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assert(prog_tools) Prog_Tools assert(prog_tools)

NAME

assert - checks a condition and prints an error message if the condition fails

DESCRIPTION

The assert object is similar to the assert macro in the C programming language. Instances of the assert class can be used throughout scripts to document various assumptions and print error messages when the assumptions are violated. By default, a failed assertion will cause the parser to exit, but this can be changed by sending a continue_on_failure_on! message to the instance (or the assert class to affect the behaviour of all subsequently created assertions). The assert class is a subclass of logic. Therefore, all messages valid with a logic object are also valid with assert objects.

SUPERCLASS

logic

INSTANCE VARIABLES

continue_on_failure a boolean value that indicates what should happen on a failed assertion. If this variable is set to true, the normal error message will be printed out but the parser will continue. If the variable is set to false (the default), then the parser will exit once the error message is printed out.

checking_for a string value that is printed out if the assertion fails.

MESSAGES

continue_on_failure_off! causes execution to stop after a failed assertion. An error message is printed out indicating the failed assertion.

continue_on_failure_on! causes execution to continue after a failed assertion. The error message is still printed out however.

check! checks the value of the assertion. If it is nonzero, an error message is printed out. Execution is suspended if the continue_on_failure instance variable is set to false.

checking_for[=?] set/get the value of the checking_for instance variable.