Perlguts: standardize on the _argument_stack

[richardleach]

Prior to this commit, the same stack was referred to as the "argument stack" in some places and the "value stack" in others.

The former seems to have greater precedence and is the only variant used in other pod docs, so instances of the latter term have been reworded for consistency and reduced reader confusion.

Closes #21443

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• This set of changes does not require a perldelta entry.

[Leont]

IMO value stack is a much better name than argument stack (even if the latter has more history), most obviously because it's not only used for argument but also for return values.

[tonycoz]

I think "value stack" is the better name, but most of perl (comments, other documentation) calls it the "argument stack".

So if this does rename to "value stack" it should mention the "argument stack" name.

[leonerd]

I added the "value stack" wording when I wrote about the various stacks in perlguts, largely because of Leon's observation there - it isn't just for arguments into a function, but also return values out of it. I'd prefer standardising on "value" rather than "argument" anyway, for that reason.

[iabyn]

On Mon, Apr 13, 2026 at 07:22:18AM -0700, Paul Evans wrote: I added the "value stack" wording when I wrote about the various stacks in perlguts, largely because of Leon's observation there - it isn't just for arguments into a function, but also return values out of it. I'd prefer standardising on "value" rather than "argument" anyway, for that reason.

Personally I prefer 'argument stack' because 'value stack' doesn't really give a strong clue as to what you're referring to. Most of the perl stacks contain values of one sort or another, while 'argument' is a strong hint, even if it's not technically 100% correct. And I would argue that it *is* technically correct: return values pushed by functions and perl ops will be arguments to subsequent functions and perl ops. (all IMHO).