Filter as autoload trigger; why does this work?

Question

In my efforts to use PS consoles more and CMD consoles less, I've been "porting" my environment over. One of the things I can't live without is my 'cd aliases'. I have several aliases like: "src=cd /d c:\src" (loaded in doskey). Separate
functions for each alias seemed kludgy, so after a bit of playing around, I came up the little module below to mimic the functionality. The function takes a look at the alias that invoked it and sets the location based on values in a hashtable.
Since the aliases are dynamically created and thus aren't available to trigger the autoload, I decided to add a filter to do the triggering (I could just import the module in my profile, but I try to keep my profile lean).
My thought was that I could type 'src' and if the module wasn't loaded, it would cause the autoload to happen which would override the filter 'src' with the alias 'src'. Typing 'src' a second time would actually set my location to my source directory.
When I tested the 'filter autoload' however, I was pleasantly surprised that not only did it autoload the module, but it did the set-location on the
first invocation.
My guess is that PS sees the command 'src' and when it's passed looks at the modules that can satisfy the command. Finding a filter named 'src' in CdAlias.psm1, it autoloads. Then PS, knowing that the needed module is now loaded, resolves 'src' against the
now-current environment, finds the alias, resolves that to Set-XLocation and we are off to the races. That said, I'm only guessing here, and since this seems like something that could be useful in other places, it would be cool if someone could confirm my
guess or explain what's really happening.
thanks,
K.
Note: This is the prototype, I will actually store the hashtable in the registry along with functions to edit the entries.
<#
.Synopsis
Sets location based on the alias name used to call the function
.DESCRIPTION
Uses the name of the alias used to call the function to look up
a path in the script-scoped dictionary 'xlocation' then sets
the location to that value.
.PARAMETER ChildPath
Optional child path, if passed it will be joined with the base.
.NOTES
Not sure why the filter trick works, but it does. Since src is my
most commonly used alias location, I can use it to auto-load. What
really confuses me is that it still sets the location to src the
first time I type it.
#>
function Set-XLocation
Param
[string]$ChildPath
$k = $MyInvocation.InvocationName
if ($Script:xlocation.ContainsKey($k))
Set-Location -Path (Join-Path -Path $Script:xlocation[$k] -ChildPath $ChildPath)
else
Write-Warning "`$xlocation does not contain the key '$k'."
$Script:xlocation = @{
src = 'C:\src';
one = 'C:\src\one';
zero = 'C:\src\zero';
mod = "$mod";
foreach ($k in $Script:xlocation.Keys) { Set-Alias -Name $k -Value Set-XLocation }
filter src
Export-ModuleMember -Function Set-XLocation -Alias *

Answer 1

I do not understand what the issue is.  If you have to create a filter for every alias you are not really gaining anything over defining a function or alias.
I do not believe the filter does anything except create a reference:
PS C:\src> get-alias src
CommandType     Name                                              
ModuleName
Alias           src -> Set-XLocation                              
CDAlias
¯\_(ツ)_/¯