Some factors to consider:

• Is the function part of a public interface?
• Is the function only used in a single project?
• How likely is it that an incorrect argument is provided?
• What are the consequences of receiving bad arguments?
• Does the function fail safe or fail hard??

Should this function validate its input and warn/fail if a non-numeric value is provided? The built-in functions do not do this

Actually, they do.

>perl -wE"say sin('foo')"
Argument "foo" isn't numeric in sin at -e line 1.
0

>perl -wE"say cos('3.1415bar')"
Argument "3.1415bar" isn't numeric in cos at -e line 1.
-0.999999995707656
[download]

---

---

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.