12.3 Type and Range Checking

Warning: In this release, the No value for GDBN commands for type and range checking are included, but they do not yet have any effect. This section documents the intended facilities.

Some languages are designed to guard you against making seemingly common errors through a series of compile- and run-time checks. These include checking the type of arguments to functions and operators, and making sure mathematical overflows are caught at run time. Checks such as these help to ensure a program's correctness once it has been compiled by eliminating type mismatches, and providing active checks for range errors when your program is running.

No value for GDBN can check for conditions like the above if you wish. Although No value for GDBN does not check the statements in your program, it can check expressions entered directly into No value for GDBN for evaluation via the print command, for example. As with the working language, No value for GDBN can also decide whether or not to check automatically based on your program's source language. See section Supported Languages, for the default settings of supported languages.