Set Flag

Shared memory for the whole map: not a number and not an object, just a «yes» under a name

mediumYou need: What a world processor is, Shared memory

steptick 0

Get Flag0

resultflag

Jump -> 41

if ==

Print2

Print Flush3

Operation4

=

+

End5

@counter0number

alarmnullnull

checksnullnull

setflag "alarm" true

After two seconds the lower processor raises a flag, the upper one sees it and prints a warning. There is no link between them — only a shared flag name.

Field	What is in it
first	the flag’s name: a string, not a variable
second	the value: true or false

A flag is only “yes” or “no”

A flag’s value is one of two. A number, an item or a unit cannot be put into it: any value is reduced to truth by the same rules as in jump — zero and emptiness are false, everything else is true.

setflag "waveIncoming" 1        # true
setflag "waveIncoming" 0        # false

Silent failure

A flag’s name is a string, and only a string. Not setflag alarm true but setflag "alarm" true: without quotes that is a variable, and the flag simply is not raised — silently, as always.

The name can be assembled, though: a variable holding a string will do, and that is how named flags are made per player or per point on the map.

How a flag differs from a cell

	A flag	A memory cell
what it holds	“yes” or “no”	any numbers and objects
how many	as many names as you like	64 or 512 slots
who sees it	any processor on the map	only those linked to it
where it lives	in the running game	in a block on the map
who else reads it	the map’s objectives	nobody

The last row is the main one. Flags are the shared language of a world processor and the map’s objectives: the editor has a “such and such flag is raised” condition, and it is satisfied by exactly this set.

So a script is usually built like this: the processor watches what happens and raises a flag, and the map’s objective sees it and marks the task done.

Note

A memory cell has to be placed, a link has to be run to it, and it breaks together with the building. A flag needs none of that — it lives in the game itself. The other side of it: no number and no list fits into it.

Remember

• setflag "name" value raises or lowers a global flag.
• The value is binary only: zero and emptiness are false, everything else true.
• The name is written as a string, in quotes; it can be assembled from a variable.
• Flags are visible to every processor on the map and to objectives in the editor.
• Numbers and objects do not fit into a flag — a memory cell is for that.

Task

Change the lower processor’s setflag "alarm" true to setflag "alarm" false: the upper one stops printing the warning, although the flag is still being “set”.

Then remove the quotes — setflag alarm true. Nothing breaks and nothing happens: the name has become an empty variable.