The argument needs nothing, STR or ARRAY_REF as the argument and the return value is STR. get_next_key() is typical as the no argument case. This method is used to list up the content of files or retrieve the specific address in the file.
In other case, the return value may be a pair of strings.
KEY_STR => [ VALUE_STR_1 VALUE_STR_2 VALUE_STR_3 ]This is used as the return value to represent ARRAY_REF. For example, "actives" file of fml4 consists of lines which have plural space separeted entries. So it can be representated as a type of array.
firstname.lastname@example.org s=skip m=xxx.yyy.z # commnet email@example.com => [ s=skip m=xxx.yyy.z # comment ]
If retrieval value could be represented as ARRAY_REF, argument of store operations alsot needs ARRAY_REF.
It is summarized as follows. The argument is one of "nothing", "STR" or ARRAY_REF. The return value is either of STR of ARRAY_REF (array reference).
argument return value --------------------------------------- none => STR STR => STR none => [STR, STR, ... ] STR => [STR, STR, ... ]
Copyright (C) 1993-2017 Ken'ichi Fukamachi mail:< fukachan at fml.org >