Description of the function calls

Function calls

The notation adopted for describing the function calls is:

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CALL SDF(<parameterlist>)

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The contents of <paramlist> are shown in the description of the function call. The exact syntax of the call varies depending on the language.

Notational conventions

Since the exact syntax of the function calls is language-dependent, certain notational conventions have been adopted for the descriptions below. The parameter list always appears in parentheses (). Square brackets inside the parameter list always enclose an optional parameter or parameters.

The list itself is always followed by a tabular description:

Column 1:	Name of the parameter
Column 2: Column 3:	Data type of the parameter and its length. The following data types occur:
	char integer ptr V-rec@ in out inout	character string integer (always 4 bytes long) address address of a variable-length record input parameter output parameter input/output parameter
Column 4:	Explanatory remarks

Information returned by the functions

Each function returns information in the form of a return code. SDF writes this return code into the “error” parameter, which must be present in the parameter list of each function.

The return codes may belong to one of three classes:

error=0:	Command executed without error.
error>0:	Error in the associated macro. The error code has been copied from register 15 into the ’error’ parameter. The value of the error code corresponds to that of the macro error code.
error<0:	-1 :	Function unknown
	-2 :	Not enough operands
	-3 :	Last operand in structure reached
	-4 :	Last operand in list reached
	-5 :	Position is negative
	-6 :	Operand is not of the type LIST
	-7 :	Operand is not of the type STRUCTURE