XLANG-s Variables and Operators
This section discusses the variables and operators used in the XLANG/s language.
XLANG/s Variables
Variables represent storage locations. Every variable has a type that determines what values can be stored in that variable. XLANG/s is type-safe, and its compiler guarantees that values stored in variables are always of the appropriate type. XLANG/s supports the following variable types:
Messages
Correlation sets
Service links
Ports
Distinguished built-in value types: Boolean, Byte, Char, Decimal, Double, Int16, Int32, Int64, SByte, Single, String, UInt16, UInt32, and UInt64
Objects
Enumeration types
XLANG/s provides initialization semantics for each of the preceding types. Such initialization can be viewed as an assignment to a variable of that type. In XLANG/s, a variable must be definitely assigned before its value can be obtained or used.
XLANG/s Operators
XLANG/s supports the following operators. They adhere closely to the functionality of the corresponding operators in C#.
| Operator | Description | Example |
|---|---|---|
| checked | Raises error on arithmetic overflow | checked(x = y * 1000) |
| unchecked | Ignores arithmetic overflow | unchecked(x = y * 1000) |
| new | Creates an instance of a class | myObject = new MyClass; |
| typeof | Retrieves a type | myMapType = typeof(myMap) |
| succeeded | Tests for successful completion of transactional scope or orchestration | succeeded(<transaction ID for child transaction of current scope or service>) |
| exists | Tests for the existence of a message context property | BTS.RetryCount exists Message_In |
| + | Unary plus | +(int x) |
| - | Unary minus | -(int x) |
| ! | Logical negation | !myBool |
| ~ | Bitwise complement | x = ~y |
| () | Cast | (bool) myInt |
| * | Times | Weight = MyMsg.numOrders * 20 |
| / | Divided by | x / y |
| + | Plus | x + y |
| - | Minus | x - y |
| << | Shift left | x << 2 |
| >> | Shift right | x >> 2 |
| < | Less than | If (MyMsg.numOrders < 10)... |
| > | Greater than | If (MyMsg.numOrders > 10)... |
| <= | Less than or equal to | If (MyMsg.numOrders <= 10)... |
| >= | Greater than or equal to | If (MyMsg.numOrders >= 10)... |
| == | Equal to | If (MyMsg.numOrders == 10)... |
| != | Not equal to | If (MyMsg.numOrders != 10)... |
See Also
XLANG-s Data Types
XLANG-s Statements
XLANG-s Expressions
XLANG-s Reserved Words
XLANG-s to BPEL4WS Type Conversions