( I didn't mean to post Re^13: chopping a string into slices - is there a more elegant way to do it?. I meant to start fresh and post the following instead. )

You're basically saying that [...]

My point is simply parens don't create lists except when empty. That's it.

LanX is contradicting that, saying that parens can sometimes create a list. My rebuttal is:

  1. There are important differences between scalar and list assignment operators,
  2. Parens on the LHS of an assignment can force the selection of one operator over the other, and
  3. It's not because parens magically create lists some of the time.

perl as I understand it:

  1. Parens on the LHS of an assignment operator force the selection of the list assignment operator.
  2. The list assignment operator creates a list of both its operands.

The abstraction pushed by LanX, if I understand him correctly:

  1. Parens on the LHS of an assignment operator force the creation of a list.
  2. A list on the LHS of an assignment operator forces the RHS operand of the assignment operator to be treated as a list.

He hasn't had a chance to explain how that accounts for the difference in the output of scalar(($a)=5) and scalar($a=5)

Context is a run-time issue, so that is a completely separate thing and can't influence which assignment we pick.

Sometimes context is known at run-time, but not always. 

>perl -MO=Concise -e"f()" 2>&1 | find "entersub"
5     <1> entersub[t2] vKS/TARG,1 ->6
                       ^
                       |
                       void

>perl -MO=Concise -e"0+f()" 2>&1 | find "entersub"
6        <1> entersub[t2] sKS/TARG,1 ->7
                          ^
                          |
                          scalar

>perl -MO=Concise -e"print f()" 2>&1 | find "entersub"
6        <1> entersub[t2] lKS/TARG,1 ->7
                          ^
                          |
                          list

>perl -MO=Concise -e"return f()" 2>&1 | find "entersub"
6        <1> entersub[t2] KS/TARG,1 ->7
                          ^
                          |
                          unknown at compile-time

[download]

It's used by the optimizer. 

>perl -MO=Concise -e"'foo'"
3  <@> leave[1 ref] vKP/REFC ->(end)
1     <0> enter ->2
2     <;> nextstate(main 1 -e:1) v ->3
-     <0> ex-const v ->3                  <-- The constant in void
-e syntax OK                                  context was removed
                                              from the execution path.

[download]

In reply to Re^13: chopping a string into slices - is there a more elegant way to do it? by ikegami
in thread chopping a string into slices - is there a more elegant way to do it? by rovf

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