A clump is a piece of code with a name, so you can use it again and again.

clump greet(name)
    oga "Hello " + name + "!"
unga

greet("Ugg")
greet("Oona")
greet("Grog")

The parts

clump double(n)          ugg name is double, one box called n
    ork n * 2            ugg give the answer back
unga                     ugg the clump ends here

oga double(21)           ugg use it: prints 42

• The names in parentheses are the clump's own boxes, called boxes or

parameters.

• ork hands a value back and stops the clump right there.
• A clump without ork gives back plop.
• Make the clump before you call it. The computer reads top to bottom.

Calling clumps

clump add(a, b)
    ork a + b
unga

oga add(2, 3)                    ugg 5
oga add(add(1, 1), add(3, 4))    ugg 9

You can also call a clump without using its answer, if the clump does something by itself:

clump cheer()
    oga "BOOGA BOOGA BOOGA"
unga

cheer()

Private boxes

Boxes made inside a clump are private. Changing them does not touch outside boxes unless you change an outside box's value in place (like adding to a pile):

grunk total = 0

clump add_to_total(n)
    total = total + n        ugg changes the OUTSIDE box
unga

clump makes_own(n)
    grunk total = 100        ugg makes a NEW private box
unga

add_to_total(5)
makes_own(999)
oga total                    ugg 5

Recursion: a clump that calls itself

This is the famous Fibonacci sequence:

clump fib(n)
    binga n < 2
        ork n
    unga
    ork fib(n - 1) + fib(n - 2)
unga

oga fib(10)      ugg 55

Every recursion needs a way to stop. Here, the binga n < 2 check is the stopping point. Without it, CMC catches the runaway and says:

OOGA! 'fib' called itself too many times and went too deep.
Hint: a clump can call itself, but it needs a way to stop. Use 'binga' to check.

The limit is about 200 levels deep.

Mistakes CMC catches for you

A worked example

clump temperature_name(celsius)
    binga celsius >= 30
        ork "hot"
    wonga binga celsius >= 15
        ork "nice"
    wonga
        ork "cold"
    unga
unga

zoop c in snorf(0, 20, 35)
    oga c, "degrees is", temperature_name(c)
unga

0 degrees is cold
20 degrees is nice
35 degrees is hot

Next: Piles.