4.2.5. Update Rule
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4.2.5. Update Rule

[Tip]Description

An update ruleis used to modify the value of an already defined variable or the value assigned to a specific location of an ASM function.

[Important]Syntax
UpdateRuleAST ::= update VariableRefAST = ArithmeticTermAST ;
                | update AsmFunctionUpdateLocationAST = ArithmeticTermAST ;

AsmFunctionUpdateLocationAST ::= ASMFunctionNameAST ActualParameterDefAST

ASMFunctionNameAST ::= ValueQualifiedNameAST
[Note]Semantics

The value of the variable or the ASM function locationreferred by the update ruleis updated to the value resulting from the evaluation of the ASM arithmetic term.

[Caution]Constraints

The variable in the update rule must be previously defined in a let rule, forall rule, choose rule, or in a formal parameter list. otherwise a compile-time error occurs.

The same restriction applies for the ASM function location: the referred ASM function must be already defined in one of the loaded machines otherwise a compile-time error occurs. Initialization of the corresponding ASM function is always given at the defining transformation module.

Defined In:  simple rule

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