Types/Turtle/Repeat.ps1
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<# .SYNOPSIS Repeats Turtle Commands .DESCRIPTION Repeats Turtle Commands any number of times. Repeat is the original loop statement in Turtle graphics. .NOTES Repetition can be performed in many ways in PowerShell. Any example of repeat can also be written as an array with that series of steps, multiplied by the repeat count. ~~~PowerShell turtle repeat 3 [rotate 120 forward 42] # Produces the same shape as... turtle 'rotate',120,'forward',42 * 3 # Produces the same shape as... turtle @( foreach ($n in 1..3) { 'rotate', 120, 'forward', 42 } ) # Produces the same shape as... turtle @( foreach ($n in 1..3) { 'rotate' 120 'forward' 42 } ) ~~~ Because repeat parses each step each time, repeat is likely to be one of the slower ways to repeat. .EXAMPLE turtle repeat 3 [rotate (360/3) forward 42] save ./tri.svg .EXAMPLE turtle repeat 6 [rotate (360/6) forward 42] save ./hex.svg .EXAMPLE turtle repeat 7 [rotate (360/7) star 42 7] save ./starFlower.svg .EXAMPLE turtle repeat 4 [rotate (360/4) forward 42 repeat 3 [rotate 120 forward 42]] save ./r.svg .EXAMPLE turtle repeat 6 [rotate (360/6) forward 42 repeat 3 [rotate 120 forward 4.2]] save ./r2.svg .EXAMPLE turtle repeat 9 [rotate ( 360/9 ) forward 84 repeat 6 [rotate ( 360/6 ) forward 42 repeat 3 [rotate ( 360/3 ) forward 4.2]]] save ./r3.svg #> param( # The repeat count. # This will be rounded down to the nearest integer and converted into an absolute value. [double] $RepeatCount, # The steps to repeat. [Parameter(ValueFromRemainingArguments)] [PSObject[]] $Command ) # If there was no repeat count, return this if (-not $RepeatCount) { return $this } $floorCount = [Math]::Abs([Math]::Floor($RepeatCount)) if ($floorCount -ge 1) { $this = $this | turtle @($Command * $floorCount) } return $this |