Posts: 597
Threads: 110
Joined: Apr 2022
Reputation:
34
This is something I want in BAM. If QB64pe already has a similar function with a different name, I'd set up BAM's IFF function with the same name.
Code: (Select All) _GetUrlKey$ = IFF( step2%, LEFT$(step1$, step2% - 1 ), step1$)
Posts: 2,698
Threads: 327
Joined: Apr 2022
Reputation:
217
Posts: 207
Threads: 13
Joined: Apr 2022
Reputation:
52
(06-03-2023, 07:43 PM)SMcNeill Wrote: What does an IFF do?
I only know the IFF (Interchange File Format) introduced by "Electronic Arts" in 1985 https://github.com/1fish2/IFF, but that's obviously not what he thinks of according to his example.
Posts: 597
Threads: 110
Joined: Apr 2022
Reputation:
34
06-03-2023, 08:08 PM
(This post was last modified: 06-03-2023, 08:13 PM by CharlieJV.)
(06-03-2023, 07:43 PM)SMcNeill Wrote: What does an IFF do?
From this Wikipedia article:
Code: (Select All) IIf(expr, truepart, falsepart)
Although the code-volume-savings is nothing to brag about at all, it is very nice cognitively (semantically?) for assigning values to variables (and maybe some other circumstances I'm not thinking of).
So putting the focus on a variable:
Code: (Select All) variable = IIF( expr, truevalue, falsevalue )
instead of putting the focus on an IF THEN ELSE statement:
Code: (Select All) IF expr THEN variable = truevalue ELSE variable = falsevalue
Posts: 597
Threads: 110
Joined: Apr 2022
Reputation:
34
If of interest.
IIF is like conditional (ternary) operators ...
... in C++:
Code: (Select All) (condition) ? true-clause : false-clause
... in javascript:
Code: (Select All) condition ? exprIfTrue : exprIfFalse
Posts: 1,586
Threads: 59
Joined: Jul 2022
Reputation:
52
I get by like this:
Code: (Select All) dim i as _integer64, f as _float, x as _integer64, y as _float, s as string
i = iff(x > 5, x - 1, x * 2)
f = ifff(y < 0, 1, sqr(y))
s = iffs$(x = 0, "true", "false")
end
function iff&& (cond%%, truevalu&&, falsvalu&&)
if cond%% then
iff&& = truevalu&&
exit function
end if
iff&& = falsvalu&&
end function
function ifff## (cond%%, truevalu##, falsvalu##)
if cond%% then
ifff## = truevalu##
exit function
end if
ifff## = falsvalu##
end function
function iffs$ (cond%%, truevalu as string, falsvalu as string)
if cond%% then
iffs$ = truevalu
exit function
end if
iffs$ = falsvalu
end function
It requires three functions, one for integers, another for floating point and another for strings, that's the main drawback. But be glad BASIC doesn't have a "boolean" type that would have prevented the straight-out use of a condition which is evaluated and passed along as integer value.
Posts: 597
Threads: 110
Joined: Apr 2022
Reputation:
34
06-03-2023, 10:59 PM
(This post was last modified: 06-03-2023, 10:59 PM by CharlieJV.)
(06-03-2023, 10:32 PM)mnrvovrfc Wrote: I get by like this:
Code: (Select All) dim i as _integer64, f as _float, x as _integer64, y as _float, s as string
i = iff(x > 5, x - 1, x * 2)
f = ifff(y < 0, 1, sqr(y))
s = iffs$(x = 0, "true", "false")
end
function iff&& (cond%%, truevalu&&, falsvalu&&)
if cond%% then
iff&& = truevalu&&
exit function
end if
iff&& = falsvalu&&
end function
function ifff## (cond%%, truevalu##, falsvalu##)
if cond%% then
ifff## = truevalu##
exit function
end if
ifff## = falsvalu##
end function
function iffs$ (cond%%, truevalu as string, falsvalu as string)
if cond%% then
iffs$ = truevalu
exit function
end if
iffs$ = falsvalu
end function
It requires three functions, one for integers, another for floating point and another for strings, that's the main drawback. But be glad BASIC doesn't have a "boolean" type that would have prevented the straight-out use of a condition which is evaluated and passed along as integer value.
BAM programs being interpreted by javascript (i.e. wwwbasic.js, significantly modified), it took me all of 10 minutes to just go ahead and setup an IFF function.
Although not very BASIC-like, (javascript not being strongly typed) the IFF function works as-is for both strings and whatever numbers (so I'm kind of appreciating the no fuss no muss compactness).
Your workaround is quite lovely, though. That would make for an excellent include library.
Posts: 1,586
Threads: 59
Joined: Jul 2022
Reputation:
52
(06-03-2023, 10:59 PM)CharlieJV Wrote: BAM programs being interpreted by javascript (i.e. wwwbasic.js, significantly modified), it took me all of 10 minutes to just go ahead and setup an IFF function.
Although not very BASIC-like, (javascript not being strongly typed) the IFF function works as-is for both strings and whatever numbers (so I'm kind of appreciating the no fuss no muss compactness).
The Javascript version should work for any type including user-defined types, those that could have methods or not, but to assign values to the "properties". In QB64 one would have to write a new "IFF" function for each user-defined type, along the lines of my demonstration. Even if it involves a mere assignment such as "firstrecord = secondrecord".
Posts: 597
Threads: 110
Joined: Apr 2022
Reputation:
34
(06-05-2023, 02:54 PM)mnrvovrfc Wrote: (06-03-2023, 10:59 PM)CharlieJV Wrote: BAM programs being interpreted by javascript (i.e. wwwbasic.js, significantly modified), it took me all of 10 minutes to just go ahead and setup an IFF function.
Although not very BASIC-like, (javascript not being strongly typed) the IFF function works as-is for both strings and whatever numbers (so I'm kind of appreciating the no fuss no muss compactness).
The Javascript version should work for any type including user-defined types, those that could have methods or not, but to assign values to the "properties". In QB64 one would have to write a new "IFF" function for each user-defined type, along the lines of my demonstration. Even if it involves a mere assignment such as "firstrecord = secondrecord".
Just to be clear, BAM, although allowing some things to not be strongly typed (numeric vs string), BAM only allows standard types.
This IFF in BAM will only work with primitive types (string, integer, floating point).
BAM programs do not allow embedded javascript. Only BASIC things that are recognized by the interpreter.
Posts: 3,978
Threads: 177
Joined: Apr 2022
Reputation:
220
06-05-2023, 04:26 PM
(This post was last modified: 06-05-2023, 04:29 PM by bplus.)
Hi Charlie what does BAM do here?
Code: (Select All) Boolean = (7 < 8) ' this is a boolean expression NOT a string! that evaluates to 1 or -1
Print Boolean
Boolean = (7 > 8) ' this is a boolean expression NOT a string! that evaluates to 0
Print Boolean
I ask because IFF typically takes a numeric expression that evaluates to "True" or "False" numerically -1 or 1 and 0 for false.
mnrvovrfc had it setup correctly, I don't see where you are inferring a string expression for the first parameter.
b = b + ...
|