Euphoria
Ticket #565:
Specify when parameters are optional in function declarations.
-
Reported by
nanochip
Dec 21, 2010
Not stating clearly in functions declarations that a parameter is optional only leads to confusion.
Please see regular expression related functions as an example.
Details
1. Comment by jeremy
Dec 21, 2010
Are you refering to something such as:
include std/regex.e
namespace regex
public function find(regex re, string haystack, integer from = 1,
option_spec options = DEFAULT,
integer size = get_ovector_size(re, 30))
? If so, any parameter with a default value is thus optional. Is there a different way you would like this to appear?
2. Comment by nanochip
Dec 22, 2010
I think it might not be obvious for most users that parameters with a value in the declaration of the function, are optional; not to mention when one of the default values is DEFAULT as in the example.
One alternative might be, like in most languages:
public function find(regex re, string haystack
[, integer from
[, option_spec options
[, integer size]]]
)
Default values for optional parameters: from = 1
option_spec options = DEFAULT
size = get_ovector_size(re, 30)
May be a matter of taste but I am one of those who gets confused with such declarations.
3. Comment by Shian_Lee
Dec 26, 2014
I any case using square brackets [] as in the example:
- public function find(regex re, string haystack [, integer from [, option_spec options [, integer size]]] )
- #
should be avoided in my opinion.
Unlike other languages, Euphoria normally using English words instead of punctuations; and using the same punctuation [] for different purposes (sequence index and optional parameter) is something Euphoria should avoid - keyword should be used instead, something like: , option integer from, option sequence options, option integer size
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