Language syntax¶
Basic types¶
Integers:
10
,-42
,+1337
Strings:
"Hello, world!"
Booleans:
true
,false
Maths¶
Basic maths are supported so you can do arithmetic or boolean logic:
1 + 1
b * b - 4 * a * c
(1 + 2) * 3
true || false
true || false && myVar
x % 2 == 0
Conditional execution¶
if (x == y) {
...
}
if (x < y) {
...
} else {
...
}
Loops¶
for (i in 0..10) {
...
}
Iterates in a range from 0 to 10 (inclusive).
You can also iterate on decreasing values:
for (i in 10..0) {
...
}
Iterates in a range from 10 to 0 (inclusive).
You can use «complex» expressions for the range bounds:
for (i in start..(a + b)) {
...
}
Printing data¶
display "hello";
display (1 + 2) * 3;
display true || false && true;
Prints three lines:
hello
9
true
Actor behavior definition¶
An actor behavior definition follows this pattern:
<actor type> (<state var1>, <state varN>) [<message item1>, <message itemN>] = <statements>
A behavior is executed when a message matching a pattern is received by an actor.
Example:
MyActor () [item1] = display item1;
MyActor (State) [item1, item2] = {
display item1;
display item2;
};
Tagged messages¶
To enable calling the right behavior of an actor with multiple behaviors of the same arity, one can tag the messages with literal values in the patterns.
Example:
MyActor () ["display-one"] = display 1;
MyActor () ["display-two"] = display 2;
These behaviors will be executed on receiving a message containing either "display-one"
or "display-two"
.
Changing behavior¶
An actor can change its type (and so its behavior) based on a received message:
Empty () ["set", x] = become Full (x);
Full (X) ["get", sender] = {
send [X] to sender;
become Empty ()
};
Sending messages¶
send [42] to anActor;
send ["hello", 1337] to anotherActor;
Actor self reference¶
In a behavior, the self
variable is a reference to the actor executing the code.
Creating actors instances¶
Instantiating an actor from a given type with a given state (e.g. MyActor (42)
) is done like so:
myInstantiatedActor = create MyActor (42);