bde | utilities for calculating bond dissociation energies

you could try this:

Use combinations instead permutations and for each values of tuple sum values together:

• Unfortunately, as of PowerShell 7.2.1, the automatic $? variable has no meaningful value after calling a written-in-PowerShell function (as opposed to a binary cmdlet) . (More immediately, even inside the function, $? only reflects $false at the very start of the catch block, as Mathias notes).

  • If PowerShell functions had feature parity with binary cmdlets, then emitting at least one (non-script-terminating) error, such as with Write-Error, would set $? in the caller's scope to $false, but that is currently not the case.

  • You can work around this limitation by using $PSCmdlet.WriteError() from an advanced function or script, but that is quite cumbersome. The same applies to $PSCmdlet.ThrowTerminatingError(), which is the only way to create a statement-terminating error from PowerShell code. (By contrast, the throw statement generates a script-terminating error, i.e. terminates the entire script and its callers - unless a try / catch or trap statement catches the error somewhere up the call stack).

  • See this answer for more information and links to relevant GitHub issues.

• As a workaround, I suggest:

  • Make your function an advanced one, so as to enable support for the common -ErrorVariable parameter - it allows you to collect all non-terminating errors emitted by the function in a self-chosen variable.

    • Note: The self-chosen variable name must be passed without the $; e.g., to collection in variable $errs, use -ErrorVariable errs; do NOT use Error / $Error, because $Error is the automatic variable that collects all errors that occur in the entire session.

    • You can combine this with the common -ErrorAction parameter to initially silence the errors (-ErrorAction SilentlyContinue), so you can emit them later on demand. Do NOT use -ErrorAction Stop, because it will render -ErrorVariable useless and instead abort your script as a whole.

  • You can let the errors simply occur - no need for a try / catch statement: since there is no throw statement in your code, your loop will continue to run even if errors occur in a given iteration.

    • Note: While it is possible to trap terminating errors inside the loop with try / catch and then relay them as non-terminating ones with $_ | Write-Error in the catch block, you'll end up with each such error twice in the variable passed to -ErrorVariable. (If you didn't relay, the errors would still be collected, but not print.)

  • After invocation, check if any errors were collected, to determine whether at least one key wasn't backed up successfully.

  • As an aside: Of course, you could alternatively make your function output (return) a Boolean ($true or $false) to indicate whether errors occurred, but that wouldn't be an option for functions designed to output data.

Here's the outline of this approach:

First of all, your function is slightly weighed down by making extra string slices to pass down at every iteration. If the string you're currently working with is length m you're doing O(m + (m-1) + (m-2) ... + 1) = O(m^2) extra work every function call to make string slices, but you could just be passing down indices to iterate between. You could also do with collecting characters of a given combo in a list and joining them in the end, as building a string of size characters 1 character at a time with an immutable string type is an O(size^2) operation when you could be getting away with one final O(size) operation to join a generated combo before printing. So I would make these small changes, which well help make the complexity analysis a little simpler too:

You can remove one call of list():

I'm not sure if I understand you correctly. If you want to remove some words from some string then basically it can be done this way:

Try this code

You want to filter your array using the string length:

Your actual error is from because you have str(..).str(...) and there isn't a "someting".str(...) function.

However, you are ignoring the fact that match can return None. You have to check that match actually returned something and if not return the original