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Difference between revisions of "VIATRA2/Examples/VTCL/Terms"
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| Line 87: | Line 87: | ||
Unary operators: | Unary operators: | ||
| − | * Minus: ''' | + | * Minus: '''-''' |
| + | For numerical values, they are treated as in Java, for instance. | ||
<source lang="text"> | <source lang="text"> | ||
| − | machine | + | machine arithmetic_terms_1 { |
rule main() = seq { | rule main() = seq { | ||
| − | print(3 + 4 | + | // Add |
| − | print(4.0 + 3); | + | print(3 + 4); |
| − | + | print(4.0 + 3); // also 3+4.0 is correct | |
| + | print(5.9 + 4.5); | ||
| + | // Subtract | ||
print(3 - 4.0); | print(3 - 4.0); | ||
| − | print(4 | + | print(4 - 3); |
| − | + | print(4.5 - 5.9); | |
| − | print(3 * 4 | + | // Multiply |
| + | print(3 * 4); | ||
print(4.0 * 3); | print(4.0 * 3); | ||
| − | + | print(5.9 * 4.5); | |
| + | // Divide | ||
print(10 / 4.0); | print(10 / 4.0); | ||
print(6.0 / 3); | print(6.0 / 3); | ||
| + | print(6 / 3); | ||
| + | print(9.0 / 4.5); | ||
| + | // Remainder: for integers | ||
| + | print(14 % 4); | ||
| + | } | ||
| + | } | ||
| + | </source> | ||
| + | |||
| + | Strings can be added with any other kind of terms, but no other operations are allowed. | ||
| + | |||
| + | <source lang="text"> | ||
| + | machine arithmetic_terms_2 { | ||
| + | rule main() = seq { | ||
| + | print(3 + "hello"); | ||
| + | print(3.9 + "hello"); | ||
| + | |||
| + | print("hello" + 4); | ||
| + | print("hello" + 3.4); | ||
| + | print("hello" + "test"); | ||
| + | print("hello" + true); | ||
| + | print(false + "hello"); | ||
| + | print("hello" + one_to_many); | ||
| + | print(many_to_one + "hello"); | ||
} | } | ||
} | } | ||
</source> | </source> | ||
Revision as of 10:55, 17 February 2009
VTCL Terms and Expressions
Constants
The followind types of constants are available in VTCL:
- Undefined value constant: undef
- Boolean constants: true, false
- Integer constants: 1, -1,
- Double constants: 2.32, -1.9, (as in Java)
- String constants: "A string." (as in Java)
- Model element constants: fully qualified names, e.g. uml.metamodel.Classifier, local names: ejbEntity, 'Class' (local names starting with a capital letter should be included within quotes.
- Multiplicity constants: one_to_one, one_to_many, many_to_one, many_to_many,
In case of model element constants, a corresponding element should be present in the model space (at compile time), otherwise an error message is issued.
machine vtcl_constants {
rule main() = seq {
// Undefined constant
println(undef);
// Boolean constants
println(true);
println(false);
// String constants
print("Hello VIATRA2 world!");
// Integer constants
println(4);
println(-4);
// Double constants
print(4.6);
print(-4.7);
print(6.6e2);
print(10e-2);
// Model elemenent constants
// (provided that entity testing.models.manager exists in model space)
print(fqn(testing.models.manager));
print(fqn('testing'));
// Multiplicity constant
print(one_to_one);
print(one_to_many);
print(many_to_one);
print(many_to_many);
}
}
Logical Terms
Logical terms consist of usual binary Boolean operators such as "&&" (and), "||" (or), "xor" (exclusive or), and unary operator "!" (not).
The precedence of Boolean operators are as follows: "!" (highest), "&&", { "||"; "xor" } (lowest). Operator precedence can be overridden by parenthesis. All previous operators tie as usual (to the left)
Equality (and inequality) operators, namely, "==" (equal), and "!=" (not equal), are also allowed for Boolean values.
There are two logical constants: "true" and "false".
machine logical_operators{
rule main() = seq {
print(!true);
print(!false);
print(true && false);
print(true || false);
print(true xor false);
print(true == true);
print(false != true);
// The internal pairs of parenthesis are not needed
print((true && false) || (true && true));
print((true == true) != false));
// The internal pairs of parenthesis are needed
print((true || false) && (true || false));
print(true == (true != false));
}
}Arithmetic Terms
Arithmetic terms can be constructed by binary and unary operators in the following way:
Binary operators
- Additive: + (add), - (subtract)
- Multiplicative: * (multiply), / (divide), % (remainder, only for integers)
Unary operators:
- Minus: -
For numerical values, they are treated as in Java, for instance.
machine arithmetic_terms_1 {
rule main() = seq {
// Add
print(3 + 4);
print(4.0 + 3); // also 3+4.0 is correct
print(5.9 + 4.5);
// Subtract
print(3 - 4.0);
print(4 - 3);
print(4.5 - 5.9);
// Multiply
print(3 * 4);
print(4.0 * 3);
print(5.9 * 4.5);
// Divide
print(10 / 4.0);
print(6.0 / 3);
print(6 / 3);
print(9.0 / 4.5);
// Remainder: for integers
print(14 % 4);
}
}Strings can be added with any other kind of terms, but no other operations are allowed.
machine arithmetic_terms_2 {
rule main() = seq {
print(3 + "hello");
print(3.9 + "hello");
print("hello" + 4);
print("hello" + 3.4);
print("hello" + "test");
print("hello" + true);
print(false + "hello");
print("hello" + one_to_many);
print(many_to_one + "hello");
}
}