The following metasyntax applies:
Symbol | Meaning |
:= | Definition |
< > | SDF data type |
m..n | Value range |
... | Repetition |
/ | Alternative entry |
[ ] | Optional entry |
The SDF data types <composed-name> and <structured-name> are used for variable names and partial variable names in SDF-P in the command syntax. However, the syntax checked by SDF-P is restricted in comparison with these data types and is therefore described here in more detail.
A variable name (composed-variable-name) in SDF-P consists of one or more structure names (structured-variable-name) separated from each other by periods. The period in each case marks the name of a substructure. Blanks are not permitted within a variable name.
composed-variable-name:=structured-variable-name[.structured-variable-name] |
Length at least 1 character, not more than 255 characters
Example
ABCDEFGHIJKLMNO#l A#l A123#l BCD.XYZ
A structure name consists of a partial variable name (pvn) which, if it refers to a list element or an array element, may be followed by a # and an index name.
structured-variable-name := pvn [# [indexname]] |
| Length | at least 1 character, not more than 20 characters |
| Partial variable | name (pvn): |
Character set | all letters (A, ... Z) |
First character | a letter |
| Conventions | The string SYS at the beginning of a variable name is reserved for system variables, and should not be used. A hyphen may not be directly followed by another hyphen. The hyphen must not be the last character of the partial variable name. |
Example
AREA-CODE CLIENT#NUMBER
If the structure name refers to a list element or an array element, it is followed by a # and an index name.
indexname = <integer -2147483648..2147483647> / pvn |
Example
TELEPHONE#223366 TELEPHONE#INDEX
Element names
In the case of element names, a distinction must be made between array elements, list elements and structure elements.
The syntax that is described under <composed-variable-name> also applies to element names.
List element names
List element names consist, at the user interface, of the following components:
list name (<composed-variable-name 1..253>)
#
optional: element number (<integer 1..2147483647>)
Array element names
Array element names are made up of the following components:
array name (<composed-variable-name 1..253>)
# (identifier for array elements when followed by additional characters)
array index (<integer -2147483648..2147483647>)
Both the list index and the array index can also be identified by a simple variable that contains an integer value within the range of valid values.
SDF-P analyzes the string that follows the aggregate symbol # in the element name: If the first character is a digit or hyphen (= minus sign), the string is interpreted as an integer value, i.e. as a direct entry of the index.
If the first character is a letter, the string is interpreted as a variable name. SDF-P then searches for a variable with the specified name. This name must refer to a simple variable, which must be initialized with a valid integer value. If this is not the case, an error message is issued. If the variable contains a valid integer value, this value is used in the array index or list index, and the aggregate element thus identified is accessed.
Example 1
ACCOUNT is a simple array. The array index can be specified in the array element name directly:
ACCOUNT#123
However, the array index can also be supplied by means of the variable INDEX:
/INDEX = 236 /SHOW-VAR ACCOUNT#INDEX
The string INDEX is recognized as a variable name and the variable contents are evaluated. Consequently, the SHOW-VARIABLE command outputs the contents of the array element ACCOUNT#236. Note, however, that the array element ACCOUNT#236 must have been declared and initialized previously.
Example 2
The array index entry is always evaluated as an integer value. Thus, the following entries designate the same element of the array ACCOUNT:
ACCOUNT#123 ACCOUNT#0123 ACCOUNT#00123 ACCOUNT#NUMBER
A prerequisite for the ACCOUNT#NUMBER entry is that a variable NUMBER has been declared and initialized with the value 123.
Structure element names
Structure element names are made up of the following components:
structure name (<composed-variable-name 1..253>)
“.” (identifier for structures)
element subname (<structured-variable-name 1..20>)
Example
The following variables are elements of the structure ADDRESS:
ADDRESS.SURNAME ADDRESS.FORENAME ADDRESS.TITLE ADDRESS.STREET