State Scope

State Scopes allow to define Variable Declarations, Signal Declarations, and Local Reactions:

{SimpleScope} declarations+=(VariableDeclaration | SignalDeclaration | LocalReaction)*;

Variable Declarations

Variable Declarations in a State Scope are visible in this state and its descendant states.

A Variable:

has a Direction. It can be an input, an output, or both,
can be Static (optional),
has a Datatype (integer, boolean, real, string, void),
has an Name,
can be initialised (optional),
can get a CombineOperator(optional) (-, +, *, max, min, or, and, host).

{VariableDefinition} (isInput?='input')? (isOutput?='output')? (isStatic?='static')? type=[types::Type|FQN] name=ID
('=' varInitialValue=Expression)? ('with' varCombineOperator=CombineOperator)? ';';

Examples:

input boolean A;
output boolean A;
input output boolean A; // double direction (input and output))
input static boolean A; //static variable
boolean A; //local, without direction
input integer I=10; //the variable I is initialised
input integer I with '+' //the combine operator is '+'

KIELER Project > Yakindu-SCCharts textual desciption language > image2012-12-5 22:52:55.png

Signal Declarations

Yakindu events are interpreted as signals. A signal has a Direction and a Name.

{EventDefinition} (isInput?='input')? (isOutput?='output')? 'signal' name=ID ';';

Examples:

input signal I;
output signal I;
input output signal I;
signal I;

	advantage	disadvantage
Don't use signals	no need to be implemented	no signals	No
Boolean variables as signals	implementation in a short time a short form declaration: *in I* instead of *in I:boolean* a short form of use: I / O instead of [I==true] / O = false	no more possible to use of Boolean variables	No
Yakindu events as signals	use of already implemented features differ between Signals and Boolean Variables Declaration: in signal I;	signals are implemented as events Question: How to mix Signals and variables?	Yes
New declaration type	differ between Signals and Boolean Variables Declaration: in signal I;	expensive	no

KIELER Project > Yakindu-SCCharts textual desciption language > image2013-1-24 13:11:18.png

Local Reactions

A Local Reaction has a Trigger and an Effect.

(trigger=(LocalReactionTrigger | ReactionTrigger))? ('/' effect=(ReactionEffect | SuspendEffect)) ';';

LocalReactionTrigger

{ReactionTrigger} triggers+=LocalReactionType ('&&' (isImmediate?='#')? (delay=INT)? ((triggers+=RegularEventSpec) | ('[' guardExpression=Expression ']'))?)?;

Examples:

Entry && S
During && S
Exit && S
Exit && [S1 &&S2]
Entry && # S
Entry && # 3 S

LocalReaction Effect

{ReactionEffect} actions+=Expression (=> ',' actions+=Expression)*;

Example:

I / Suspend;
/ O=false;
/ I1=true, I2=false;
/ I1=true, I2=false;
/ O=true;

Transition

A Transition is defined by a Reaction, consisting of a Trigger and an Effect.

KIELER Project > Yakindu-SCCharts textual desciption language > image2013-1-24 13:22:48.png

Transition Trigger

A trigger:

can be a Signal,
a boolean Variable
an Expression
can be immediate (optional)
delay (optional)

{ReactionTrigger} (isImmediate?='#')? (delay=INT)? ((triggers+=RegularEventSpec) | ('[' guardExpression=Expression ']'));

Examples:

S
[S1 && S2]
#_S
#_3 S

Transition Effect

{ReactionEffect} actions+=Expression (=> ',' actions+=Expression)*;

Examples:

/ S
/ I = false
/ I1 = false, I2 = I3 + 10

State Scope

Variable Declarations

Signal Declarations

Local Reactions

LocalReactionTrigger

LocalReaction Effect

Transition

Transition Trigger

Transition Effect

Extending the Validator