Designated initializers

Functions so marked in this documentation use standard C designated initializers and compound literals to allow you to omit, call by name, or change the order of inputs. The following examples are all equivalent.

The standard format:

apop_text_to_db("infile.txt", "intable", 0, 1, NULL);

Omitted arguments are left at their default vaules:

apop_text_to_db("infile.txt", "intable");

You can use the variable's name, if you forget its ordering:

apop_text_to_db("infile.txt", "intable", .has_col_name=1, .has_row_name=0);

If an un-named element follows a named element, then that value is given to the next variable in the standard ordering:

apop_text_to_db("infile.txt", "intable", .has_col_name=1, NULL);

• There is some overhead to checking for defaults; in cases that are more function-calling than actual calculation, this could slow the code by up to 25%. If this is noticeable for your situation, you can pass on this convenient form and call the underlying function directly, by adding _base to the name and giving all arguments:

apop_text_to_db_base("infile.txt", "intable", 0, 1, NULL);

• If one of the optional elements is an RNG, see Auto-allocated RNGs on what happens when you don't provide an RNG.
• For exhaustive details on implementation of the above (should you wish to write new functions that behave like this) see the Implementation of optional arguments page.