Object Value -Unique | ForEach-Object { $sbString = $sbString.Replace($PSItem.Value, [string]'$_') } # Split the ScriptBlock by new lines and add them to $rebuild $rebuild.AddRange(($sbString -split "`n")) if ($rebuild[0] -cnotmatch '^\s*param') { # If the first line is not the start of a 'param' block then... $rebuild.Insert(0, 'param ($x)') # ...insert one at the beginning of the list. } # Cast all joined strings from the list into a System.Predicate[object] [System.Predicate[object]][scriptblock]::Create(($rebuild -join "`n")) } } Function NewEqualityComparer() { [CmdletBinding()] param ( [Parameter(Mandatory = $false)] [Alias("Type", "t")] [ValidateScript( { $_ -is [type] -or $_ -is [string] })] [object] $GenericType = "[object]", [Parameter(Mandatory = $true)] [scriptblock] $EqualityScript, [Parameter(Mandatory = $true)] [scriptblock] $HashCodeScript ) $ms = [regex]::Matches($EqualityScript, '\$(x|y)(\s|\.)', "IgnoreCase") if ($ms | Assert-Any -Condition { $_.Success }) { $replace1 = [regex]::Replace($EqualityScript, '\$x(\s|\.)', '$args[0]$1', "IgnoreCase") $replace2 = [regex]::Replace($replace1, '\$y(\s|\.)', '$args[1]$1', "IgnoreCase") $EqualityScript = [scriptblock]::Create($replace2) } if ($HashCodeScript -match '\$[_](\.|\s)') { $HashCodeScript = [scriptblock]::Create([regex]::Replace($HashCodeScript, '\$[_](\.|\s)', '$args[0]$1')) } if ($GenericType -is [type]) { $GenericType = $GenericType.FullName } New-Object -TypeName "ListFunctions.ScriptBlockComparer[$GenericType]" -Property @{ EqualityTester = $EqualityScript HashCodeScript = $HashCodeScript } } Function Assert-All() { <# .SYNOPSIS Asserts all objects of a collections satisfy a condition. .DESCRIPTION Determines whether all elements of a sequence satisfy a condition. The condition is given in the form of a Filter ScriptBlock which will be converted into a System.Predicate (this means the scriptblock must return 'True/False'). This function is more useful the more complex the InputObjects become. .PARAMETER InputObject The collection(s) that contains the elements to apply the condition to. If an empty collection or null is passed, then the function will return 'False'. .PARAMETER Condition A ScriptBlock that each is run against each InputObject to satisfy the condition. The condition must be a predicate, meaning that a 'True/False' value is returned. .INPUTS System.Object - any .NET object or array of objects. .OUTPUTS System.Boolean .EXAMPLE @(1, 2, 3) | All { $_ -eq 1 } # returns 'False' .EXAMPLE @(1, 2, 3) | All { $_ -is [int] } # returns 'True' .EXAMPLE @( [pscustomobject]@{ Greeting = @{ 1 = "Hi" }}, [pscustomobject]@{ Greeting = @{ 2 = "Hey"}} ) | All { $_.Greeting.Count -gt 0 } # returns 'True' #> [CmdletBinding()] [Alias("Assert-AllObjects", "All-Objects", "All")] [OutputType([bool])] param ( [Parameter(Mandatory = $true, ValueFromPipeline = $true)] [AllowNull()] [AllowEmptyCollection()] [object[]] $InputObject, [Parameter(Mandatory = $true, Position = 0)] [scriptblock] $Condition ) Begin { $list = New-Object -TypeName "System.Collections.Generic.List[object]" } Process { if ($null -ne $InputObject -and $InputObject.Length -gt 0) { $list.AddRange($InputObject) } } End { if ($list.Count -gt 0) { $list.Where($Condition).Count -eq $list.Count } else { $false } } } Function Assert-Any() { <# .SYNOPSIS Asserts any object of a collection exists or matches a condition. .DESCRIPTION Determines whether any element of a sequence satisifies a condition. If no condition (scriptblock) is specified, then the functions determines whether the sequence contains any elements at all. This function is more useful the more complex the InputObjects become. .PARAMETER InputObject The collection(s) whose elements to apply the condition to. If the incoming collection(s) of objects are empty or null, the function returns 'False'. .PARAMETER Condition OPTIONAL. A ScriptBlock that each is run against each InputObject to satisfy the condition. The condition must be a predicate, meaning that a 'True/False' value is returned. .INPUTS System.Object - any .NET object or array of objects. .OUTPUTS System.Boolean .EXAMPLE @(1, 2, 3) | Any { $_ -eq 1 } # returns 