OpenEuphoria

Re: Constant Functions

• Posted by Irv <irv at ELLIJAY.COM> Aug 23, 2000
• 519 views

On Wed, 23 Aug 2000, John Coonrod wrote:
> A constant is a variable whose value cannot be changed once it is set.
>
> A function is a procedure that returns a value - like in math, sin(x)
> returns a value.

To elaborate just a bit:

A constant in most languages can contain a single value:
pi = 3.1415,
or
name = "Joe Blo"

however, in Euphoria, constants can be that, or any arbitrarily complex
object:
constant first_release = { "Irv Mullins", "irv at ellijay.com", 1.0, 12.99 }

where first_release[1] = my name
         first_release[2] = my e-mail
         first_release[3] = version # 1.0
         first_release[4] = price ($12.99)

These values are fixed. Any attempt to change them within the program
will cause an error.

Likewise, functions can accept, act upon, and return arbitrarily complex
objects:

function upgrade(object release)
release[3] += .1
release[4] += 2.00
return release
end function

obect newrelease

newrelease = upgrade(first_release)
After this call, everything in newrelease is the same as was in first_release,
except the version is now 1.1  and the price is 14.99

Regards,
Irv