I don't know why you replied to my point about C with your thoughts about Perl interfaces, but thanks. In Perl there are many options, including returning a list of results (with a result status as first entry), or a hash-ref with a "status" member.

In C, dealing with memory management is important. One can document who is responsible for deallocating data whose pointer is returned. Another option, used in recent PDL, is to return a pdl_error struct that has as members:

• an integer for the error type (including none)
• a char * pointer for any error text
• a flag saying whether that char * would need freeing after use (so if the string needed sprintf-ing and therefore first malloc-ing, that works without memory leaks)

Easy, and seems to have no problems so far (except thread-safe realloc for error-accumulation in Windows, but that was straightforward given previous work in PDL on that).

Parenthetically, the idea behind that is so that all PDL functions can return these thingies on error, instead of using a C-level exception mechanism. That means the PDL C library can start being used in other C-language applications, or have an interface for other dynamic languages.

---

---

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.