Bartels User Language - Programmer's Guide A.1 Conventions

This section describes the basic conventions for accessing the User Language index variable types and system functions.

A.1.1 Interpreter Environment

Each Bartels AutoEngineer program module providing the User Language Interpreter facilities is called an interpreter environment. Different sets of User Language index variable types and/or system functions are implemented and/or available in different interpreter environments. Each User Language program can be called just from those interpreter environments containing all of the User Language index types and system functions referenced by the program.

A.1.2 Caller Type

The User Language caller type is defined to support User Language program compatibility checks. A caller type is a coded value which represents a set of compatible User Language interpreter environments. Each User Language index variable type and each User Language system function is assigned to a certain caller type, which designates the compatible interpreter environment(s). The User Language Compiler combines the caller types of the program's system references (unless the #pragma ULCALLERSTD preprocessor statement is used; see chapter 2.6.5 for details). The resulting program caller type must match a valid set of interpreter environments (otherwise no valid program can be generated). When calling a User Language machine program, the User Language Interpreter checks whether the caller type associated with the program is compatible to the current interpreter environment (otherwise the program cannot be executed).

Table A-1 contains the list of Bartels User Language caller types.

Table A-1: User Language Caller Types

Table A-2 contains the information about the compatibility of the Bartels User Language caller types. According to this table the User Language Compiler performs a compatibility test for the system references of a program. All User Language index variable types and system functions referenced by a program must be assigned to a set of compatible caller types.

Table A-2: Compatibility Caller Type versus Caller Type

Table A-3 contains the information about the compatibility of the Bartels User Language caller types to the Bartels User Language Interpreter environments. According to this table the User Language Interpreter accomplishes compatibility checks on the User Language programs to be called. A User Language program can only be executed, if the program's caller type is compatible to the current interpreter environment.

Table A-3: Compatibility Caller Type versus Interpreter

Conventions
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