'True' .EXAMPLE @(1, 2, 3) | Any # returns 'True' - (identical to '@(1, 2, 3).Count -gt 0') .EXAMPLE @( [pscustomobject]@{ Greeting = @{ 1 = "Hi" }}, [pscustomobject]@{ Greeting = @{ 2 = "Hey"}} ) | Any { $_.Greeting.ContainsKey(2) -and $_.Greeting[2] -eq "Hey" } # returns 'True' #> [CmdletBinding()] [Alias("Any-Object", "Any")] [OutputType([bool])] param ( [Parameter(Mandatory = $true, ValueFromPipeline = $true)] [AllowNull()] [AllowEmptyCollection()] [object[]] $InputObject, [Parameter(Mandatory = $false, Position = 0)] [scriptblock] $Condition ) Begin { $list = New-Object -TypeName "System.Collections.Generic.List[object]" } Process { if ($null -ne $InputObject -and $InputObject.Length -gt 0) { $list.AddRange($InputObject) } } End { if ($list.Count -gt 0) { if ($PSBoundParameters.ContainsKey("Condition")) { $list.Where($Condition).Count -gt 0 } else { $true } } else { $false } } } Function Find-IndexOf() { <# .SYNOPSIS Finds the index of the first element that matches a condition. .DESCRIPTION Searches for an element that matches the condition defined by the specified conditional ScriptBlock, and returns the zero-based index of the first occurrence within the entire collection of objects. When a 'StartIndex' value is specified, the function returns the first occurrence that starts from the first element of the specified index. When combined with 'Count', only the specified number of elements are searched. If no elements satisfy the condition specified, then function returns -1. This function is more useful the more complex the InputObjects become. @@!! IMPORTANT - READ NOTES SECTION !!@@ .PARAMETER InputObject The collection(s) of objects that are searched through. .PARAMETER Condition The predicate (scriptblock) that defines the conditions of the element to search for. .PARAMETER StartIndex The zero-based index where the search starts. .PARAMETER Count The number of elements in the section to search. .INPUTS System.Object - any .NET object or array of objects. .OUTPUTS System.Int32 - the zero-based index of the last occurrence that matches the condition if found; otherwise, - .EXAMPLE @(1, 2, 3, 1, 4) | Find-IndexOf { $_ -eq 1 } # returns '0' .EXAMPLE @(1, 2, 3, 1, 4) | Find-IndexOf { $_ -eq 3 -or $_ -eq 4 } # returns '2' .EXAMPLE @( [pscustomobject]@{ Whatev = @(1, 7) }, [pscustomobject]@{ Whatev = @(2, 7) }, [pscustomobject]@{ Whatev = @(3, @{ 7 = "Seven" }) }, [pscustomobject]@{ Whatev = @(4, @{ 7 = "Seven" }) }, [pscustomobject]@{ Whatev = @{ 7 = "Seven" }; Another = "Property" }, [pscustomobject]@{ Whatev = @( 4,5,6 ) } ) | Find-IndexOf { $_.Whatev -is [array] -and $($_.Whatev | Any { $PSItem -is [hashtable] -and $PSItem.ContainsKey(7) } ) } # returns '2' .NOTES @@!! IMPORTANT NOTE !!@@ -- In the conditional ScriptBlock, '$_' should ALWAYS represent the value of each InputObject. If using additional nested ScriptBlock inside the condition, DO NOT USE '$_'! Instead use '$PSItem'. The function replaces all instances of '$_' in order to create the System.Predicate[object]. Look at Example #3 to see an example of this. #> [CmdletBinding()] [Alias("Find-Index", "IndexOf")] [OutputType([int])] param ( [Parameter(Mandatory = $true, ValueFromPipeline = $true)] [object[]] $InputObject, [Parameter(Mandatory = $true, Position = 0)] [scriptblock] $Condition, [Parameter(Mandatory = $false)] [int] $StartIndex, [Parameter(Mandatory = $false)] [int] $Count ) Begin { $list = New-Object -TypeName "System.Collections.Generic.List[object]" $Predicate = BuildPredicate -ScriptBlock $Condition } Process { $list.AddRange($InputObject) } End { if (-not $PSBoundParameters.ContainsKey("Count")) { $list.FindIndex($StartIndex, $Predicate) } else { $list.FindIndex($StartIndex, $Count, $Predicate) } } } Function Find-LastIndexOf() { <# .SYNOPSIS Finds the index of the last element that matches a condition. .DESCRIPTION Searches for an element that matches the condition defined by the specified conditional ScriptBlock, and returns the zero-based index of the last occurrence within the entire collection of objects. When a 'StartIndex' value is specified, the function returns the last occurrence that extends from the first element to the specified index. When combined with 'Count', only the specified number of elements are searched. If no elements satisfy the condition specified, then function returns -1. This function is more useful the more complex the InputObjects become. @@!! IMPORTANT - READ NOTES SECTION !!