Snippets discussion - productivity feature or teaching feature

[rkeithhill]

I guess I've gotten used to C# snippets that are "functional/productive". I find snippets like this in the PowerShell extension to be an awkward hybrid:

switch ($x)
{
    'value1' {  }
    {$_ -in 'A','B','C'} {}
    'value3' {}
    Default {}
}

Seriously, what are the odds that I'll have value1 as a case or a second or third case as shown above. I believe these were written to show how to use a feature i.e. they are teaching. That is admirable but as soon as the user learns the features of switch, this snippet becomes cumbersome because now it is a toss-up WRT how much code they have to "delete" to make the snippet conform to their intent versus how much they would have typed in the first place without using the snippet.

I propose that at the very least the "common" language features lean more towards being productivity snippets and not "teaching" snippets. I recommend changing the switch statement snippet to something like:

switch ($variable) {
    condition { action; break }
    Default {}
}

Where the cursor is put on a condtion placeholder second after $variable and then the action placeholder would be third.

BTW here are a few more examples of what I'm talking about:

try
{
    1/0
}
catch [DivideByZeroException]
{
    Write-Host "Divide by zero exception"
}
catch [System.Net.WebException],[System.Exception]
{
    Write-Host "Other exception"
}
finally
{
    Write-Host "cleaning up ..."
}

for ($i = 1; $i -lt 99; $i++)
{

}

Everybody who uses the try/catch/finally snippet is going to have to remove the DivideByZeroException and likely have to change the last catch to use an exception they want to catch (or not specify one at all). I believe there should a single exception there and it should be a placeholder. Likewise everybody is going to have to replace 99 in the for snippet. Might as well make it a placeholder.

[daviwil]

Agree completely, snippets should be functions to speed up coding. If we want to have educational snippets, it would be better as a different feature that doesn't overload the expectations of the snippets feature. Feel free to fix up any existing snippets that have extraneous stuff that isn't immediately useful!

[rkeithhill]

OK, I've retained the "example" style snippets but they all begin with ex- in the auto-completion list. All of the rest of the non ex- examples are focused on productivity, not on teaching. I've modified the organization of the snippets file to put all the example snippets at the top of the file.

I also added some new snippets to try out proph, enum, dsc ensure enum, parameter, parameter-path, parameter-literalpath and ex-path-processing.

[daviwil]

That's a great way to do it.

[rkeithhill]

Before the Feb drop I was thinking about updating the snippets to include the word "snippet" in the description. I find myself seeing foreach or while twice in the completion list where one is a keyword completion and the other is the snippet and I'm not sure which I will get. Thoughts?

[daviwil]

That sounds like a good idea to me. I've been confused by it in the past too.

[KirkMunro]

Just to add to the discussion, snippets in PowerShell is a sore point with me because they are just examples, not snippets in the sense of productivity as you guys already mentioned. With productivity in mind, if the productivity snippets for keywords are useful enough that I'd always want to use them, I'd prefer not seeing two choices (the keyword or the snippet), and having the snippet automatically applied when I apply completion to the word I'm typing. That might be a nice feature to offer as an option, especially since keyword completion by itself is pretty useless (there aren't a lot of really long keywords out there).

[daviwil]

Yeah, good point. It looks like the ISE gets around this by requiring you to invoke a different IntelliSense list that's solely for snippets. Since the PowerShell engine is returning the completion for these keywords, we'd need a way to filter them out in editors which have snippets. I think 'foreach' as a keyword completion is pretty pointless in an editor that has snippets.

Maybe we can just identify a set of keywords which will most often have snippets and just filter them out of code completion results entirely so that the snippets only show up? What do you think, Keith?

[daviwil]

This also could be an option that gets set in the LanguageService so that it can be enabled/disabled for different editors.

[rkeithhill]

snippets in PowerShell is a sore point with me because they are just examples

The snippets in PSES are now by default productivity oriented. Auto-completing the foreach snippet gives:

foreach ($item in $collection) {
    <== cursor place here
}

Where you get to tab between $item and $collection to change the variable name. There are still some "example" snippets but all of these are prefixed ex- e.g. ex-DSC resource provider (class-based).

Maybe we can just identify a set of keywords which will most often have snippets and just filter them out of code completion results entirely so that the snippets only show up? What do you think, Keith?

Or we could just filter out all keywords. Hmm, perhaps that is too extreme. Yeah, we could filter based on a blacklist. Would that list be static (in the code)? Or a setting?

[daviwil]

I'm fine with filtering them all out if we have reasonable snippet replacements for all of them, I just haven't evaluated what that would amount to yet. I'd say maybe having an on/off setting without any granularity might be nice until we see what kind of feedback we get.

[daviwil]

I'd also say we shouldn't even expose the setting to the user at first. Maybe people won't even care?