how to define a struct function? [solved]

hebdemnobad · 13-Dec-2014 19:15:01

colleagues:

this was partially discussed in another thread, but i figured i would start a new one for clarity.

let's say I have a 'dog' struct. it has two properties: it's barking volume (a float), and its barking sound (a string). alot of this is psuedo code because i don't know how to declare a function in scol in any concrete way:

struct Dog =[
	fdog_volume				: F,
	sdog_bark				: S,
	//psuedo code from what i know of scol
	bark						:  fun [Dog F S] S
	
	/*psuedo code, loosely based on vbnet or java or javascript
	fun dog.bark()=
		_fooS strcatn "Dog is this loud: ":: (ftoa dogfidog_volume):: "and it sounds like this: ": (sdog_bark)::nil;;
	*/
		  ] mkDog;;
		  
fun main()=
	_showconsole;
	let 2.0 -> dog_volume in
	let "arfarfar"-> dog_bark in
	let mkDog [	dog_volume dog_bark] -> newdog in
	//open let brace
	(
	//is there a way to invoke the 'bark' function without having to something like this, i know it's very incomplete in any case:
	exec newDog.fun_dog_bark with [newdog.idog_volume newdog.sdog_bark];
	//this would be psuedo code based on the other languages i know
	newdog.bark;
	//close let brace
	);
	
	0;;

Last edited by hebdemnobad (14-Dec-2014 22:44:12)

iri · 13-Dec-2014 22:15:43

Quickly, you could write this :

struct Dog =[
	fdog_volume				: F,
	sdog_bark				: S,
	fun_bark				: fun [Dog] S
	] mkDog;;
	
// you define the function outside the structure. Its prototype is : fun [Dog] S
fun fooBark (dog)=
	_fooS strcatn "Dog is this loud: ":: (ftoa dogfidog_volume):: "and it sounds like this: ": (sdog_bark)::nil;;

fun main()=
	_showconsole;

	let mkDog [
		nil    // fdog_volume
		nil    // sdog_bark
		nil    // fun_bark
		] -> newdog in
	//open let brace
	(
	set newdog.fdog_volume = 2.0;
	set newdog.sdog_bark = "arfarfar";
	set newdog.fun_bark = @fooBark;	// "@" is approximately equals at the pointer of function

	exec newdog.fun_bark with [newdog];
	);
	
	0;;

You can initialize the structure either by setting these fields, as here, or directly as you did. As you want, the result is the same. Sometimes, according the context, one of these method can be better.

hebdemnobad · 13-Dec-2014 23:00:37

Thx Iri

iri · 14-Dec-2014 00:16:35

fun fooBark (dog)=
	_fooS strcatn "Dog is this loud: ":: (ftoa dog.fdog_volume):: "and it sounds like this: ": (dog.sdog_bark)::nil;;

It should be more correct

hebdemnobad · 16-Dec-2014 16:49:45

thx iri, dogs are the best examples for object oriented (or pseudo object oriented) programming, for some reason.

Scolring - Forum

#1 13-Dec-2014 19:15:01

how to define a struct function? [solved]

#2 13-Dec-2014 22:15:43

Re: how to define a struct function? [solved]

#3 13-Dec-2014 23:00:37

Re: how to define a struct function? [solved]

#4 14-Dec-2014 00:16:35

Re: how to define a struct function? [solved]

#5 16-Dec-2014 16:49:45

Re: how to define a struct function? [solved]

Board footer