@@ .PARAMETER InputObject The collection(s) of objects that are searched through. .PARAMETER Condition The predicate (scriptblock) that defines the conditions of the element to search for. .PARAMETER StartIndex The zero-based index of the backward search. .PARAMETER Count The number of elements in the section to search. .INPUTS System.Object - any .NET object or array of objects. .OUTPUTS System.Int32 - the zero-based index of the last occurrence that matches the condition if found; otherwise, -1. .EXAMPLE @(1, 2, 3, 1, 4) | Find-LastIndexOf { $_ -eq 1 } # returns '3' .EXAMPLE @(1, 2, 3, 1, 4) | Find-LastIndexOf { $_ -eq 1 -or $_ -eq 4 } # returns '4' .EXAMPLE @( [pscustomobject]@{ Whatev = @(1, 7) }, [pscustomobject]@{ Whatev = @(2, 7) }, [pscustomobject]@{ Whatev = @(3, @{ 7 = "Seven" }) }, [pscustomobject]@{ Whatev = @(4, @{ 7 = "Seven" }) }, [pscustomobject]@{ Whatev = @{ 7 = "Seven" }; Another = "Property" }, [pscustomobject]@{ Whatev = @( 4,5,6 ) } ) | Find-LastIndexOf { $_.Whatev -is [array] -and $($_.Whatev | Any { $PSItem -is [hashtable] -and $PSItem.ContainsKey(7) } ) } # returns '3' .NOTES @@!! IMPORTANT NOTE !!@@ -- In the conditional ScriptBlock, '$_' should ALWAYS represent the value of each InputObject. If using additional nested ScriptBlock inside the condition, DO NOT USE '$_'! Instead use '$PSItem'. The function replaces all instances of '$_' in order to create the System.Predicate[object]. Look at Example #3 to see an example of this. #> [CmdletBinding(DefaultParameterSetName = "None")] [Alias("Find-LastIndex", "LastIndexOf")] [OutputType([int])] param ( [Parameter(Mandatory = $true, ValueFromPipeline = $true)] [object[]] $InputObject, [Parameter(Mandatory = $true, Position = 0)] [scriptblock] $Condition, [Parameter(Mandatory = $true, ParameterSetName = "ByStartingIndex")] [int] $StartIndex, [Parameter(Mandatory = $false, ParameterSetName = "ByStartingIndex")] [int] $Count ) Begin { $list = New-Object -TypeName "System.Collections.Generic.List[object]" $Predicate = BuildPredicate -ScriptBlock $Condition } Process { $list.AddRange($InputObject) } End { if (-not $PSBoundParameters.ContainsKey("StartIndex")) { $StartIndex = $list.Count - 1 } if (-not $PSBoundParameters.ContainsKey("Count")) { $list.FindLastIndex($StartIndex, $Predicate) } else { $list.FindLastIndex($StartIndex, $Count, $Predicate) } } } Function New-HashSet() { <# .SYNOPSIS Creates a HashSet of unique values. .DESCRIPTION Creates a 'System.Collections.Generic.HashSet[T]' in order to store unique values into. .PARAMETER Capacity The total number of elements the set can hold without resizing. Default -- 0. .PARAMETER GenericType The constraining type that every object added into the list must be. .PARAMETER EqualityScript The scripblock that will check the equality between any 2 objects in the set. It must return a boolean (True/False) value. '$x' -or- '$args[0]' must represent the 1st item to be compared. '$y' -or - '$args[1]' must represent the 2nd item to be compared. .PARAMETER HashCodeScript The scriptblock that retrieve an item's hash code value. A "hash code" is a numeric value that is used to insert and identify an object in a "hash-based" collection. The easiest way to provide this through an object's 'GetHashCode()' method. Two objects that are equal return hash codes that are equal. However, the reverse is not true: equal hash codes do not imply object equality, becuase different (unequal) objects can have identical hash codes. .INPUTS System.Object[] -- The objects that will immediately added to the returned set. .OUTPUTS System.Collections.Generic.HashSet[T] -- where 'T' is the constrained generic type that all objects must be. .EXAMPLE # Create a HashSet[string] that ignores case for equality. $set = New-HashSet [string] -EqualityScript { $x -eq $y } -HashCodeScript { $_.ToLower().GetHashCode() } .EXAMPLE # Create a