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Re^5: $1 not "freezing" in an addition

by ikegami (Pope)
on Dec 17, 2012 at 13:12 UTC ( #1009163=note: print w/replies, xml ) Need Help??


in reply to Re^4: $1 not "freezing" in an addition
in thread $1 not "freezing" in an addition

lvalue context has nothing to do with scalar/void/list context.

lvalue and lvalue context are not the same thing.

An lvalue context is a context where an expression must produce an lvalue. In contrast, an rvalue context is a context where code may produce an rvalue.

Example of lvalue contexts:

  • Sub arguments.
  • The arguments to some functions.
  • The operand of the reference operator.
  • The LHS operand of assignment operators.
  • foreach's list.

When using $1,$2... in an expression ( anything you can legally say in a spot where a value is required ) you should quote to stringify and preserve the current value.

No, it's stupid to do $x = "$1";.

...though I admit the lvalue context is not sufficient (e.g. $bar = "$1" + foo();).

Replies are listed 'Best First'.
Re^6: $1 not "freezing" in an addition
by Anonymous Monk on Dec 17, 2012 at 13:42 UTC

    ... An lvalue context is a context where an expression must produce an lvalue ...

    That is confusing, the $1 in  bar = "$1" + foo(); is not a location where you can assign (use = ) a value , what?

    No, it's stupid to do $x = "$1";

    Eh?

      I don't understand your questions.

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[TCLion]: I am breaking down the line and putting the date in the correct order during output
[TCLion]: at least that's the plan
[1nickt]: Corion this looks good, from the pod: "there are 9000+ variations that are detected correctly in the test files (see t/data/* for most of them). If you can think of any that I do not cover, please let me know."
[TCLion]: some moron put the date like this : Mon Feb 20 09:31:30 2017
[Corion]: 1nickt: Yes, the module sounds promising indeed
[1nickt]: "putting the date in correct order" how?
[Corion]: TCLion: Whee ;)
[TCLion]: need to put like this : 2017-02-20 09:30:53
[1nickt]: That's why I asked if you are using DateTime. It has a large number of supporting modules (the author likes the term 'eco-system') so if you are already creating a DateTime obj from your dates, this module would read in the mnoron-formatted 1s seamlessly
[TCLion]: when I put the date together it looks like : 2017-Feb-24 (month is the problem)

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