VAR, ARRAY and STR <initialization> Parameter
Ada Test Script Language
Purpose
In conjunction with the VAR, ARRAY and STR keywords, the <initialization> parameters for Ada specify the initial value of the variable.
Syntax
INIT = <exp>
INIT IN ( <exp>, <exp>, ... )
INIT ( <variable> ) WITH ( <exp>, <exp>, ... )
INIT FROM <exp> TO <exp> [STEP <exp> | NB_TIMES <nb> | NB_RANDOM <nb>[+ BOUNDS]]
INIT FROM <exp> TO <exp> [STEP <exp> | NB_VALUE <nb> | NB_RANDOM <nb>[+ BOUNDS]]
INIT ==
where:
<exp> is an expression as described below.
<nb> is an integer constant that is either literal or derived from an expression containing native constants
<variable> is an Ada variable
Description
The <initialization> expressions are used to assign an initial value to a variable. The initial value is displayed in the Component Testing report for Ada.
The INIT value is calculated during the preprocessing phase, not dynamically during test execution.
Initializations can be expressed in the following ways:
INIT = <exp> initializes a variable before the test with the value <expression>.
INIT IN { <exp> , <exp> , ...} declares a list of initial values. This is a condensed form of writing that enables several tests to be contained within a single instruction.
INIT (<variable>) WITH { <exp> , <exp> , ...} declares a list of initial values that is assigned in correlation with those of the variable initialized by an INIT IN instruction. There must be the same number of initial values.
INIT FROM <lower> TO <upper> allows the initial value of a numeric variable (integer or floating-point) to vary between lower and upper boundary limits:
STEP: the value varies by successive steps.
NB_TIMES <nb> or NB_VALUE <nb>: the value varies by a number <nb> of values that are equidistant between the two boundaries, where <nb> >= 2 (NB_TIMES and NB_VALUE are equivalent keywords). This option requires that the target platform supports floating point numbers.
NB_RANDOM <nb>: the value varies by generating random values between the 2 boundaries, including, when appropriate, the boundaries, where <nb> >= 1. This option
The INIT IN and INIT (<variable>) WITH expressions cannot be used with for arrays that were initialized in extended mode or for structures.
The INIT FROM expression can only be used for numeric variables.
The STEP syntax cannot be used when the same variable is tested by another VAR, ARRAY or STR statement.
The NB_TIMES, NB_VALUE, and NB_RANDOM keywords require that the target platform supports floating point numbers.
An initialization expression can still be used (INIT == <expression>) to include of expected value expression when using the INIT pseudo-variable is used. See Expected_Value Expressions.
Expressions
The initialization expressions <exp> can be among any of the following values:
Numeric (integer or floating-point), character, or character string literal values. Strings can be delimited by single or double quotes
Native constants, which can be numeric, characters, or character strings
Variables belonging to the test program or the module to be tested
Ada functions
The keyword NIL to designate a null pointer
Pseudo-variables I, I1, I2 ..., J, J1, J2 ..., where In is the current index of the nth dimension of the parameter and Jm the current number of the subtest generated by the test scenario's mth INIT IN, INIT FROM or LOOP; the I and I1 variables are therefore equivalent as are J and J1; the subtest numbers begin at 1 and are incremented by 1 at each iteration
An Ada expression with one or more of the above elements combined using any operators and casting, with all required levels of parentheses, the + operator being allowed to concatenate character string variables
For arrays and structures, any of the above-mentioned expressions between brackets ('[]') for Ada, including when appropriate:
For an array element, part of an array or a structure field, its index, interval or name followed by '=>' and by the value of the array element, common to all elements of the array portion or structure field
For structures you can test some fields only, by using the following syntax:
[<fieldname> => <value>, <fieldname> => <value>]
The keyword others (written in lower case) followed by '=>' and the default value of any array elements or structure fields not yet mentioned
For INIT IN and INIT WITH only, a list of values delimited by brackets ('[]') for Ada composed of any of the previously defined expressions.
Additional Rules
Any integers contained in an expression must be written either in accordance with native lexical rules, or under the form:
<hex_integer>H for hexadecimal values. In this case, the integer must be preceded by 0 if it begins with a letter
<binary_integer>B for binary values
Note Because of the way hexadecimal values are handled, the value range should not exceed half of the maximum range when the initialization is expressed in hexadecimal.
The number of values inside an INIT IN parameter is limited to 100 elements in a single VAR statement.
The number of INIT IN parameters per TEST LOOP block is limited to 7.
The number of INIT IN parameters per TEST block is limited to 8.
In Component Testing for Ada, if variables are used in the expression, then the test evaluate the the INIT value with variable values from before the execution.
Example
VAR x, INIT = pi/4-1, ...
VAR y[4], INIT IN ( 0, 1, 2, 3 ), ...
VAR y[5], INIT(y[4]) WITH ( 10, 11, 12, 13 ), ...
VAR z.field, INIT FROM 0 TO 100 NB_RANDOM 3, ...
VAR p->value, INIT ==, ...
ARRAY y[0..100], INIT = sin(I), ...
ARRAY y, INIT = (50=>10,others=>0), ...
STR z, INIT = (0, "", NIL), ...
STR *p, INIT = (value=>4.9, valid=>1), ...
In the following example, the Ada test Script Compiler generates code that tests x against a then b before the execution of the code under test:
VAR y, init in (1,2), ev = init
VAR a, init(y) with ( 10, 20 ), ev = 50
VAR b, init(y) with ( 30, 40 ), ev = 70
VAR x, init(y) with (a, b), ev = init
#a := 50;
#b := 70;
Related Topics
VAR, ARRAY and STR | VAR, ARRAY and STR <variable> Parameter | VAR, ARRAY and STR <expected> Parameter