HashSet[object] that objects with the same 'Name' and 'Id' properties equal. $set = New-HashSet -EqualityScript { $x.Name -eq $y.Name -and $x.Id -eq $y.Id } .NOTES The EqualityScript must use either '$x' and '$y' -or- '$args[0]' and '$args[1]' in the scriptblock to properly identify the 2 comparing values. The HashCodeScript must use either '$_' -or- '$args[0]' in the scriptblock to properly identify the object whose hash code is retrieved. #> [CmdletBinding(DefaultParameterSetName = "None")] param ( [Parameter(Mandatory = $false)] [ValidateRange(0, [int]::MaxValue)] [int] $Capacity = 0, [Parameter(Mandatory = $false, Position = 0)] [Alias("Type", "t")] [ValidateScript( { $_ -is [type] -or $_ -is [string] })] [ValidateNotNull()] [object] $GenericType = "[object]", [Parameter(Mandatory = $false, ValueFromPipeline = $true)] [object[]] $InputObject, [Parameter(Mandatory = $true, ParameterSetName = "WithCustomEqualityComparer")] [scriptblock] $EqualityScript, [Parameter(Mandatory = $false, ParameterSetName = "WithCustomEqualityComparer")] [scriptblock] $HashCodeScript = { $_.GetHashCode() } ) Begin { if ($GenericType -is [type]) { $private:type = $GenericType $GenericType = $GenericType.FullName } if ($PSCmdlet.ParameterSetName -eq "WithCustomEqualityComparer") { $comparer = NewEqualityComparer -GenericType $GenericType -EqualityScript $EqualityScript -HashCodeScript $HashCodeScript } $set = New-Object -TypeName "System.Collections.Generic.HashSet[$GenericType]"($Capacity, $comparer) if ($null -eq $type) { $private:type = $set.GetType().GenericTypeArguments | Select-Object -First 1 } Write-Verbose "HashSet - GenericType $($private:type.FullName)" $private:type = $private:type.MakeArrayType() } Process { if ($PSBoundParameters.ContainsKey("InputObject")) { $set.UnionWith(($InputObject -as $private:type)) } } End { , $set } } Function New-List() { <# .SYNOPSIS Creates a strongly-typed list of objects. .DESCRIPTION Generates a strongly-typed list of objects that can be accessed by index. 'System.Collections.Generic.List[T]' This functions creates the list with the specified constrained type and the specified capacity. Objects can be immediately added to the list by explicit calling the "InputObject" parameter or by passing the objects through the pipeline. .PARAMETER Capacity The total number of elements the list can hold without resizing. Default -- 0. .PARAMETER GenericType The constraining type that every object added into the list must be. .PARAMETER InputObject A collection of objects that will initially added into the new list. .INPUTS System.Object[] -- Objects of any type of if constrained with a generic, objects must be of that type. .OUTPUTS System.Collections.Generic.List[T] -- where 'T' is the constrained object type. .EXAMPLE $list = New-List 780 -Type [string] .EXAMPLE $list = ,@('hi', 'hello', 'goodbye') | New-List 3 -GenericType [string] #> [CmdletBinding()] param ( [Parameter(Mandatory = $false)] [Alias("Type", "t")] [ValidateScript( { $_ -is [type] -or $_ -is [string] })] [object] $GenericType = "[object]", [Parameter(Mandatory = $false, Position = 0)] [Alias("c", "cap")] [ValidateRange(0, [int]::MaxValue)] [int] $Capacity = 0, [Parameter(Mandatory = $false, ValueFromPipeline = $true)] [object[]] $InputObject ) Begin { if ($GenericType -is [type]) { $private:type = $GenericType $GenericType = $GenericType.FullName } $private:list = New-Object "System.Collections.Generic.List[$GenericType]"($Capacity) Write-Verbose "List - Created with 'Capacity': $($private:list.Capacity)" if ($null -eq $type) { $private:type = $private:list.GetType().GenericTypeArguments | Select-Object -First 1 } Write-Verbose "List - GenericType: $($private:type.FullName)" $private:type = $private:type.MakeArrayType() } Process { if ($PSBoundParameters.ContainsKey("InputObject")) { $private:list.AddRange(($InputObject -as $private:type)) } } End { , $private:list } } Function Remove-All() { <# .SYNOPSIS Removes objects from collection(s) that satisfy a condition. .DESCRIPTION Removes all elements that match the conditions defined by the specified ScriptBlock. .PARAMETER InputObject The collection(s) of objects whose elements will