> What is triggering the code evaluation of max(...) here?

"  @{[...]}  " is an idiomatic pseudo-operator by combining several mechanisms

• String interpolation work not only for arrays but also for dereferencing of arrays.

  " @{$a_ref} "

• The [...] marks an anonymous array-ref.

  " @{[ 1, 2, 3 ]} "

• Lists can also include code statements to be executed

  " @{[ 1, 2, some_code() ]} "

• The returned list will be included into the string.

    DB<6> p ">>> @{[ 1, 2, time() ]} <<<"
  >>> 1 2 1680647910 <<<
    DB<7>
  [download]

update

added code examples for each step

---

---

Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!

Titles consisting of a single word are discouraged, and in most cases are disallowed outright.

Read Where should I post X? if you're not absolutely sure you're posting in the right place.

Please read these before you post! —

• How do I compose an effective node title?
• How do I post a question effectively?
• Markup in the Monastery

Posts may use any of the Perl Monks Approved HTML tags:

a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr

You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)

	For:		Use:
	&		&
	<		&lt;
	>		&gt;
	[		&#91;
	]		&#93;

Link using PerlMonks shortcuts! What shortcuts can I use for linking?

See Writeup Formatting Tips and other pages linked from there for more info.