Teledyne LeCroy Protocol Analyzers File-Based Decoding User Manual - Manual (Page 14)

Chapter 3: Expressions File-based Decoding User Manual
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LeCroy Corporation
3.1 select expression
The select expression selects the value to which it evaluates based on Boolean
expressions. This is the format for a select expression:
select {
: 
: 
...
};
The expressions are evaluated in order, and the statement that is associated with the first
true expression is executed. That value is what the entire expression evaluates to.
x = 10
Value_of_x = select {
x < 5 : "Less than 5";
x >= 5 : "Greater than or equal to 5";
};
The above expression evaluates to “Greater than or equal to 5” because the first true
expression is x >= 5. Note that a semicolon is required at the end of a select
expression because it is not a compound statement and can be used in an expression
context.
There is also a keyword default, which in effect always evaluates to true. An example
of its use is
Astring = select {
A == 1 : "one";
A == 2 : "two";
A == 3: "three";
A > 3 : "overflow";
default : null;
};
If none of the first four expressions evaluates to true, then default is evaluated,
returning a value of null for the entire expression.
select expressions can also be used to conditionally execute statements, similar to C
switch statements:
select {
A == 1 : DoSomething();
A == 2 : DoSomethingElse();
default: DoNothing();
};
In this case the appropriate function is called depending on the value of A, but the
evaluated result of the select expression is ignored.