be removed. .PARAMETER Condition The predicate (scriptblock) condition that determines whether any one element should be removed from the collection. .INPUTS System.Management.Automation.PSReference - [ref]. This must be a reference to an Array, Collection, or List (this includes Dictionaries; e.g. - Hashtables). .OUTPUTS None. .EXAMPLE $numbers = @(1, 2, 3) [ref]$numbers | Remove-All { $_ -eq 1 } # '$numbers' now equals: # @(2, 3) .EXAMPLE $strings = [System.Collections.ArrayList]@('hi', 'bye', 'so long') Remove-All -InputObject ([ref]$strings) -Condition { $_.Contains(' ') } # '$strings' now equals: # @('hi', 'bye') .EXAMPLE $hash = @{ "hi" = 1; "bye" = 2; "so long" = @{ multi = $true } } [ref]$hash | Remove-All { $_.Key -eq "Hi" -or $_.Value -is [hashtable] } # '$hash' now equals: # @{ "bye" = 2 } .NOTES If 'InputObject' is not a single-dimensional array or does not inherit from 'System.Collections.ICollection', then no removal operation will take place. @@!! IMPORTANT NOTE !!@@ -- In the conditional ScriptBlock, '$_' should ALWAYS represent the value of each InputObject. If using additional nested ScriptBlock inside the condition, DO NOT USE '$_'! Instead use '$PSItem'. The function replaces all instances of '$_' in order to create the System.Predicate[object]. #> [CmdletBinding()] [Alias("RemoveAll")] param ( [Parameter(Mandatory = $true, ValueFromPipeline = $true)] [ref] $InputObject, [Parameter(Mandatory = $true, Position = 0)] [scriptblock] $Condition ) Process { $Predicate = BuildPredicate $Condition if ($InputObject.Value.GetType().IsArray) { $elementType = $InputObject.Value.GetType().GetElementType() $list = New-Object -TypeName "System.Collections.Generic.List[object]" -ArgumentList $InputObject.Value.Length $list.AddRange(@($InputObject.Value)) [void] $list.RemoveAll($Predicate) $InputObject.Value = New-Object -TypeName "$($elementType.FullName)[]" $list.Count for ($i = 0; $i -lt $list.Count; $i++) { $InputObject.Value[$i] = $list[$i] } } elseif ($InputObject.Value -is [System.Collections.ICollection]) { $list = New-Object -TypeName "System.Collections.Generic.List[object]" -ArgumentList $InputObject.Value.Count $list.AddRange(@($InputObject.Value.GetEnumerator())) [void] $list.RemoveAll($Predicate) $newCol = [System.Activator]::CreateInstance($InputObject.Value.GetType()) foreach ($item in $list) { if ($item -is [System.Collections.DictionaryEntry]) { [void] $newCol.Add($item.Key, $item.Value) } else { [void] $newCol.Add($item) } } $InputObject.Value = $newCol } } } Function Remove-At() { <# .SYNOPSIS Removes item(s) of a collection at the specified indices. .DESCRIPTION Removes the elemetns at the specified indexes of the supplied collection of objects. When 'Index' and 'Count' are specified, the number ('Count') of elements from the specified index will be removed. There cannot be more than one (1) index specified when both parameters are used. .PARAMETER InputObject The collection(s) of objects whose elements will be removed. .PARAMETER Index The zero-based index of the element to remove. When used with 'Count', it is the starting index from which elements will be removed. .PARAMETER Count The number of elements to remove counting up from the starting index. .INPUTS System.Object - any .NET object or array of objects. .OUTPUTS System.Object[] - the resulting array sans the removed elements. .EXAMPLE @(1, 2, 3) | Remove-At 1 # returns: # @(1, 3) #> [CmdletBinding()] [Alias("RemoveAt")] param ( [Parameter(Mandatory = $true, ValueFromPipeline = $true)] [object[]] $InputObject, [Parameter(Mandatory = $true, Position = 0)] [int[]] $Index, [Parameter(Mandatory = $false)] [int] $Count ) Begin { if ($PSBoundParameters.ContainsKey("Count") -and $Index.Length -gt 1) { throw "When using 'Count', only 1 index may be specified at a time." } $list = New-Object -TypeName "System.Collections.Generic.List[object]" } Process { $list.AddRange($InputObject) } End { if (-not $PSBoundParameters.ContainsKey("Count")) { $itemsToRemove = foreach ($remIndex in $Index) { $list[$remIndex] } foreach ($item in $itemsToRemove) { [void] $list.Remove($item) } } else { $list.RemoveRange($Index[0], $Count) } $list } } |