JUST now learning functions

[Paul]

Hehe... I'm just now using functions, having not looked that way b4, I'm a little embarrassed. But I had to make something with functions, am I doing it properly?

(we were suppose to only use 2 global variables maximum)

code:

const grav := 9.8 var speed, angle : real put "Enter Speed: " .. get speed put "Enter Angle: " .. get angle function Vhor (speed, angle : real) : real     result speed * (cosd (angle)) %Vhor = speed*(cosd(angle)) end Vhor function Vvert (speed, angle : real) : real     result speed * (sind (angle)) %Vvert = speed*(sind(angle)) end Vvert function TimeMaxHeight (yspeed : real) : real     result yspeed / grav %Time to max height = Vvert/gravity end TimeMaxHeight function FlightTime (tim : real) : real     result tim * 2 %Flight time = TimeMaxHeight * 2 end FlightTime function Range (xspeed, flight : real) : real     result xspeed * flight %Range = Vhor * flight time end Range function MaxHeight (yspeed, MaxHTime : real) : real     result yspeed * MaxHTime - 0.5 * grav * MaxHTime ** 2 %MaxHeight = Vvert*Tmaxheight - 0.5(grav)(maxHTime**2) end MaxHeight put "The Time of Flight of the projectile is: " .. put FlightTime (TimeMaxHeight (Vvert (speed, angle))) : 0 : 2, " seconds" put "The range of the projectile is: " .. put Range (Vhor (speed, angle), TimeMaxHeight (Vvert (speed, angle))) : 0 : 2, " metres" put "The Maximum height of the projectile is: " .. put MaxHeight (Vvert (speed, angle), TimeMaxHeight (Vvert (speed, angle))) : 0 : 2, " Metres"

[wtd]

Yes and no. You're trying to save typing time by using things like "Vvert", but you're just costing yourself far more time down the road figuring out what the heck you meant.

Try "verticalVelocity" and "horizontalVelocity".

[Paul]

Those were just fromt he formulas, everything else ok?

[Delos]

They look like they serve their purpose. Here's a little something that people often overlook about functions:

code:

function world : string result "hello world" end world put world

Functions don't need parameters - kinda obvious, but as I said often overlooked.
And why is this useful? Well, it's circumstantial to be sure. I found it particularly useful when dealing with arrays of custom types, where multiple constant assignments need to be made.

[wtd]

Delos wrote:

They look like they serve their purpose. Here's a little something that people often overlook about functions:

code:

function world : string result "hello world" end world put world

Functions don't need parameters - kinda obvious, but as I said often overlooked.
And why is this useful? Well, it's circumstantial to be sure. I found it particularly useful when dealing with arrays of custom types, where multiple constant assignments need to be made.

Turing does provide for constants.

code:

const world := "hello world"

Less code and it says what you meant when you wrote the function above.

[Delos]

What! Constants in Turing! OMG! That's so freakin' awsome!



Come on wtd, you know as well as I, actually a lot better than I, how useful fcns can be. And yes I admit the above example was plain and could have been done using the whole constants approach, but the concept is what I was after.
Think about it, you have a record-type, with say 20 different fields in it. And then you make a nice array of those, and you want to set those up, all to the same value. Use a parameterless fcn.
I have this nagging feeling that you're going to post something that is several times more efficient that this method...I just know it. In that case, there are *other* places where parameterless fcns make for good usage!

[wtd]

Yes, I do know the value of functions, but use what's most expressive.

I wish I could offer something more efficient, but Turing doesn't provide for record literals.

One possible solution is simply to prove good defaults.

code:

record    hello : int := 42    world : string := "foo" end record

[Cervantes]

I don't think turing will let you assign values to hello and world, the elements within your record. I think you must assign your values outside the record.

[Delos]

Quite right Cervantes.

Once again, the limitations of OOT are exposed...

[Paul]

Well, the point of the program is actually parameter passing. We were just suppose to do something with less than 2 global variables.
You can find it here actually
http://www34.brinkster.com/paulbian/projectile.doc

[wtd]

Huh... could have sworn you could do that.